question

justinr avatar image
justinr asked

Ideal maximum SOC when optimised with battery life - 100% or 97%?

Hi - I had an issue a couple of days ago that this community helped me resolve - thanks again @Alexandra ! (https://community.victronenergy.com/questions/223199/vrm-completely-wrong-soc-battery-reading-interferi.html)

Now everything is back to normal, EXCEPT that previously the system stopped charging the battery once it was reading 96% - 98%. The installer told me that was normal and necessary to maintain battery health/life. ESS has always been, and continues to be, set to 'optimised with battery life'.

However, after implementing the fix to my previous issue (see link), it is now charging all the way to 100%. Should I be happy about that, or is it something to fix?

Thank you!


ESSSOC
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seb71 avatar image
seb71 answered ·

Should I be happy about that, or is it something to fix?

Don't worry, be happy.

SOC is relative, voltage is more important and the BMS should keep that in check. There is not much voltage difference between 96%-98%-100% SOC.

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But, do you have a particular reason for using "Optimized with Battery Life"?

That is better suited for Lead-Acid batteries (which must be fully charged daily if possible).

For LiFePO4, in my opinion "Optimized without Battery Life" is the better choice.

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mikaeel avatar image mikaeel commented ·

lead acid should be fully charged daily? is that true? ive read something that once a week or two weeks it should be charged to 100%. in between it can be at 80% for example. is that wrong?

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seb71 avatar image seb71 mikaeel commented ·

That's the goal of "Optimized with Battery Life": to fully charge the battery each day.

(I am talking about normal charging, not about equalization.)

If fully charge was not achieved during that day, it will raise the Minimum SOC. For more details about how this works, read the ESS manuals.

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mikaeel avatar image mikaeel seb71 commented ·

Thanks. I have. The weird thing is: even if i have activated "Optimized with Battery Life" and the min SoC set to 80%, even after two weeks it never fully charges my batteries automaticly to 100% on cloudy days if solar is not sufficient. So i added "planned charging for 9 Hours to 100% SoC" every third day.

Is that normal that it doesnt automaticly charges Batteries to 100% and is my planed charging a good idea or will it overcharge my FLA Batteries?

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seb71 avatar image seb71 mikaeel commented ·

it never fully charges my batteries automaticly to 100% on cloudy days if solar is not sufficient

Increase the PV array size (add more PV panels and maybe more/bigger MPPTs - depending on what you have) or decrease your energy consumption.

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mikaeel avatar image mikaeel seb71 commented ·
ok, that would be one solution.


i thought "optimized with Battery Life" charges the batterys up from the Grid on some point if it sees that no solar power is comming (weather forecast), doesnt it?

Greetings

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seb71 avatar image seb71 mikaeel commented ·

"Keep batteries charged" ESS option would also charge from the grid.

But that is not the best choice if you actually want to make use of as much as posible energy from the Sun.

More suited when you want to use your system as an UPS (for power grid blackouts).


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nickdb avatar image nickdb ♦♦ mikaeel commented ·
No, it raises the minimum discharge soc every time it doesn’t fully charge.
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mikaeel avatar image mikaeel nickdb ♦♦ commented ·
sadly it didnt raise the 80% at all in two weeks. just stayed there.
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