Another Newbeee SHF system..

[Newbeee]

I'm building a SHF system, and plan to store long term, inactive, non connected still in the boxes in faradays, (until, if needed) for an off grid situation.
This will be used to run essentials like freezers lights, etc. Some loads like freezers will be on timers for load shedding.
This is my first build so un sure about a LOT of it: ( If you have thoughts please let me know).
After weeks of research aligning with a budget of $5k or so, I may be wearing out! LOL
So far I have these numbers
Sun=5.22
Peak 6705w
8,441 total watts per day
253 Kw per month
I already have these components,,
17 ea. 100w Siemens solar cells.
Victron MPPT 12/24 100/50 charge controller
1 ea. Victron batt. monitor
I think the LAST main pieces needed are storage and inverters.
I'm thinking of adding to complete this build ;
4 ea. 12 v 100 ah LifeP04 Ampere from Amazon? (Approx.) $400 ea. = 400 Ah
2 ea. Giandel 24v pure sign wave 4000w inverters (Approx.) $650 ea.
I would appreciate advise as to whether this will work as I think or if their is an issue that will prevent this from operating as needed above.
I will likely install and run for a short time to verify then store.
One of my questions are long term storage of the Batt? Can I just charge and ignore for months or years?
Originally tried to get Nickel Iron batteries but unsure about sending $ to china directly. And can not find a source in the us.
THANKS for any help!!!!

 

[Rednecktek]

4 ea. 12 v 100 ah LifeP04 Ampere from Amazon? (Approx.) $400 ea. = 400 Ah
2 ea. Giandel 24v pure sign wave 4000w inverters (Approx.) $650 ea.

I'm seeing a flaw in your math. If you do those 4 batteries in parallel you'll get 12v @ 400Ah, but you can't use the 24v inverter.
If you wire up those batteries for 2s2p you'll have 24v @ 200Ah

If you're going to be running a 24v system, what about the 24v 200Ah single unit batteries?

As for charging, what are the possibilities of getting a LiFe compatible PWM controller and snagging one of those 100w panels and just letting it keep the batteries topped up? It also makes math easier because trying to set up strings with an odd number of panels is a pain in the butt. With that controller your best bet would be a 4s/4p setup which leaves a panel sitting unused.

 

[MisterSandals]

I think Rednecktek has you covered with his sanity check of your numbers.

You will get a better understanding yourself if you make a little effort to understand the units of your numbers. When using the proper units (watt hours instead of watts for daily totals for example) a lot of the math is far more intuitive.

Sun=5.22
Peak 6705w
8,441 total watts per day
253 Kw per month

I don't know what some of this even is because it does not have units or has the wrong units.
5.22 hours of sun each day?
6705w ?? amount of solar panels? max power usage? I dunno. Peak ??
8441 total watts per day (watts is a rate, watt hours is an amount (100W for 5h = 500Wh)). So 8441Wh daily.
253kWh per month

Using the proper units, things like figuring out your solar panel needs are easy:
8441Wh / 5.22h = 1617W of solar panels (or implied by your numbers)

hope this helps

 

[MisterSandals]

This will be used to run essentials like freezers lights, etc. Some loads like freezers will be on timers for load shedding.

I meant to ask this in my previous post:
You are preparing for what sounds like an EMP event. Why do things like charge controllers and batteries need to be shielded yet freezers, lights, timers and solar panels do not?

 

[Rednecktek]

Why do things like charge controllers and batteries need to be shielded yet freezers, lights, timers and solar panels do not?

Actually I can answer that one. With the rare few exceptions, as long as a device isn't powered on when the EMP goes off, the EMP doesn't affect it. So in his case if the freezer and lights are turned off, they should have no problems powering up and running afterwards.

If something is required to be powered on to exist, like SCC's or inverters in standby mode, the EMP can damage the components, hence the shielding.
Now, I haven't looked into what happens to the panel itself, but my guess would be that because they are so passive they might survive just fine. Even more modern systems like the CPU in your car can take an EMP and will reset and run just fine once you disconnect and reconnect the power source.

 

[MisterSandals]

With the rare few exceptions, as long as a device isn't powered on when the EMP goes off, the EMP doesn't affect it.

So why the need to put electronics in faraday like enclosures, why not just unplug or leave in original packaging in the garage?

 

[Rednecktek]

That would be my first option, just pre-build everything for testing, then disconnect the batteries for EMP protection. About the only thing I can think of that you'd want in cages would be a SCC and the batteries just to keep the batteries topped up from a single panel while the fan is still clean.

