Feast or Famine, The off grid solar dilemma.

[SamDeleted]

With isolators it doesn't matter if one battery chemestry is one volt up or down from the rest. The one with the higher volt will simply feed until it's down to the same level as the rest, and as batteries discharge more and more batteries En Banc will contribute.

The BMS shuts down any battery that gets anywhere near it's lower limit, or gets too cold, so there is that line of defense. I FINALLY have enough panels & batteries i don't have to watch every Watt.

Very interesting , makes sense


Now are you only doing this with Lithiums , or lead acids as well

 

[Zwy]

I only use non ethanol gas. I consider additives such as Pri G as a waste of good money.

Pri-G just works.

You are using a closed mind.

The only gas additive that actually worked was lead. For diesel you do need an anti-algae additive for long storage periods and a way to separate water.

For diesel, one should add an anti algae additive. Even if you think you will never have bio diesel in a tank, it still ends up in there. When a tanker or fuel truck is filled, how would you know what was last in the tank or in the hose?

Consumer gas additives often contain ethanol. Seems like a bad idea to buy ethanol free gas and end up adding it. It does serve a purpose as a dryer* as it allows moisture in the gas to be suspended in solution for safer combustion.

Closed mind theories..........

* Most gas dryers are wood alcohol or methanol instead of ethanol.

Isopropryl works better.

 

[SamDeleted]

It's basically a Diode.
A Diode is a one way gate valve for electrical current.

55A 1600V anti-back charge diode MD55A1600V anti-diode | eBay

What you see is what you get.

www.ebay.co.uk

Like this ?

 

[JeepHammer]

Very interesting , makes sense


Now are you only doing this with Lithiums , or lead acids as well

The isolators came in with lead/acid. I used big fork truck, true deep cycle, and they don't exactly get along with automotive style lead/acid.

Different age lead/acid in bank need a charge isolator, basically two chargers in one case.
The source (panels) to the charge isolator, then out to two (or more) different batteries.

The older battery will demand charge when the newer doesn't need it... cooked battery. Charge isolator stops that.
This was in the days before charge controllers, which basically does the same job with a lot less fuss or losses.

So now I have a battery a volt or two above the other batteries...
The isolator let's it contribute to the Buss, but keeps that extra two volts out of the other batteries that don't want and can't use those two extra volts.

The Buss can ALWAYS use the two 'extra' volts.

As soon as the battery with two extra volts drops to the same voltage as every other battery, everything contributes to the Buss voltage. That battery has a charge controller specifically for it, so I don't have to worry about charging it SPECIFICALLY from the Buss.

This wouldn't work with a combined unit that would be limited to Buss voltage as a maximum.
See all those combined, all in one inverter/chargers with a single charger output.

Don't get me wrong, the combined, single output charger works fine when your batteries are all matched in size, voltage, age, etc. It's just not optimum when you have older mixed with newer.

The 'losses' I have are comparable with with an all in one, it's just insurance for my modular, older with newer system.
The 'Extra' some batteries have isn't going to waste,and that 'Extra' more than exceeds the losses.

There is more than one way to skin this cat even though I take a lot of crap for having different chemestry, age, size batteries, panels, etc., and I don't have 'Designer' labels with slick logos...

 

[SamDeleted]

The Buss can ALWAYS use the two 'extra' volts.

As soon as the battery with two extra volts drops to the same voltage as every other battery, everything contributes to the Buss voltage. That battery has a charge controller specifically for it, so I don't have to worry about charging it SPECIFICALLY from the Buss

So basically good battery gets hit first because it's at a higher voltage



It sounds like a good way forward , great for me because weve got a lot of mixed batteries, mixed panels , and because of shading I'm going to have to have panels dotted all over the garden ,

Are you running 24v on this system?

 

[SamDeleted]

I'm all separate components, no all in ones

 

[JeepHammer]

55A 1600V anti-back charge diode MD55A1600V anti-diode | eBay

What you see is what you get.

www.ebay.co.uk

Like this ?

Exactly like that. Look at the schematic on the side, arrowhead points direction of current flow, the 'stripe' line in front of the arrow head shows it can't back feed.

That's the schematic symbol for a diode.

Schematics being specific engineering symbols for an electrical circuit, not to be confused with a diagram which shows devices and wires.

That's 55 amps, which an inverter can draw a LOT more than 55 amps.
The more batteries you have, the less amps gets drawn from each battery...

