LifePo4 Charge Performance

[otrfun]

Thinking seriously about replacing our two GC2's with a pair of 100ah LifePo4's. Hearing a lot of chatter about how lithiums accept a charge much quicker than lead cells.

Very familiar with how our GC2's charge after being discharged to 50%. It typically takes our 45a converter 2.5 - 3.0 hours to charge them from 50% to ~90% (at 14.4v).

Assuming a pair of 100ah LifePo4's were discharged to say, 10-20%, roughly how long would it take a 45a converter to charge two 100ah LifePo4 batteries to 90-95% assuming the converter remained at 14.4v the entire time?

Thanks!

[RickLight]

Different brands can charge and discharge at different rates.

My 3 Lion Energy UT1300 can each discharge at 150A and charge at 100A but prefer 45A. I upgraded my charger to a lithium rated one and went to 75A. Even at 45A it's just over 2 hours from 0 to full.

The beauty is that the charging rate doesn't slow down as they fill, like all lead acid based. Their "internal resistance" is much lower so the last 10% is as fast as the rest.

[pianotuna]

An interesting web site that compares charging lead acid vs li.

Li apparently accepts a charge faster--but if the amp-hours are used up--they still have to be replaced. Most of the "big" inverter/chargers max out at some where over 115 to 125 amps. A bit lead acid bank can over load my inverter/charger forcing me to slow it down.

https://www.power-sonic.com/blog/how-to-charge-lithium-iron-phosphate-lifepo4-batteries/

[BFL13]

otrfun wrote:
Thinking seriously about replacing our two GC2's with a pair of 100ah LifePo4's. Hearing a lot of chatter about how lithiums accept a charge much quicker than lead cells.

Very familiar with how our GC2's charge after being discharged to 50%. It typically takes our 45a converter 2.5 - 3.0 hours to charge them from 50% to ~90% (at 14.4v).

Assuming a pair of 100ah LifePo4's were discharged to say, 10-20%, roughly how long would it take a 45a converter to charge two 100ah LifePo4 batteries to 90-95% assuming the converter remained at 14.4v the entire time?

Thanks!

An AH is an AH no matter what type of battery it is.

Using the mid points of your range, the 200AH of LFP charged from 15% to 93% would restore 156AH. At 45 amps, this would take 156/45 = 3.47 hrs, or 3 hrs 28 minutes.

Your GC2s at say 220AH in a 50-90 (40% = 88AH) with 45 amps initial charging rate should take about 2.6 hrs so your observation is correct.

If you need more AH per day than 88AH and doing a 50-90 each day, then there are other ways to get more AH, but it is all about scenario, RV set-up possibilities with your rig, and Money.