BUT, having said that, much like other guy's smoke stack fan project, if that's the way you want to design the system, then that's the way you want the system designed. Sometimes the harder ways of doing things are the more fun and interesting ones.

 

[Newbeee]

Wow!! I already know more than before! Newbee for sure. Thanks ! This is the best place for info that their is!!
Good to know most EMP issues will be recoverable if the appliance or device is off.
Actually I think their are 2 likely scenarios. The EMP is one, and I know way more now than I did, Thanks!!
Another likely scenario may be a micro nova. And in that scenario I've heard, initially only faraday protected electronics will be spared but it also seems the out come in a particular reagon or area is any ones guess.
Does any one know more about micro nova type scenarios

I'm seeing a flaw in your math. If you do those 4 batteries in parallel you'll get 12v @ 400Ah, but you can't use the 24v inverter.
If you wire up those batteries for 2s2p you'll have 24v @ 200Ah

If you're going to be running a 24v system, what about the 24v 200Ah single unit batteries?

As for charging, what are the possibilities of getting a LiFe compatible PWM controller and snagging one of those 100w panels and just letting it keep the batteries topped up? It also makes math easier because trying to set up strings with an odd number of panels is a pain in the butt. With that controller your best bet would be a 4s/4p setup which leaves a panel sitting unused.

Great! Thank you all for the help!!!
So the better idea $, may be to go with the 4-12v 400ah and get the 12v inverter to get the needed 400 ah storage?
Is the main advantage of 24v smaller wire size to the inverter? 400 ah is 400 ah? Or am I missing more to the voltage/storage story?
Maybe the 2 ea, 24v/200ah has more storage justifying double the price as compared 4 ea,12v/100ah?

Another dumb storage question is, If I go with the 24v 200ah can I add another in a few months when $ becomes available and have or even continue to go to more storage capacity over time? Or with any LifeP04 bank can be added to?
I've heard that with Life P04 its not advisable to add more storage over time as the cells wont match correctly? Is it that critical?
Thanks!!

I'm seeing a flaw in your math. If you do those 4 batteries in parallel you'll get 12v @ 400Ah, but you can't use the 24v inverter.
If you wire up those batteries for 2s2p you'll have 24v @ 200Ah

If you're going to be running a 24v system, what about the 24v 200Ah single unit batteries?

As for charging, what are the possibilities of getting a LiFe compatible PWM controller and snagging one of those 100w panels and just letting it keep the batteries topped up? It also makes math easier because trying to set up strings with an odd number of panels is a pain in the butt. With that controller your best bet would be a 4s/4p setup which leaves a panel sitting unused.

 

[Rednecktek]

So the better idea $, may be to go with the 4-12v 400ah and get the 12v inverter to get the needed 400 ah storage?

A higher voltage system will make it easier to have larger inverters. The general rule of thumb is to keep your battery draw under 100a so:

100a @ 12v = ~1200-1500w
100a @ 24v =~2400-3000w
100a @ 48v =~4800-5000w

Many batteries don't like to have draws over 100a or so (as a generality) and it makes the wiring smaller and breakers/fuses smaller. At 100a a fuse will pop, but at 300a it's a flamethrower. Plus, many pre-built LiFe's have issues with draws over 100a and their BMS freaking out.

Now, depending on the loads you want to supply, rule of thumb again is 2x your expected load. So, if your power audit says you'll only ever need 948 watts, get a 2000w unit. 2200w? Get a 4000w unit. Sure, you'll probably never USE that much power, but startup loads and longevity make it always a good idea to give your system some head space.

Is the main advantage of 24v smaller wire size to the inverter? 400 ah is 400 ah? Or am I missing more to the voltage/storage story?

Maybe the 2 ea, 24v/200ah has more storage justifying double the price as compared 4 ea,12v/100ah?

This is where it comes to the watt hours calculation. Watts being Volts X Amp Hours = Watt Hours. So:
4x 100Ah @ 12v = 4800Ah
2x 200Ah @ 24v = 4800Wh
However, and this is where the math error came in:
2x 100Ah @ 12v in SERIES = 24v @ 100Ah = 2400Ah
4x 100Ah @ 12v in Series/Parallel = 4800Ah
Your original math was trying to get a 24v system AND 400Ah of power out of 12v batteries which would have been 9600Ah.

The bigger advantages of going to a single larger battery are 1: Lower complexity as you only have to wire in a single battery as opposed to balancing or serialing 2 batteries at a time, and 2: the cost of a 200Ah battery is often times just a bit lower than getting 2 100Ah batteries of the same brand/feature set. Some battery brands/models don't like to be put in serial, and some will only serial so far, so they might work in a 24v setup but not in a 48v setup. The single larger batteries also tend to support higher amperage draws than the smaller counterparts.

