Is this a safe choice for a LiFePO4 charger?

[wired1]

PowerMax PM3-55-LK > 55 Amp 12 Volt Converter / Charger

Hi Guys, I could really use some help choosing here. I'm looking to buy something tonight that won't hurt my 200 AH 12 volt Ampere Time batteries.

Can I leave this connected overnight or all day when I'm out?

https://powermaxconverters.com/wp-content/uploads/2018/05/PM3-12V-LK-Manual-2018.pdf

 

[chrisski]

I’d start with the Max amperage the batteries can be charged at. .

My FLA batteries of that size can be charged around 39 amps for 200 ah, so the 55 ah would be too much

Each battery chemistry is different. Lithium’s if 200 ah may be fine at 55 amos

 

[wired1]

I’d start with the Max amperage the batteries can be charged at. .

My FLA batteries of that size can be charged around 39 amps for 200 ah, so the 55 ah would be too much

Each battery chemistry is different. Lithium’s if 200 ah may be fine at 55 amos

Thank you! Someone told me in another post to keep the charge rate under 50 amps, preferably 40! I think I was confusing adjustable volts with amps.....I thought this was good because you could adjust the charge voltage, not thinking of the amps... I am wondering if the same charger in the 45 amp model would be ok? I'm very concerned with not damaging the batteries. Kind of like a new Ferrari

 

[John Frum]

PowerMax PM3-55-LK > 55 Amp 12 Volt Converter / Charger

Hi Guys, I could really use some help choosing here. I'm looking to buy something tonight that won't hurt my 200 AH 12 volt Ampere Time batteries.

Can I leave this connected overnight or all day when I'm out?

https://powermaxconverters.com/wp-content/uploads/2018/05/PM3-12V-LK-Manual-2018.pdf

You mention batteries as in plural.
How many do you have?
A good minimum charge rate for lifepo4 is .2c.
For 1x 200ah battery that is 40 amps.
If you charge at a lower rate, you may not get enough head to get into the high knee and constant voltage before the batteries are full.
That makes it easy to over charge them.
Also Powermax are the cheapest chargers out there and are not UL listed.
I used to be a fan, keyword is used.

 

[Substrate]

That's a lead-acid based 3 stage charger. I would NOT.

If you are going to go this route, look into an IOTA charger that does NOT have an internal IQ4 module.

Then, get a dedicated IQ4 module designed for LFP with it:

IQ4 LIFEPO Smart Charge Controller - 2-Stage Smart Charge Controller for the IOTA DLS to Use With Lithium-Ion Batteries With BMS

The IQ4 LIFEPO is tailored for use with today’s state-of-the-art LiFePO4 batteries that use a Battery Management System. The IQ-LIFEPO allows the DLS to deliver proper voltage to charge the larger

www.iotaengineering.com

Or more simply, since LFP has a very low state of discharge, just keep it disconnected when not in use, and not at 100% full charge, and look in on it once in awhile.

 

[wired1]

I have 2 batteries 200 ah each. I couldn't wrap my head around the right all in one to buy so because time is short, ( I need this to work next week), I've decided to use a 12 V Inverter that I have and just buy a charger for now. I was going to wire them for 24 V, but I ran out of learning time, so 12 volts it is for now. These batteries have a 100 ah BMS also.

 

[wired1]

That's a lead-acid based 3 stage charger. I would NOT.

If you are going to go this route, look into an IOTA charger that does NOT have an internal IQ4 module.

Then, get a dedicated IQ4 module designed for LFP with it:

IQ4 LIFEPO Smart Charge Controller - 2-Stage Smart Charge Controller for the IOTA DLS to Use With Lithium-Ion Batteries With BMS

The IQ4 LIFEPO is tailored for use with today’s state-of-the-art LiFePO4 batteries that use a Battery Management System. The IQ-LIFEPO allows the DLS to deliver proper voltage to charge the larger

www.iotaengineering.com

Or more simply, since LFP has a very low state of discharge, just keep it disconnected when not in use, and not at 100% full charge, and look in on it once in awhile.

OK, can you tell me where I can get one of them in a hurry and perhaps one that would be proper?

I am in panic mode now as once I get there on Tuesday, I'm on a remote Island for months where the power goes out at least weekly and sometimes for days.

 

[time2roll]

I like the PM3. The top voltage is adjustable as you know, the absorption time is fairly short (15-30 min?), the regular voltage is 13.6 and should be fine, the float mode after a couple days at 13.2 should be good long term or just unplug. To my knowledge the starting boost charge does not self reset periodically like the PM4 models.

Not sure IOTA really hits the voltage you want.

Worst case you can get a controller that will cut power to the converter when your top programmed voltage is hit. Then connects power when the low voltage setting is reached. This may even work for your existing converter regardless of make or programming.

 

[John Frum]

I have 2 batteries 200 ah each. I couldn't wrap my head around the right all in one to buy so because time is short, ( I need this to work next week), I've decided to use a 12 V Inverter that I have and just buy a charger for now. I was going to wire them for 24 V, but I ran out of learning time, so 12 volts it is for now. These batteries have a 100 ah BMS also.

.2c for 2x 200ah batteries in parallel is 80 amps.
The IOTA voltage is adjustable(have to remove the cover) and comes with a boost pendant.
The 75 amp model has a nema5-20 plug on it though.
It should come from the factory set to 13.6 volts and 14.2 volts with the boost pendant inserted.

IOTA DLS-75, 12 Volt, 75 Amp Converter/Charger | DonRowe.com

The IOTA DLS-75 converts 12 volts AC to 13.4 volts DC for both DC load operation and 12 volt battery charging up to 75 amps. UL Listed.

www.donrowe.com

 

[chrisski]

Here’s a good discussion on the Iota Chargers.

