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New PowerMax Lithium Series Converter/Chargers

Op,

Can you please enlighten us on the logic which this fine charger uses to STOP charging?
When does it stop charging and what indication does it give to the end user that it has stopped charging?

When the battery voltage reaches the charge voltage setting on the charge source, the current stops flowing.
It does not give an indication, it just stops charging. The Victron Orion works the same way - whatever you set the charge voltage at it charges till it reaches that, reducing current flow as it reaches full voltage. I tested that out when I got it all hooked up, it's very cool. My solar charge controllers also work this way - wherever you set the charge voltage it will pass current 'till that level is reached, reducing current as it gets close. If the battery is full - full voltage - they quit charging, go into float.

This tells me that setting an appropriate charge voltage is key. I would have preferred that the PowerMax 2-stage charging mode voltage could be adjusted - this appears to not be the case. However you can set the fixed voltage output where it acts as a simple power supply, and it will charge full amps until the voltage comes up on the battery, then it reduces current and stops. I just wouldn't float a lifepo at 14.4 volts or whatever, anything higher than 13.6, 13.4 preferred.

It sure charges the pack up fast though - I really like that. If my cells get low off grid and I don't get solar charging, I can start the generator - now on the chassis batteries, and run the converter/charger and put 55 amps in till I get it to where I want it. A couple of hours charging would add a lot of amps in my case, with a 230A pack.

These units also get used as a power supply - you don't even need a battery for 12 volt loads. This is why they are installed in RV's - so you can plug in and operate your 12V system, even without a battery.

As I explained in testing, it's easy to see what it's doing with the BMS app. And I put the unit on a watt-meter so I could see what it was doing on the AC side.

Powermax enjoys a reasonably good reputation, Graham is very responsive, and seems committed to earning market-share with their product line. Product support is there, good warranty coverage, and they sell tons of these things. I'm not a shill for them, I bought the unit with my own money. I also considered Progressive Dynamics and IOTA as well - I had one of the latter installed for over a dozen years in this motorhome. This is about the new unit from them, seems to do what it's advertised to do - good support for lifepo4 batteries.

Your posts seems condescending. Perhaps you didn't intend to be. If not, fine, if you are please stop it. I am simply sharing what my findings are on this power supply. Polite discussion and learning is what we're all about here on the forum.

I've never heard of the brand you mentioned, perhaps they're a good alternative.

EDIT: The link you provided is for a 6A charger. That simply wouldn't do what I need in my RV.
 
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When the battery voltage reaches the charge voltage setting on the charge source, the current stops flowing.
It does not give an indication, it just stops charging. The Victron Orion works the same way - whatever you set the charge voltage at it charges till it reaches that, reducing current flow as it reaches full voltage. I tested that out when I got it all hooked up, it's very cool. My solar charge controllers also work this way - wherever you set the charge voltage it will pass current 'till that level is reached, reducing current as it gets close. If the battery is full - full voltage - they quit charging, go into float.

This tells me that setting an appropriate charge voltage is key. I would have preferred that the PowerMax 2-stage charging mode voltage could be adjusted - this appears to not be the case. However you can set the fixed voltage output where it acts as a simple power supply, and it will charge full amps until the voltage comes up on the battery, then it reduces current and stops. I just wouldn't float a lifepo at 14.4 volts or whatever, anything higher than 13.6, 13.4 preferred.

It sure charges the pack up fast though - I really like that. If my cells get low off grid and I don't get solar charging, I can start the generator - now on the chassis batteries, and run the converter/charger and put 55 amps in till I get it to where I want it. A couple of hours charging would add a lot of amps in my case, with a 230A pack.

These units also get used as a power supply - you don't even need a battery for 12 volt loads. This is why they are installed in RV's - so you can plug in and operate your 12V system, even without a battery.

As I explained in testing, it's easy to see what it's doing with the BMS app. And I put the unit on a watt-meter so I could see what it was doing on the AC side.

Powermax enjoys a reasonably good reputation, Graham is very responsive, and seems committed to earning market-share with their product line. Product support is there, good warranty coverage, and they sell tons of these things. I'm not a shill for them, I bought the unit with my own money. I also considered Progressive Dynamics and IOTA as well - I had one of the latter installed for over a dozen years in this motorhome. This is about the new unit from them, seems to do what it's advertised to do - good support for lifepo4 batteries.

