Battery Voltage set to 14.35 but Smart Solar 100/20 is charging with up to 14.9V!!!???

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senna1976 asked Apr 4, '22

Battery Voltage set to 14.35 but Smart Solar 100/20 is charging with up to 14.9V!!!???

Hi Ladies & Gents,

today I realised that my SmartSolar is charging my battery with up to 14.9V even if I have set the limit to 14.35. It worked very accurate since I installed the SmartSolar 100/20. At the moment I'm testing the charger before I connect Li-Ion batteries to it to make sure I stay away from the Voltage limits of the batteries for safety reasons. But having more then 0.5V overvoltage during charging worries me quite a lot! What could be the reason for that and how can I get this under control?

battery charging charger overvoltage

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Answer 1 · 2022-04-04T15:36:11Z

Alexandra answered · Apr 04, 2022 at 03:36 PM

@senna1976

Temperature compensation?

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senna1976 commented · Apr 04, 2022 at 03:57 PM

Hi Alexandra,

could be. So I guess the value I set (i. e. 13.5V) is probably @ 20°C. My compensation I haven't touched and it is -16.2mV/°C. Does it mean when the temp goes down I increase the voltage?

For example: @ 10°C results then in in a 162mV higher chargin voltage (13,662V)

And ultimately if I don't want to increase the charging voltage I set the compensation to 0?

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kevgermany ♦♦ senna1976 commented · Apr 04, 2022 at 06:19 PM

25C, not 20C.

But this is for lead batteries. With lithium it should be zero.

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senna1976 commented · Apr 04, 2022 at 04:09 PM

I guess you're right. The last few days were pretty cold compared to the previous one. I just found the topic in the manual.

Thanks for the hint.

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