IOTA Engineering IQ4 LiFePO4 Module Discussion

There have been concerns posted on the forum about the charge profile used by the IOTA Engineering IQ4 LiFePO4 module. This is a plug-in module used in their DLS series converters that come in different amp ratings as well as different volt ratings. I sent questions to their Tech Support group...

diysolarforum.com

Way I summarize: THere is no ideal way to charge a Lithium Battery using a RV COnverter, but some chargers are better than others.

 

[Substrate]

That was a great thread. I think I learned something and talked about it there.

But for here - I might not use the IOTA as my house "desktop" charger, but save it for use with a genny.

 

[wired1]

Can any of you suggest any type of 12V charger that I could get in the next 2 days to take on my trip that would work well for these batteries? I don't need it to be a converter, just a charger that will safely charge these batteries in 8 hours or so? (I'm thinking from a plave locally like Walmart, Orielly's, Auto Zone, Best buy, etc...) Thanks again for your help, I do appreciate the time you all give to helping us w/o the knowledge...

 

[chrisski]

This is the charger I bought that Trojan support recommended for two of their 6 volt golf cart batteries hooked up in series for a total of 12 volts and 228 amps:

Amazon.com: NOCO Genius G26000 12V/24V 26 Amp Pro-Series Battery Charger and Maintainer: Automotive

Buy NOCO Genius G26000 12V/24V 26 Amp Pro-Series Battery Charger and Maintainer: Battery Chargers - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

Its a 26 amp charger with FLA, AGM, and LIthium modes. I have flooded lead acid batteries. I also know I had a hard time finding a charger that delivered large amperage to batteries consistently. Many chargeres advertised something like a ”30 amp boost mode,” but only delivered that for 5 to 30 minutes, much less than these large batteries needed. For my 228 ah of batteries this is perfect and will reach 100% indicated on the charger. When I hook 4 batteries up for 456 ah total, it never reaches 100% on its built in indicator, but hydrometer measurements show charging at 95% to 100%.

 

[wired1]

This is the charger I bought that Trojan support recommended for two of their 6 volt golf cart batteries hooked up in series for a total of 12 volts and 228 amps:

Amazon.com: NOCO Genius G26000 12V/24V 26 Amp Pro-Series Battery Charger and Maintainer: Automotive

Buy NOCO Genius G26000 12V/24V 26 Amp Pro-Series Battery Charger and Maintainer: Battery Chargers - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

Its a 26 amp charger with FLA, AGM, and LIthium modes. I have flooded lead acid batteries. I also know I had a hard time finding a charger that delivered large amperage to batteries consistently. Many chargeres advertised something like a ”30 amp boost mode,” but only delivered that for 5 to 30 minutes, much less than these large batteries needed. For my 228 ah of batteries this is perfect and will reach 100% indicated on the charger. When I hook 4 batteries up for 456 ah total, it never reaches 100% on its built in indicator, but hydrometer measurements show charging at 95% to 100%.

Do you also use this for LiFePO4 batteries?

 

[chrisski]

I don’t use this for lithium’s. I don’t have them. THe charger does have a lithium mode.

I spent a lot of time trying to find high amperage chargers you plug in the wall, and this was about it. I do recommend you contact the battery manufacturer tech department to see if this will work or what they recommend.

I really think you’re in uncharted waters looking for a plug in, clip on high amperage charger for lithium batteries. Not many people doing that.

 

[wired1]

I don’t use this for lithium’s. I don’t have them. THe charger does have a lithium mode.

I spent a lot of time trying to find high amperage chargers you plug in the wall, and this was about it. I do recommend you contact the battery manufacturer tech department to see if this will work or what they recommend.

I really think you’re in uncharted waters looking for a plug in, clip on high amperage charger for lithium batteries. Not many people doing that.

Thank you again. What I'm looking for is to re charge my 2 200ah LiFePO4 batteries in around 8 hours if they are down say to 20%. Not sure how to determine that? Will this do that?

 

[chrisski]

It claims 26 amp hours, so in 8 hours it will provide a little over 200 ah of charging, so this would fall short of the 320 ah you are asking for in an 8 hour period. If you want more charging than 26 amps or 30 amps, the only thing I found were RV chargers. You are asking for about a 40 amp charger.

 

[wired1]

It claims 26 amp hours, so in 8 hours it will provide a little over 200 ah of charging, so this would fall short of the 320 ah you are asking for in an 8 hour period. If you want more charging than 26 amps or 30 amps, the only thing I found were RV chargers. You are asking for about a 40 amp charger.

Thanks again for your help with this. I am going to get whatever charger I can find this weekend that will work and not cause damage. Ideally it would be 40 amps, but I could live with a smaller unit or even 2 separate chargers. The thing I'm trying to achieve in the short term is running my Honda I2200 generator as little as possible to recharge these batteries in a grid down situation. This cottage is in the Bahamas and we often have grid issues weekly and some lasting for many days at times. I am working there for the next couple of months and getting shipments is like a slow boat from China, seriously!

 

[John Frum]

Thank you again. What I'm looking for is to re charge my 2 200ah LiFePO4 batteries in around 8 hours if they are down say to 20%. Not sure how to determine that? Will this do that?

An inverter/charger would probably have been much simpler.

 

[wired1]

An inverter/charger would probably have been much simpler.

Thanks, I hear you. It's just I ran out of time and filtering through all of the input could've taken months more which I didn't have. Ended up buying this after I sifted through all of the comments. I'm pretty sure it'll do the job for now, if it's even needed. Maybe the grid is prefect there now

Progressive Dynamics PD9145ALV 12V Lithium Ion Battery Converter/Charger - 45 Amp​