If you need to go over 55 amps, then these work just fine in parallel, they will share the load.

While *Some* people will complain about adding a diode, there are hundreds to thousands of diodes in every solar PV system.
Most of the little crap you see on a circuit board are diodes...

There are at least a half dozen in every simple voltage regulator, every rectifier (AC ro DC) has at least 6 in a generator, every better panel has bypass diodes installed, every combiner box has backfeed diodes, they are ubiquitous, simply everywhere...
So complaining about someone adding a diode here or there shows ignorance of how things actually work.

I buy mine from welding supply places.
Welders generate in AC, rectify to DC, and it's big amps. Since welders are ubiquitous, the big Amp diodes are common, and that makes them cheap.
They are all over the surplus markets since they are ubiquitous... in every size and shape.

The panel mount you found makes mounting stupid easy and easy to cover terminals if that's required.
When I buy the big, loose diodes, they have lug studs, I thread copper Buss material and use a copper nut on the back to lock them in place.

I make my own Buss bars, I don't confuse a 'Terminal' end with a large mass LUG needed for high amp/low resistance current. See about every battery/inverter cable for what NOT to do using those flattened tubing terminals instead of high amp lug.

If you want to move amps, you MUST have both mass, and contact patch area, the tubing side walls simply aren't the same mass as the battery terminal or cables in 99% of the cases...

Westinghouse - 1479-0182 - Diode. 75-150 Amp. Stud. Industrial High Current Diode.

Westinghouse - 1479-0182 - Diode. Industrial High Current Diode. Current: 75-100 Amp. Voltage: 50V Package: 3/8

www.electronicsurplus.com

The cable/terminal coming out of these can be combined for easy parallel wiring, or isolating one battery from another assuming you have different batteries in one case.

This assumes you need this much one way current capabilities...
These do generate a little heat, the copper Buss is an excellent heat sink when these things are running near full capacity.
I get a 'Hot Spot' I just add another diode in parallel and split the load between them, drops the heating issue entirely.

Stupid easy to test.
Multi-meter set to Continuity, check for current flow one direction, then switch probes on the terminals.
Continuity one direction but not the other. If you get Continuity both directions, one or more of the diodes have failed.

You can actually wire a (5 cent) LED in the opposite direction to these, if the big diode fails the 'Red' LED will light and let you know it's failed.
If its someplace important, use a common Diode to trip an alarm and/or disconnect switch.

They RARELY fail. I have isolation diodes that were salvaged from welders (used hard) and I've been running them for 30 years... It usually takes stupidity (I'm guilty) or lightening strike to kill them.

 

[SamDeleted]

Exactly like that. Look at the schematic on the side, arrowhead points direction of current flow, the 'stripe' line in front of the arrow head shows it can't back feed.

That's the schematic symbol for a diode.

Schematics being specific engineering symbols for an electrical circuit, not to be confused with a diagram which shows devices and wires.

That's 55 amps, which an inverter can draw a LOT more than 55 amps.
The more batteries you have, the less amps gets drawn from each battery...

If you need to go over 55 amps, then these work just fine in parallel, they will share the load.

While *Some* people will complain about adding a diode, there are hundreds to thousands of diodes in every solar PV system.
Most of the little crap you see on a circuit board are diodes...

There are at least a half dozen in every simple voltage regulator, every rectifier (AC ro DC) has at least 6 in a generator, every better panel has bypass diodes installed, every combiner box has backfeed diodes, they are ubiquitous, simply everywhere...
So complaining about someone adding a diode here or there shows ignorance of how things actually work.

I buy mine from welding supply places.
Welders generate in AC, rectify to DC, and it's big amps. Since welders are ubiquitous, the big Amp diodes are common, and that makes them cheap.
They are all over the surplus markets since they are ubiquitous... in every size and shape.

The panel mount you found makes mounting stupid easy and easy to cover terminals if that's required.
When I buy the big, loose diodes, they have lug studs, I thread copper Buss material and use a copper nut on the back to lock them in place.

Westinghouse - 1479-0182 - Diode. 75-150 Amp. Stud. Industrial High Current Diode.

Westinghouse - 1479-0182 - Diode. Industrial High Current Diode. Current: 75-100 Amp. Voltage: 50V Package: 3/8

www.electronicsurplus.com

Thank you Mr jeep hammer much appreciated

I might be back with some pics when I start getting things together

 

[Hedges]

I think the stabilizer/storage additives don't contain ethanol.
The cleaners, octane booster/anti-ping additives might. Certainly the ones for drying out water from system.