Your posts seems condescending. Perhaps you didn't intend to be. If not, fine, if you are please stop it. I am simply sharing what my findings are on this power supply. Polite discussion and learning is what we're all about here on the forum.

I've never heard of the brand you mentioned, perhaps they're a good alternative.

EDIT: The link you provided is for a 6A charger. That simply wouldn't do what I need in my RV.

Op,
I am on your side, I hate for you get burnt and learn the same lesson we have.

1. #9 in owner's manual clearly states that PowerMax remains in TRICKLE mode for ever, ever, ever [insert rap song]

My apologies if I came out strong. But happiness comes from a predictable system, which will shutoff when charging is complete.

So, if I had to pick between 2 charges, I would pick the one which shuts OFF when charging is done.

Meanwell has chargers for nearly all current ranges you need. Meanwell is the NOT only charger in town now, I just bought a 80v charger from Luna Cycles. Pricey but I wanted to support them for a fine product they carry.

I have a 60a charger for 280ah 48v system, I plan on using EV charge stations to rezap my LFE on my way down south.

pb-1000-12
will give you mucho amps,

On the bright side, you should be sponsored by PowerMax, they should send you a box of cannolis as appreciation.

Look up a users called DrBass on endlesssphere, he is the meanwell gawd, if you interested.
 
Op,
I am on your side, I hate for you get burnt and learn the same lesson we have.

1. #9 in owner's manual clearly states that PowerMax remains in TRICKLE mode for ever, ever, ever [insert rap song]

My apologies if I came out strong. But happiness comes from a predictable system, which will shutoff when charging is complete.

So, if I had to pick between 2 charges, I would pick the one which shuts OFF when charging is done.

Meanwell has chargers for nearly all current ranges you need. Meanwell is the NOT only charger in town now, I just bought a 80v charger from Luna Cycles. Pricey but I wanted to support them for a fine product they carry.

I have a 60a charger for 280ah 48v system, I plan on using EV charge stations to rezap my LFE on my way down south.

pb-1000-12
will give you mucho amps,

On the bright side, you should be sponsored by PowerMax, they should send you a box of cannolis as appreciation.

Look up a users called DrBass on endlesssphere, he is the meanwell gawd, if you interested.
The Powermax does do charge termination its the details of the timer based algorithm that are preposterous.
30 minutes boost
11.5 hours "bulk/absorb" at a significantly lower voltage
then float at an even lower voltage until the unit is power cycled, it never goes back into the first 2 phases.
The boost is so short its not really useful.
The bulk/absorb is generally too long and has no tail current based termination.
Having your battery sit exposed to charge voltage above full resting for hours is an un-necessary stressor.
 
Powermax may well continue to trickle-charge - I did not get that far in testing. I never worried about this before, FLA's like to be kept peaked up.

For lifepo I don't want it sitting on any kind of charge if it's fully charged, so I put the Powermax on a switched outlet. I guess I'll need some real time usage to make a final determination, but my intention for it is to use it when charging is actually needed. Turning off all loads to the pack also lets it rest at a mid-point SOC when the rig is parked. I used to leave it plugged in with the IOTA and FLA's, but don't find a need to plug it in now.

In testing the Orion with the same 13.4 charge voltage, engine running, it would put out about 12A until the battery voltage got close to the 13.4 - it got down to 1A when I shut it down.

I did not let the Powermax reach full charge voltage on the battery, but it also tapered down from about 12A to 5-6, with the cells sitting at about 3.35 volts. I will further test with both modes - see if they quit passing current once the pack reaches full charge voltage. lllll

I can't speak to the boost mode duration - I would want to test that with a less than nearly fully-charged battery. I didn't get any where near 30 minutes, it was more like 3-4 minutes. With no load it switches charge voltage in a few seconds.

