A reluctant LiFePo4 convert...

[John61CT]

Well literal 12V is not the average voltage over the whole discharge cycle.

Best to use Ah as the canonical unit, Wh does not really accurately reflect the cells' internal chemical processes.

But even using 13V the outcome is a healthy pack, right?

[TimC]

Well literal 12V is not the average voltage over the whole discharge cycle.

Best to use Ah as the canonical unit, Wh does not really accurately reflect the cells' internal chemical processes.

But even using 13V the outcome is a healthy pack, right?

Yup, 114 aHr at 13v. I'm happy

[saltydawg]

I agree when I do the math I use 13 volts, just to be a little more accurate. When I do solar stuff I use 14 volts, ie a a 100 watt panel at 14 volts would give 7.14 amps if everything was perfect.

Basically if a load I use 13, if a charge I use 14. That is when I remember to think about it.

[TimC]

I talked to a representative at Noco today and asked him about charging with the 7200 (7.2a). I wanted to know if the Noco was capable of charging to around 80% instead of 100%. He said if I disconnect the charger when the 75% LED is steady and the 100% LED is slowly flashing i should be able to get close to 80%.

I'm also looking at several LiFePo4 charts and if I average them out I should shoot for a charging voltage of 13.9v for 80% charge.

This only applies to charging with the Noco. Foe solar charging I still have to do some research on the Epever's MT50 remote meter capability. I'm pretty green on the meaning of all the parameters for that charge controller.

I'm ok with Noco's explanation as I'll rarely charge with the Noco and instead rely on the solar charge controller to take care of most of my needs.

[John61CT]

Yes in fact 13.8V for 4S is plenty.

How full you get depends how long you hold at that voltage - CV stage or Absorb - it is easy to get to 100% Full in just a short time.

If you are not holding CV at all, then going higher V and stopping also gets you to a bit higher capacity utilization

even stopping at 14V or higher

and you will still not be stressing the pack at all, good for longevity.

However even more important than your stop-charge point is only charging just before you are starting the discharge cycle.

Do not let the pack just sit at high SoC% if possible.

[John61CT]

An hour after charging, resting isolated, 4S LFP anywhere above 13.2V is as Full as you ever need to get normal cycling.

Higher than 13.4V shows you went higher enough to be stressful, not a big deal, but not ideal for longevity.

[flboy]

Tim,

Do you have an Epever solar controller? I am assuming so since you mentioned the MT50. In any case, they work well for LiFePo4 if you program it properly. Battleborn has the settings you would need on thier website. I am using those settings and solar is charging well.



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[TimC]

Tim,
Do you have an Epever solar controller? I am assuming so since you mentioned the MT50. In any case, they work well for LiFePo4 if you program it properly. Battleborn has the settings you would need on thier website. I am using those settings and solar is charging well.
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Yes, I have the Epever Tracer 3210AN and the MT50. I watched Will P's video on optimizing the Epever for Battleborn. I basically followed his description of what to change. I don't know what Will means by optimization. I'm guessing it's for extended life of the battery, but, I think he is mostly concerned with off-grid home/cabin use which might not match my needs of occasional 25-30 aHr per day draw and most of the time no load while it sits patiently waiting for me to travel.

The Epever manual has all the setting for LiFePo4. I haven't compared that to Will's suggestions.

https://www.youtube.com/watch?v=-aBlHfgFjNc