 

[JeepHammer]

So basically good battery gets hit first because it's at a higher voltage



It sounds like a good way forward , great for me because weve got a lot of mixed batteries, mixed panels , and because of shading I'm going to have to have panels dotted all over the garden ,

Are you running 24v on this system?

I'm 48 volts on one system, 96 on another.

48 volts for homes, cabins, common shop, 96 for the big crap in the shop.

The reason for 48/96 is cells.
I build 48v batteries, just series them for the 96v system. The 3 phase industral inverter won't run on less than 96 volts.

Since Lithium gets along with it's brothers, same cell size/age/chemestry, its just easier to build in 48 volts and series the batteries En Bank for 96 volts.
I'm lazy, I like the 'Easy' button a little too much...

Should any given 48 volt battery go lame, I have to take BOTH series batteries out since series only works EFFICENTLY when all cells are matched.

Then the 48 volt batteries go En Banc as 48 volts, on the 48 volt Buss. They work fine standing alone in that bank.
The better/newer will ALWAYS contribute to the Buss first, they are new and more efficient. That little top charge advantage goes completely away as soon as you do any real work, and every battery contributes to the Buss at it's given ability.

You paid a crap ton for the cells/battery, getting as much work out of it only returns more on investment, and there is still PLENTY of power in the older, weaker or smaller batteries.
The isolator lets them contribute what they can without beating anything else up.

It's MUCH cheaper to do 48 volt charge controllers, BMS, and a heck of a lot less headaches.

I can remember when it was difficult to get a 24 volt charge controller, and you still can't get a 48 volt generator without paying mega-bucks...
If you intend to go off grid, smaller scale, there wouldn't be anything wrong with 24 volt batteries. It's one heck of a lot cheaper when you consider a backup generator, etc.
All part of an off grid system, and the subsequent overall cost.

I use 48 volt locomotive alternators on my gas generator, my 3rd line defense against being in the dark.
300+ Amps, 48 VDC, around $3,000 (USD) each, but you can turn them with any engine above about 20 HP.

Alternator, generator and starter/DC motor repair was my first business after being disabled (military), I could do the job sitting down...

I like a specific type of alternator for this, it's less expensive, easy to modify.
I add extra rectifiers (diode Busses) to them so I can run them above rated output, and it's stupid easy to take control of the rotor current for additional output.
They also DO NOT have the Negative bonded to the case, an actual negative terminal, so the DC current connection is isolated.

The savings are in the case design & type. The 12 volt big truck alternator sportiness the case, rotor, field windings, etc.
Simply swap the regulator and rectifiers for the 48 volt version. In business for around $300 (USD) using the common 12 volt core, which is about $30 (USD) from the salvage yard.

Now, one set of rectifiers are EXTERNAL, if you touch them during operation it WILL electrocute you, completely dead if you get good contact. Not 'Idiot Proof' ...
But then again, I don't consider myself an idiot most times... And for 90% off retail I can build a screen wire or plexiglass guard.

 

[Hedges]

Diodes rectify, but have a voltage drop. Don't care much with generator or grid power.
For inverters and SMPS, usually a MOSFET is used in place of or in parallel with diode, for lower voltage drop (just a resistance) and less loss.

PV cells of course are a diode, but application is quite different. They are forward biased in the sun, and Voc is the voltage where conduction through the diode equals current production (no current flows to load.)

 

[Hedges]

I ran into a problem with stabil. I have been running it in about everything since I have like 40 vehicles and mowers and tractors etc to try to keep gas from going bad. The problem first showed up in my riding mowers. Its a gummy residue that clogs up the fuel bowl and the jets. I'm not sure if its happening in the larger vehicles but I had nothing but problems with that mower forming the crap and besides gas the stabil is all I used in it. Makes me a bit leery of the stuff now. Its been forming in weed eaters I have too.

How long do you let it sit?

HF gas engines, warranty says add stabilizer and operate every 2 or 3 months. Could it be the gumming up occurs with longer storage?
I've had their chipper about 4 years now. I add stabilizer to 5 gallon gas can, fill tank from can and do some chipping every few months. So the Sta-Bil sits in can for maybe 1 ~ 2 years.