Another dumb storage question is, If I go with the 24v 200ah can I add another in a few months when $ becomes available and have or even continue to go to more storage capacity over time? Or with any LifeP04 bank can be added to?

That depends on the battery manufacturer but for the most part yes. Most LiFe's that I've seen here on the forums can parallel up nicely, but some have been known to have issues when putting in serial with other batteries. If you're wanting to future-proof, think about how you might want to connect the newer batteries in the future, something along the lines of a bus bar that each battery connects to and then feeds all the systems. The rackmount battery banks have become very popular not only for their low cost per watt hour but that they also play well with others and are physically easy to handle and stack.

When planning out the system, don't forget the tape measure! A dozen rackmount batteries and a 12Bazillion watt AIO inverter sound great on paper until you're sleeping on the kitchen floor because your bedroom is full of batteries.

 

[Rednecktek]

I've heard that with Life P04 its not advisable to add more storage over time as the cells wont match correctly? Is it that critical?

Not critical enough to sell a kidney for it. Best practice would to at least stick with the same make & model batteries if at all possible. The biggest issue with adding cells is more the DIY battery banks where having all the cells in a bank being as identical as possible is important and trying to find more of the exact same performing cells later is a real PITA.

 

[Bvillebob]

Being turned off doesn't protect electronics, especially modern devices. Most stuff these days is "always on", there's no mechanical switch or relay sepaating the input from the grid, just a semiconductor device that gets turned on or off. The only way to protect electroncs is to physically unplug it from the power grid. Even with a siwtch, the incredibly high pulses generated by. power lines can easily arc across the contacts. If you're worried about EMP, and even lightning nearby can cause huge EMP, unplug devices, don't just turn them off.

 

[Rednecktek]

Now, having said all that, let me re-iterate what has been said here many, many times:

Power audit, Power Audit, POWER AUDIT!!!

Before you spend a dime, do your power audit. Calculate out what you need, then add in what you want, then add in fudge factor. Buying ANYTHING before you've done this will waste money and cause frustration.

The power audit will tell you 3 major things you'll need to know:
1: How big does your inverter need to be?
2: How much battery bank will you need to feed it for 2-3 days?
3: How much solar panel will you need to recharge those batteries in a reasonable amount of time.

The Power Audit form available on here is pretty conservative and assumes the worst case scenario of everything running at the same time, so reality already adds in some fudge factor. I believe it also helps factor in efficiency losses as well. Doodle around with that for a bit and see what it comes up with.

Once you have all that, THEN start looking at the parts you'll need and throw it at us. We can help fine tune the system to your needs and budget and help figure out all the things you missed, because we ALL miss something the first time 'round.

 

[Samsonite801]

Now, having said all that, let me re-iterate what has been said here many, many times:

Power audit, Power Audit, POWER AUDIT!!!

Before you spend a dime, do your power audit. Calculate out what you need, then add in what you want, then add in fudge factor. Buying ANYTHING before you've done this will waste money and cause frustration.

The power audit will tell you 3 major things you'll need to know:
1: How big does your inverter need to be?
2: How much battery bank will you need to feed it for 2-3 days?
3: How much solar panel will you need to recharge those batteries in a reasonable amount of time.

The Power Audit form available on here is pretty conservative and assumes the worst case scenario of everything running at the same time, so reality already adds in some fudge factor. I believe it also helps factor in efficiency losses as well. Doodle around with that for a bit and see what it comes up with.

Once you have all that, THEN start looking at the parts you'll need and throw it at us. We can help fine tune the system to your needs and budget and help figure out all the things you missed, because we ALL miss something the first time 'round.

I agree with all of this, power audit is a great starting point. However, I always would stress to build a system that is scalable, which mainly to me means to incorporate an inverter model that is stackable (many brands can stack like up to 6), then say if you run out of PV input capacity, inverter output watts, things like that, you can just buy a 2nd one and a 3rd one, etc, it's easy to build all components out in parallel...

Then it doesn't have as much of a tendency to box a person into a corner if you take kind of a building block modular approach...

 

[12VoltInstalls]

most EMP issues will be recoverable if the appliance or device is off.

And not connected/plugged in to anything.
And maybe, maybe not because you don’t know what the energy of the event might be.

 

[Newbeee]

Wow great info!! I'm amazed and thank every one for the help!!! I will digest, and do a better audit.. AMAZING FORUM, you all ROCK! Thanks!