Graham claims the new unit has a 4 hour boost or absorption duration, or until the battery reaches full charge voltage. He seems to understand what users want, but then I have no idea his level of expertise in lifepo charging. I'm not even sure he has much technical knowledge on the units - he couldn't tell me what the VR2 pot was for - one would think he would have a schematic or design layout for the product he sells. Perhaps he's just buying an off-the-shelf Chinese product developed from some knock-off China engineers. [shrug]

I did previously print out the 'How Charging Works' PDF and referred to it for my voltage settings. It has good specs and parameters.
So far I like the fixed-output mode - good fast charging with genset to reach a satisfactory SOC off grid. Turn it off when not needed.

I wouldn't call any of these charging methods very 'smart'. I think you still have to monitor them to keep them all working together. I think Victron does a better job of integrating everything.
 
Jimmy, bro, cancel your order and/or refuse delivery, whatever you can SEND IT BACK and get your money back pls.

There is NO 2 switchable voltages, ALL LIES,
All there is ONE pot which raises initial voltage and float voltage by the SAME amount.

One word "Deception",

See Op's own desc, this NOT how a true 2 stage charge behaves, you can put lipstick on a Powermax but it is still a dumb Powermax



Please take sometime and read what a true 2 stage charge does and how it should behave, also see you can set the charge CURRENT and VOLTAGE

Thanks for the warning. This is the PM4 60A 4-stage charger that I bought. Not the PM3 Lithium Series.
I know it doesn't give 2 selectable voltages out of the box. Just a switch to select 4-stage or fixed voltage. And there's a pot for voltage adjustment in fixed voltage mode.
I mean to remove the pot from the board and with some measurement and testing, build a board that wires into the pot location to allow me to set 2 different voltages and select between them with a switch. So I can select a higher voltage like 14.3 or 14.4 for fully charging and balancing the cells or a lower voltage like 13.6 for long floating them.
 
Thanks for the warning. This is the PM4 60A 4-stage charger that I bought. Not the PM3 Lithium Series.
I know it doesn't give 2 selectable voltages out of the box. Just a switch to select 4-stage or fixed voltage. And there's a pot for voltage adjustment in fixed voltage mode.
I mean to remove the pot from the board and with some measurement and testing, build a board that wires into the pot location to allow me to set 2 different voltages and select between them with a switch. So I can select a higher voltage like 14.3 or 14.4 for fully charging and balancing the cells or a lower voltage like 13.6 for long floating them.
I suggest you put it in fixed voltage mode and set the voltage to a nice safe float voltage of <=3.35 volts per cell.
That'll give you better than ~80% reserve capacity.
Then let your solar charger top off the batteries as necessary.
 
I suggest you put it in fixed voltage mode and set the voltage to a nice safe float voltage of <=3.35 volts per cell.
That'll give you better than ~80% reserve capacity.
Then let your solar charger top off the batteries as necessary.

That's what I did with the Orion - 13.5 fixed voltage, or 3.375 per cell. That way I don't have to worry about it when driving, regardless of what else is going on. It will charge the house pack to full without overcharging it. Is 13.4V a safer setting?

For the powermax, I set fixed at 14.4 for quick charging. I'll shut the unit off when either the current drops, or I have enough juice for that session. Roof top PV's should keep it up pretty well. I can also isolate the house lifepo pack and run the house loads with the converter along when plugged in at an RV park or something. I'm hoping we'll now be able to do a lot more dry-camping, off grid, boondocking. Whatever you want to call it. :giggle:

I suspect the Powermax 2-stage 14.6/13.6 is designed for folks to set it and forget it - with their RV plugged in. It's going to rest their lifepo batteries at a high state of charge without over charging them. If it never shuts off and keeps feeding current at 13.6 then it will tend to overcharge them, no???

The problem with the 4-stage unit is that it does a high-voltage 'equalization' charge at intervals - can't recall if that is every 7 days (I think so) or 28 days like IOTA does.

BTW, the IOTA IQ dongle for their DSL units that is supposed to configure it for lifepo, has the same 2-stage charging, but their resting or 'float' voltage is 13.8. Many claim that is too high for lifepo4 cells.