 

[Hedges]

I'm 48 volts on one system, 96 on another.

48 volts for homes, cabins, common shop, 96 for the big crap in the shop.

The reason for 48/96 is cells.
I build 48v batteries, just series them for the 96v system. The 3 phase industral inverter won't run on less than 96 volts.

Do you put a bypass diode across each 48V battery?
If lithium with BMS, I'm not sure it could take the 96V or so one would see when the other disconnects. (Or are you using a contactor?)

What inverter is that?

 

[EastTexCowboy]

I only use non ethanol gas. I consider additives such as Pri G as a waste of good money. The only gas additive that actually worked was lead. For diesel you do need an anti-algae additive for long storage periods and a way to separate water.

Consumer gas additives often contain ethanol. Seems like a bad idea to buy ethanol free gas and end up adding it. It does serve a purpose as a dryer* as it allows moisture in the gas to be suspended in solution for safer combustion.

* Most gas dryers are wood alcohol or methanol instead of ethanol.

I get non ethanol when I can but it's hard to find anywhere close. I don't use enough gas to bother with the additive but I do use quite a bit of diesel. The distributor I have now puts in an additive before they deliver the fuel but before that I used Pri D. Not for any performance reasons but purely to stabilize and extend the life. I still have several bottles around and the shelf life is at least 10 years if it's unopened.

There were some military studies done (I'd have to look for the info but it's out there if you search) and Pri D surpassed Stabil and all the rest by quite a bit. Not only did it extend the usable life of diesel but they added it to diesel that was several years old and it "restored" it enough that it was perfectly fine for use.

Prior to Pri D I had used Stabil in lawnmower gas and boats and it did more harm that good. The equipment ran rough and had fuel system issues so much I stopped using it.

Or I could just buy an old deuce and a half with the Hercules engine and run anything in it. I actually thought about it but I can't see it worth the hassle and expense. I'd rather put that money into something solar. I keep looking at electric side by sides but I don't think they are there yet.

 

[EastTexCowboy]

I ran into a problem with stabil. I have been running it in about everything since I have like 40 vehicles and mowers and tractors etc to try to keep gas from going bad. The problem first showed up in my riding mowers. Its a gummy residue that clogs up the fuel bowl and the jets. I'm not sure if its happening in the larger vehicles but I had nothing but problems with that mower forming the crap and besides gas the stabil is all I used in it. Makes me a bit leery of the stuff now. Its been forming in weed eaters I have too.

I don't use additives in my diesels which I know can form algae from what Ive read but Ive never had an issue with the diesel stuff. I have one truck that has had the same fuel in its tank for 8 years or more now. I just move it around the yard to mow the grass so I've never run the fuel out enough to fill it in a bit

I had similar issues with Stabil. Not so with Pri G but I mostly use Pri D in diesel. The algae is a separate issue but my distributor puts now puts in anti-algae and a stabilizer before they deliver it. I have a 500 gal tank and I think for some reason a larger volume seems to hold up better. That's just anecdotal with no science to back it up.

 

[JeepHammer]

Diodes rectify, but have a voltage drop. Don't care much with generator or grid power.
For inverters and SMPS, usually a MOSFET is used in place of or in parallel with diode, for lower voltage drop (just a resistance) and less loss.

PV cells of course are a diode, but application is quite different. They are forward biased in the sun, and Voc is the voltage where conduction through the diode equals current production (no current flows to load.)

I didn't get into it, but I used the term 'Isolator'... A generic term that gets the point across.

YOU seem educated,
You and I are aware of this issue, and heat, resistance, impedance, inductance, etc...

This was a guy being introduced to a completely new subject, so I went easy on the technical jargon, alternatives, options, etc.

HE went and looked up diodes, isolators.
HIS education begins one step at a time. I don't want to overload that...
It's a steep learning curve, everyone takes it one step at a time...

Some people learn hands on, some are text book learners. I don't want to overload and burn out anyone starting out, and the lessons you learn by solving problems stick with you the longest.

I've seen electrical engineers that don't fully understand the electro-magnetic link, or have worked in their specific field so long they don't remember reluctance or inductance works more than one way...
(The books changed after they got out of school, then they did the same job for so long they don't connect the dots anymore)

No shade on them, they got THEIR job done and done well for may years, it's just frustrating to be told I can't be doing what I'm doing even though its been up and running for 30 years...
Getting you education updated by arguing on the internet isn't that efficient and is annoying to anyone watching.