 

[Newbeee]

I meant to ask this in my previous post:
You are preparing for what sounds like an EMP event. Why do things like charge controllers and batteries need to be shielded yet freezers, lights, timers and solar panels do not?

Good question! I (have read) that setting static these will be fine if not wired to the grid. Panels are not mounted and are in storage. I also have freezers and fridges in storage in a grounded mettle shed. What do you think of the idea of no farada cage just not hooked to the grid as emp proof? ( sorry I missed your question before. )

 

[Newbeee]

I think Rednecktek has you covered with his sanity check of your numbers.

You will get a better understanding yourself if you make a little effort to understand the units of your numbers. When using the proper units (watt hours instead of watts for daily totals for example) a lot of the math is far more intuitive.


I don't know what some of this even is because it does not have units or has the wrong units.
5.22 hours of sun each day?
6705w ?? amount of solar panels? max power usage? I dunno. Peak ??
8441 total watts per day (watts is a rate, watt hours is an amount (100W for 5h = 500Wh)). So 8441Wh daily.
253kWh per month

Using the proper units, things like figuring out your solar panel needs are easy:
8441Wh / 5.22h = 1617W of solar panels (or implied by your numbers)

hope this helps

Mr Sandals I'm sorry I missed these reply's. My Forum ability seems lacking also. Sorry.
So you re saying (i think) my 1800 watts of panels will work for a 8441 Wh? So Storage seems to be the question. With the inverter
Thank you for the info.

I agree with all of this, power audit is a great starting point. However, I always would stress to build a system that is scalable, which mainly to me means to incorporate an inverter model that is stackable (many brands can stack like up to 6), then say if you run out of PV input capacity, inverter output watts, things like that, you can just buy a 2nd one and a 3rd one, etc, it's easy to build all components out in parallel...

Then it doesn't have as much of a tendency to box a person into a corner if you take kind of a building block modular approach...

Good question! I (have read) that setting static these will be fine if not wired to the grid. Panels are not mounted and are in storage. I also have freezers and fridges in storage in a grounded mettle shed. What do you think of the idea of no farada cage just not hooked to the grid as emp proof? ( sorry I missed your question before. )

I'm seeing a flaw in your math. If you do those 4 batteries in parallel you'll get 12v @ 400Ah, but you can't use the 24v inverter.
If you wire up those batteries for 2s2p you'll have 24v @ 200Ah

If you're going to be running a 24v system, what about the 24v 200Ah single unit batteries?

As for charging, what are the possibilities of getting a LiFe compatible PWM controller and snagging one of those 100w panels and just letting it keep the batteries topped up? It also makes math easier because trying to set up strings with an odd number of panels is a pain in the butt. With that controller your best bet would be a 4s/4p setup which leaves a panel sitting unused.

Using the proper units, things like figuring out your solar panel needs are easy:
8441Wh / 5.22h = 1617W of solar panels (or implied by your numbers)
Is corect! It is 12 volts though, does it matter if I want to use 24 v?

 

[MisterSandals]

It is 12 volts though, does it matter if I want to use 24 v?

What is 12V?

If you are wondering about what battery voltage is best, look at RedneckTec wrote in post #9. I think it depends on you max load which is likely your inverter but I have not reread to understand your needs/expectations from your system.

But if you think you want 24V system, by all means do it to make your amps (wiring and fusing) manageable.

 

[Samsonite801]

From my experience, 12v is only good up to about 2800-3000w, and you'll need 4/0 battery cable to make that possible (which is a bit spendy). I think it's realistic to use 12v on an RV where the user would like to use the native voltage and not switch everything to run on voltage converters...

My general rule for myself anyways, is if I need more than 3000w, I would skip 24v and just go straight to 48v operating voltage so I could future-proof the setup.

The only exceptions to that rule might be if I didn't have the budget to buy at least four 12v batteries, and only wanted two batteries. Or in the case of a friend of mine, his RV he has a diesel heater that runs on 24v natively, so he preferred to use 24v as his operating voltage because it made more sense for him to do that.

Other people here may as well have good reasons they prefer 24v for certain use cases, but I don't see too many reasons to not just consider jumping to 48v and get it over with. Then you can use the smallest sized cables, and make longer battery wire runs with less loss.

 

[12VoltInstalls]

does it matter if I want to use 24 v?

Not to the wattage requirements. That’s stable across voltage changes. 12V is useful sometimes but if you aren’t doing anything needing 12VDC 24VDC is better for midrange higher wattage.

The wiring and loads issues mentioned above are good and not worth rehashing