Modifying the control board would not be an option for me. Surely I would screw that up. LOL
 
That's what I did with the Orion - 13.5 fixed voltage, or 3.375 per cell. That way I don't have to worry about it when driving, regardless of what else is going on. It will charge the house pack to full without overcharging it. Is 13.4V a safer setting?
13.5 is probably fine.
13.4 is 3.35 per cell and is according to a well respected, knowledgable and experienced member of the forum is the float voltage used in lifepo4 UPSs.
Also Andy from @Off-Grid-Garage did some tests and shows a cell will not get overcharged at 3.35 volts/
3.65 is full
3.45 is considered the lowest slowest full charge voltage.
3.35 is my maximum preferred float voltage.
Each is a 100mv increment and I like round numbers.
For the powermax, I set fixed at 14.4 for quick charging. I'll shut the unit off when either the current drops, or I have enough juice for that session.
Where possible I prefer to engineer human error out of the system.
I suspect the Powermax 2-stage 14.6/13.6 is designed for folks to set it and forget it - with their RV plugged in. It's going to rest their lifepo batteries at a high state of charge without over charging them. If it never shuts off and keeps feeding current at 13.6 then it will tend to overcharge them, no???

The problem with the 4-stage unit is that it does a high-voltage 'equalization' charge at intervals - can't recall if that is every 7 days (I think so) or 28 days like IOTA does.

BTW, the IOTA IQ dongle for their DSL units that is supposed to configure it for lifepo, has the same 2-stage charging, but their resting or 'float' voltage is 13.8. Many claim that is too high for lifepo4 cells.
I'm on my 3rd Powermax and my first IOTA.
The IOTA is much better in multiple ways.
The IOTA LFP dongle should work fine and if memory serves it even has relatively sane charge termination.
The cheap loopback dongle that comes free with the units is also good.
IMO...
IOTA is a pretty good converter.
Progressive dynamics and IOTA are teir 1
WFCO is teir2.
Powermax is bottom of the pile.

That being said converter's are a sunset product.
If you want a decent ac2dc charger get a mid level or higher inverter/charger.
 
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That being said converter's are a sunset product.
If you want a decent ac2dc charger get a mid level or higher inverter/charger.

Makes sense. I wasn't doubting the voltage recommendations.

What makes the powermax chargers bottom of the pile? In what way do they fail?
I'm curious now...if they're so bad why did you buy two more of them?? LOL

I was hoping to make this work because I inquired multiple times here about the best way to charge lifepo in the RV and didn't get any replies. Solar was the best way. Mostly I got that everything was old design meant for FLA's and didn't work so well with lifepo4. Initially my idea was to simply install a AC charger with a lifepo charging profile. A decent high-amp charger is rather expensive.

No one could tell me whether I really needed a converter or not - I didn't think I did, but elsewhere on the interwebs people have posted that RV's must have a converter. So when I found this new model it made sense, was a decent price, and my hope was that it was a good solution.

What is an example of a mid level or higher inverter/charger? I've already spent a couple of grand on this upgrade, and I already have an inverter - a Xantrex PROwatt SW with remote.
 
What makes the powermax chargers bottom of the pile?
Power factor correction is poor.
The higher capacity units are not ul-listed.
The 50amp@24 volt unit I have has a nema 5-15 plug and gets hot to the point the plastic on the plug gets soft and squishy.
Which is probably why they are not ul-listed.
IOTA has a nema 5-20 plug on its 40 amp unit and is ul-listed.
The fans are very loud.
They don't put out there rated power.
My 30 amp unit delivered ~25 amps.
My 50 amp unit delivered ~45 amps.
For comparison my IOTA is rated at 25 and delivers ~27 amps and its fan is not nearly as loud.
In what way do they fail?
My first unit's output dropped from ~25 amps to ~15 amps after ~50 charge cycles.
I'm curious now...if they're so bad why did you buy two more of them?? LOL
The 2nd one was a replacement for my first one was DOA.
The 3rd one still works but I won't leave it to run autonamously because the plug gets uncomfortably hot.
I was hoping to make this work because I inquired multiple times here about the best way to charge lifepo in the RV and didn't get any replies.
I thought I did.
A decent high-amp charger is rather expensive.
DIY solar is a harsh mistress.
No one could tell me whether I really needed a converter or not
I thought I did.
What is an example of a mid level or higher inverter/charger?
Xantrex freedom or Kisae bic https://www.kisaepower.com/bic-launch/
 
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Here is an interesting view of the market.
The Xantrex freedom and cotek inverter ~1000watt untits are darn close in price to the Samlex.
The Samlex is a tier1 beast.
The Xantrex is a high frequency unit and there have been reports that the ac connectors are fragile.
Its also not nearly as configurable.
No doubt in my mind that I would choose the Samlex.
 