This guy was just interested in getting different batteries to work together, string charging & isolation is a simple way to do that without creating other issues.
I'm proof, it's so simple even I figured it out! ?

I have a friend, PhD in EE that builds control systems for power plants...
It's nothing for him to design the circuits, circuit boards, everything custom. Of course he makes close to $650/hr to $6,000/hr for what is IN his head, has $50,000 design programs on his computer, etc.

I'm NOT that guy! I'm a disabled military farmer/metal worker with busted knuckles, so what he can do is FM (freaking magic) to me, I can't even begin to keep up with him.

He LOVES fishing, I have a private lake, river dock, he loves home cooking, we can/jar and cook country meals, he gets really tired of the rat race, we have quiet cabins right between the lake and river...

The information he has given me off hand, right off the top of his head has saved me $100s of thousands of dollars since he can specify exactly what inverters, transformers, etc I need and provide engineering specs/designs over a home cooked meal on my patio.

He can have all the pork steak, creek fries and fish he can hold, anytime he wants!
Hell, I'd give him a cabin if he wanted it full time!
He's also able to locate surplus/used equipment that meets his specs in minutes, all I have to do is write the check...

If I can pass along ANY information that might help, I'm willing. If it doesn't fit your specs/application, then it didn't cost you anything.

 

[JeepHammer]

Do you put a bypass diode across each 48V battery?

No.
Series batteries don't need a diode.
Diodes/Isolators only need to be between batteries and Buss.

The LESS resiatance/voltage drop you have between series batteries the better off you will be.

DC current seeks the other end of it's opposite polarity.

For instance, if you have a 24 or 48 volt industal battery, you can count the cells (6 in series) and connect a 12 volt charger to those 6 cells.

Where the first 6 and the second 6 connect, you will have the positive from one charger AND the negative from another charger connected at the same place.

Two DIFFERENT chargers, two different DC circuits, the two will ignore each other since they only 'Seek' (complete a circuit) with it's polar opposite.

When it was difficult to find above a 12 volt charger, I charged big industal 24, 36 & 48 volt batteries with 12 volt chargers this way.

The main positive & negative of the battery were still 24, 36 or 48 volts, but each connected charger had its own CIRCUIT through the 6 cells it was connected through, INSIDE of the larger circuit of all cells in series.

The one hitch, all the 12 volt chargers had to run together or the cells got WAY out of balance.

The early Lithium batteries I got were 12 volts, but had plugs to series them together. You could charge each one with 12 volt charger, the charge controller in each battery took care of the cells in that battery,
OR,
You could charge the entire string based on the series voltage.
The BMS in each battery communicated through the plugs, switched voltage for what the charge source was (12, 24, 36, 48 volts)

If lithium with BMS, I'm not sure it could take the 96V or so one would see when the other disconnects. (Or are you using a contactor?)

BIG ASS CONTACTORS! IN PARALLEL.
Several thousand amp capacity.
The big industral inverter is a transformer type, and just charging the transformer will draw several hundred amps even when the inverter isn't powering anything.

Since it's a transformer, it has high losses when not being used, it's only charged when we run high voltage 3 phase equipment.

What inverter is that?

Delta, one of the better brands from China. Like I said, it's an industral unit, capable of 220/440 volts, true 3 phase.
Not like we use it all day, but it was cheaper to do 96 volts/inverter than to custom order the existing production machines it powers.

As a side note...
Contactors/relays can be used two ways.
Most people use them, power them up to connect a load to power.

You can also use them always connected to something that's always 'On'.
This means some additional losses, but for a purpose...

If something goes WRONG, your safety circuit can cut the power and the contactor/relay will OPEN, the failure 'Fails Safe', full shutdown. Airgap open circuit that can't reconnect without manual reset.

This is where you ask the question to the supplier about 'Duty Cycle'.
If it's not 100%, full time duty cycle rated, then you are going to change a lot of relays/contactors until you figure this out.
(Yup! Leaned that the hard way too)

The duty cycle is why I parallel some of them. All of them will eventually give up, but parallel you aren't trying to find the issue in the dark, the second, redundant takes over and you find the fault on routine inspection/maintiance.

Again, there is more than one way to skin this cat...

 

[Mattb4]

I get non ethanol when I can but it's hard to find anywhere close. I don't use enough gas to bother with the additive but I do use quite a bit of diesel. ....

