Best charging voltage for 16S lifepo4 EVE cell battery?

[Lorax_UK]

Hi,

I'm at the point of ordering a charger for a 16S EVE 304Ah battery, and I can specify the charging voltage that I want.
I have read all kinds of figures online, and on this site, but they don't seem to give me a definitive answer.

I'm keen to prioritise longevity of the cells.

In this case, would 56V be a sensible choice?
I'll be using an active balancing BMS, so maybe this makes a difference? (negating the need to get to a higher voltage/S.O.C in order to balance?)

Many thanks in advance.

 

[DaLanMan]

There is no documentation on charge voltage?

That is weird. Do you know what the cels are?

I mean you could just go with charge it at 2amps knowing it would not fail on you.

You could be wild and pull the trigger on 4, with it most likely won't fail... Or you need to either ask the vendor or Manufacturer. Some of em will die before giving up their source on what they are using. Because they are lying through their teeth..

I had a great chat with a vendor claiming she was selling Tesla cels...

 

[Lorax_UK]

Sorry, I should have added some more info.
The Cells are EVE LF304K, specifications below:

• Manufacturer: EVE
• Grade: A
• Model: LF304K
• Size: 204mm x 174mm x 72mm
• Capacity: 304Ah
• Weight: 5.49KG
• Maximum Discharge: 304A (1C)
• Nominal Voltage: 3.2V
• Cycle Life : 3500 cycles @ 0.5C

I know they can be charged at a max voltage of 3.65 per cell, meaning in theory 58.4V
But I'm sure that you have the option if giving the cells an easy life by reducing this voltage down, and you actually sacrifice very little capacity (1% or something silly) in doing so.

56V would mean 3.5V per cell, does that sound like a good idea?

The charger I'm looking at is 25A (about 1400W).

 

[999zip999]

There is no need to go past 3.5volts. what 304 ah battery this is for a solar unit. Even 3.45v is a good target as there is very little power stored above that.Here is a Little info.

https://batteryhookup.com/products/4-new-eve-3-2v-280ah-lk280k-lifepo4-prismatic

 

[Lorax_UK]

Perfect, many thanks. I'll go ahead and order with 56V charging voltage.

 

[999zip999]

Lorax what are you using it for ?
Lifepo4 is a very forgiving chemistry you have choose. I had very high quality Lifepo4 cells that could that 3.8v with little harm. Not suggested. A lot of cheap and other BMS that target 3.65v then bleed down.
But I can tell you 3.45v if you can adjust balance on BMS is top. As some brands like to settle at 3.40v. As at that voltage they will slow voltage drop under load. But 304ah there is a large capacity difference in a large cell at same voltage 3.40v
Again what are you doing with this ? Meaning what kind of demands are you going to make on this pack of batteries ? No need to got below 2.9 volts.

 

[Chalo]

I charge LiFePO4 batteries at 3.5V/cell, because that's relatively gentle for them and because there's diddly squat worth of energy above that level. But almost all the pedicabbers around these parts charge their 16S LiFePO4 packs at 58.X volts without apparent issues.

 

[Lorax_UK]

Great stuff, thanks for the info.
I am converting a Polaris Ranger UTV from ICE to electric. Using 48v is maybe a bit low in terms of an EV, but I'm going to give it a go and see how it works.
If I can get away with running as low as 48v, it will work well with my plan to put an inverter onboard, meaning I have a good 240v AC supply anywhere on our farm,