How 'bout a Samlex 12V charger?

I just need a 120-12v charging source for shorepower and generator. It runs when I plug in or start the generator.

Would that work for me? Would I be happy with it?
 
How 'bout a Samlex 12V charger?

I just need a 120-12v charging source for shorepower and generator. It runs when I plug in or start the generator.

Would that work for me? Would I be happy with it?
Its probably ok but I think this one is a better choice.
The current is configurable it works for both 12 and 24 volts and I am confident that this vendor will go the extra mile.
Not knocking https://www.donrowe.com but the chief bottle washer for https://www.currentconnected.com helps people here on the list and that means something.
 
FYI:
I charge my batts with max possible time in CC mode,
Only the 75a size?
Says it draws 9A at rated output.
What is the max amps of the Orion unit you have?

For electric charging what is the max amps you are needing?
 
The orion is a 18A. I was going to skip it, but thought it might be handy driving at night or for rainy days.
I don’t really have a target. Our max daily is about 80-100Ah if the furnace runs. I have 600w of solar panels - 430 flat on the roof and 160 portable.

I would like to be able to charge ebike packs, they are 2-4 A for 3-4 hours. About 12Ah each from the house.

All lighting is led, 60w led tv, charge laptop and iphones.

The biggest draw is the furnace, about 10A, unless the 600w inverter is running something.

Cooking heating and hot water are all LPG - 20gl. 100gl each of water and holding tanks, 75 gasoline - 8.1L V8. Yes, it gets 8mpg regardless. Lol We tow a chevy spark or Colorado 4x4 - got one of each, and a boat, and 2 eMTB’s. Obviously not everything at once. Lol
 
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Tonight I tested the inverter output to run the pack down some and try fixed-output charging with the Powermax. Later I'll try the same test and use the 2-stage charging and see what it does. I reset the fixed output to 13.55V.

I tried running a new ceramic portable heater I just got, shows 4.3A on low setting on the watt meter, but the inverter would not run it. My heat gun on low setting showed about 3A and that runs fine, pulls about 45A on the pack. With the lights on and the furnace running I was pulling 55A. Ran it for about 15 minutes, battery dropped down to 13.0V showing 73% capacity. One concern is the watt-meter showed 99V on the inverter receptacle - must be voltage drop, but from inverter to outlet? That extension is a 14A power cord, tested the two, one is about 6' and the other about 10'. I did not check the AC out on the inverter as it's buried under the fridge.

Switched off the loads and turned on the charger and it was putting out 30A to the battery. Over the next two hours it gradually dropped it's current as the pack voltage rose. After a couple of hours it was at 98% and still charging at about 5A. After four hours it showed 100% and charging 2A, 13.45V on the pack. I turned on a few lights and started the furnace to see how it would respond - bms showed discharging 10A and then gradually dropped off and charging started to show on the plus side till it was charging about 10A. Shut off the load, it gradually dropped back down. I got tired and left it connected with the converter running - will check it overnight.

For being plugged into shorepower this seems ideal for bringing the battery to full charge and maintaining it at the chosen charge voltage you set.
It's slow - but it brings up equilibrium gradually and maintains that voltage level on the pack.

When I screen-captured four hours later it was still charging at 37W. Cells are at a 4milivolt delta:

 
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Oh, and at these lower amperages the fan is very quiet. It's under the sofa, I laid down on it for a time to simulate sleeping, and my tinnitus is louder than the charger. LOL. It does have an odd ring tone to it, not like other cooling fans I have experience with. It's hard to explain. Anyway, it's very quiet, but audible when it runs if there's silence. It would come on for 5 or ten minutes then shut off for five or ten.

Was a nice relaxing time. ?
 
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