Luckily there are several Stations that carry non ethanol gas in my area. With driving my 2000 model 1-ton truck once a month at most, and it having 40 gal tanks, the gas in it sits for a long time before being cycled. My Honda generator mostly sits these days and though the gas might be still good after a year I prefer to drain and replace it. It is usually less than a gallon so not a big cost.

I also use a fair amount of diesel in my tractor and skid steer loader though not as much as I went through in the past. I have never had problems with diesel storage but I do add a bit of algaecide every year.

 

[Hedges]

No.
Series batteries don't need a diode.
Diodes/Isolators only need to be between batteries and Buss.

Bypass diode is my proposal when connecting lithium batteries with MOSFET based BMS in series.
Only some 12V BMS support series connecting to 48V. If one BMS opens, it sees -48V across it. Adding a diode would clamp that to about 12V.
Same if someone connected server rack batteries in series.

The LESS resiatance/voltage drop you have between series batteries the better off you will be.

Since I was proposing a bypass diode, zero current flow. It is reverse biased 12V (or 48V) when system is operating.

For instance, if you have a 24 or 48 volt industal battery, you can count the cells (6 in series) and connect a 12 volt charger to those 6 cells.

So lead-acid, no BMS disconnecting. Therefore my diode suggestion isn't applicable.

BIG ASS CONTACTORS! IN PARALLEL.
Several thousand amp capacity.

So long as contactor can take the voltage, and opens if any BMS in series wants to open, that also solves the problem.

The big industral inverter is a transformer type, and just charging the transformer will draw several hundred amps even when the inverter isn't powering anything.

Since it's a transformer, it has high losses when not being used, it's only charged when we run high voltage 3 phase equipment.

Delta, one of the better brands from China. Like I said, it's an industral unit, capable of 220/440 volts, true 3 phase.
Not like we use it all day, but it was cheaper to do 96 volts/inverter than to custom order the existing production machines it powers.

OK, understand what it is now.
I have 3x SI putting out 120/208Y. And I have VFD fed 240Vrms to power a 2HP pool pump.

Step-up transformer from 120/208Y to 277/480 for Sunny TriPower turned out to be a problematic load. I have some transformers which are reasonably well behaved.

 

[JeepHammer]

Luckily there are several Stations that carry non ethanol gas in my area. With driving my 2000 model 1-ton truck once a month at most, and it having 40 gal tanks, the gas in it sits for a long time before being cycled. My Honda generator mostly sits these days and though the gas might be still good after a year I prefer to drain and replace it. It is usually less than a gallon so not a big cost.

I also use a fair amount of diesel in my tractor and skid steer loader though not as much as I went through in the past. I have never had problems with diesel storage but I do add a bit of algaecide every year.

I won't get into what you 'Believe' about ethyl alcohol being added to gasoline...
Comminist plot, Alien technology, whatever, doesn't matter to me.

The reasons ethyl alcohol in specific (the same alcohol in your booze) was added to gasoline... (trigger alert: Facts headed your way)

To reduce tail pipe emissions.
Lots and lots of carburetor older cars on the road, alcohol was a way to reduce the harmful emissions, both solids and gasses.

To dry out fuel supplies.
The fuel supply chain had a LOT of moisture issues back then, which caused problems with O2 sensors, catalytic converters, etc.

Mandates on fuel storage has eliminated a bunch of these problems, but if you put fuel in a steel tank above ground where temps swing wildly, that tank is going to draw in moist air, the air IS going to shed the moisture in the tank... It's the physics of liquids, pure science.

Alcohol readily absorbs the moisture so it can go through the combustion process without creating other issues with emission and sensor equipment.

ALL liquid fuels exposed to atmosphere are going to vapor off, they are VOCs by definition. (Voltile Organic Compounds)
They WILL change form, break down and off gas, draw moisture, grow plant or animal life, etc. Absloute scientific fact.

As the bootlegges found out during prohibition (1920s, so the facts have been around 100 years) you can make MORE POWER from alcohol than gasoline.
Gasoline engines can't keep up with Alcohol cars at the drag strip, running plain gasoline in a super car will force the computer to de-rate the engine to keep it alive.

You want those big Horse Power numbers, get E-85 or alcohol racing fuel.
Cools the intake tract allowing for higher boost pressures without detonation problems in specific.

The ONLY thing lead does in car engines is lubricate IRON valve seats. Since we now have hardened STEEL valves and valve seats, no big deal to eliminate the widest human spread toxin in human history...

If you really must have lead, go to the airport and get aviation gasoline, it still has lead in it... (or just suck on tire weights)

 

[JeepHammer]

Thank you Mr jeep hammer much appreciated

I might be back with some pics when I start getting things together

I'm lazy, so I like looking at pictures! Beats doing any actual work! ?

 

[Hedges]

YOU seem educated,
You and I are aware of this issue, and heat, resistance, impedance, inductance, etc...

BS EECS UCB, MS EE SJSU.

When I designed microprocessors at HP, I only understood FETs like pinching a hose. I didn't get how bipolar worked, but I used them as a hobbyist.
Went back for MSEE during the great layoffs, this time I survived semiconductor device physics and understand transistors better. But not at the quantum mechanics level.

I've learned more about diodes on the job (reverse leakage of Schottky causing heating and thermal runaway.)

Recently (after 4 decades career) I've started learning more about transformers than just turns ratio. These things were used as amplifiers before transistors or vacuum tubes existed. I'm able to measure, model, SPICE the saturation and hysteresis characteristics. First I was just measuring performance; it was more difficult getting models that represented the behavior.

I have a friend, PhD in EE that builds control systems for power plants...
It's nothing for him to design the circuits, circuit boards, everything custom. Of course he makes close to $650/hr to $6,000/hr for what is IN his head, has $50,000 design programs on his computer, etc.

I'm NOT that guy! I'm a disabled military farmer/metal worker with busted knuckles, so what he can do is FM (freaking magic) to me, I can't even begin to keep up with him.

I split the difference, a fraction of his pay. But good enough to be comfortable, since I'm frugal (and a pack rat.)
I sometimes tell PhD's that they're wrong.

The information he has given me off hand, right off the top of his head has saved me $100s of thousands of dollars since he can specify exactly what inverters, transformers, etc I need and provide engineering specs/designs over a home cooked meal on my patio.

Transformers and inverters - I thought it would be so easy, just buy a 480 delta to 120/208Y step-down transformer and run it backwards. Didn't work out so well. Properly specified and built they would be fine, but typically commercially available transformers are operated too far into saturation and draw excessive current. To address that I feed 120V into 240V windings, and only drive primary not secondary.

transformer excitation current - isolation transformer used as auto-transformer

So you think you can backfeed a transformer secondary, either as step-up or as auto-transformer? Turns out these things aren't so ideal and reversible as one might expect. It isn't just the greater inrush (primary is often wound outside secondary to reduce inrush current), but also idle current...

diysolarforum.com

transformer excitation current - isolation transformer used as auto-transformer

So you think you can backfeed a transformer secondary, either as step-up or as auto-transformer? Turns out these things aren't so ideal and reversible as one might expect. It isn't just the greater inrush (primary is often wound outside secondary to reduce inrush current), but also idle current...

diysolarforum.com

 

[JeepHammer]

Bypass diode is my proposal when connecting lithium batteries with MOSFET based BMS in series.
Only some 12V BMS support series connecting to 48V. If one BMS opens, it sees -48V across it. Adding a diode would clamp that to about 12V.
Same if someone connected server rack batteries in series.



Since I was proposing a bypass diode, zero current flow. It is reverse biased 12V (or 48V) when system is operating.



So lead-acid, no BMS disconnecting. Therefore my diode suggestion isn't applicable.



So long as contactor can take the voltage, and opens if any BMS in series wants to open, that also solves the problem.



OK, understand what it is now.
I have 3x SI putting out 120/208Y. And I have VFD fed 240Vrms to power a 2HP pool pump.

Step-up transformer from 120/208Y to 277/480 for Sunny TriPower turned out to be a problematic load. I have some transformers which are reasonably well behaved.

Sorry Hedges, I mistaked you post for the guy wanting to Buss different batteries...

The early Lithium batteries I got could be series plugged in together, the BMS communications were in the plugs.

VERY propritary design, but it would auto-sense the charge voltage and switch appropriately.

There is a reason I usually take cells and connect a BMS I understand to them when I salvage cells...

I made ALL the mistakes, even made a couple new ones...

Small cells in Parallel, then series. The BMS can't monitor individual cells in parallel, so problems with salvaged cells.

With the low cost of BMS units now, and a big increase in big Amp hour cells (close to 300 Ah) I just look for big cells to start with and let the BMS monitor/manage them.

The one thing that chaps my butt on even the good/capable BMS units is no real cell balancing yet.
I usually slap a capable cell balancer on with the BMS, and my imbalance shutdowns have dropped to nearly zero.

Why they can't put a 5 Amp balancer in the BMS is beyond me, but they won't and 100mA to 250mA just doesn't cut the mustard when talking constantly used 300 (+/-) Ah cells.
If the auto makers can do it, why can't we buy one on the open market?

 

[Crowz]

I won't get into what you 'Believe' about ethyl alcohol being added to gasoline...
Comminist plot, Alien technology, whatever, doesn't matter to me.

The reasons ethyl alcohol in specific (the same alcohol in your booze) was added to gasoline... (trigger alert: Facts headed your way)

To reduce tail pipe emissions.
Lots and lots of carburetor older cars on the road, alcohol was a way to reduce the harmful emissions, both solids and gasses.

To dry out fuel supplies.
The fuel supply chain had a LOT of moisture issues back then, which caused problems with O2 sensors, catalytic converters, etc.

Mandates on fuel storage has eliminated a bunch of these problems, but if you put fuel in a steel tank above ground where temps swing wildly, that tank is going to draw in moist air, the air IS going to shed the moisture in the tank... It's the physics of liquids, pure science.

Alcohol readily absorbs the moisture so it can go through the combustion process without creating other issues with emission and sensor equipment.

ALL liquid fuels exposed to atmosphere are going to vapor off, they are VOCs by definition. (Voltile Organic Compounds)
They WILL change form, break down and off gas, draw moisture, grow plant or animal life, etc. Absloute scientific fact.

As the bootlegges found out during prohibition (1920s, so the facts have been around 100 years) you can make MORE POWER from alcohol than gasoline.
Gasoline engines can't keep up with Alcohol cars at the drag strip, running plain gasoline in a super car will force the computer to de-rate the engine to keep it alive.

You want those big Horse Power numbers, get E-85 or alcohol racing fuel.
Cools the intake tract allowing for higher boost pressures without detonation problems in specific.

The ONLY thing lead does in car engines is lubricate IRON valve seats. Since we now have hardened STEEL valves and valve seats, no big deal to eliminate the widest human spread toxin in human history...

If you really must have lead, go to the airport and get aviation gasoline, it still has lead in it... (or just suck on tire weights)

When they started adding corn squeeze to gas I personally had all kinds of issues not to mention that stuff STINKS to high heavens when it sits for a few months. When your dealing with tons of the stuff sitting around in various vehicles you get tons of field data on its effects.

All vehicles run like CRAP when the stuff goes bad after a few months. Skipping, spitting and sputtering till fresh gas in put back in.

All of the exhaust coming out smells like sewer pipes.

It EATS weedeater carbs alive if not redone with a modern kit and even those don't last very long. I'm so glad I'm all electric on yard tools now.

I used to never have issues with gas sitting in a vehicle for a year or two before this evil plague.

 

[Hedges]

Mandates on fuel storage has eliminated a bunch of these problems, but if you put fuel in a steel tank above ground where temps swing wildly, that tank is going to draw in moist air, the air IS going to shed the moisture in the tank... It's the physics of liquids, pure science.

As I found in the mountains, with the perfect temperature swing and fog. My gas tank would extract several ounces of water from the air.
Solution is a tank like cars usually have, vacuum breaker but pressure seal. That prevents breathing. I also used a portable boat tank, manual seal.

The ONLY thing lead does in car engines is lubricate IRON valve seats. Since we now have hardened STEEL valves and valve seats, no big deal to eliminate the widest human spread toxin in human history...

One other thing lead did was boost octane. For a while, rumor was that filling 50/50 with leaded and unleaded gave additional octane boost.
There are alternative additives now (molybdenum?) Instead-O-Lead Gold lists manganese.

https://www.bardahl.nl/assets/uploads/2017/12/Instead-of-Lead-GOLD-1.pdf

It EATS weedeater carbs alive if not redone with a modern kit and even those don't last very long. I'm so glad I'm all electric on yard tools now.

I used to never have issues with gas sitting in a vehicle for a year or two before this evil plague.

For small equipment, I do turn off gas valve and run carburetor dry.