I have a smart lithium battery and 100/30 mppt, 500 wott pannle and dc to dc charger. My. Mppt also gose off bulk charge and moves to asbestos / float before my battery even reaches 50% is there reason why? [IMG_9083] [IMG_9084] [IMG_9085] ▶ Summary

Your MPPT is getting up to the absorption voltage of 14.2V. As your battery is not getting to 100% I expect that you have a high resistance connection between your battery and the MPPT due to the cables being too long or too thin or having a loose connection or you are using the cheap no name therma…

These are the cheap no name breakers. [breaker2] [breaker1]

The SOC on the Fogstar BMS is not the best. It ignores currents under 1.5amps so I’m my case with only a 130w panel there is often a charge going in that just doesn’t register. Similarly my system has a quiescent current of 0.56amps which never registers. That’s 13.5Ah a day it never sees. As I ha…

Thanks guys that really helpful give me somewhere to go and look and have an investigation

Sorry for slow reply but of update I’ve got the one and done fuses type in photo and got the multimeter out the MPPT side is showing a higher voltage than the battery side still can’t work out why after and checking al my cables [IMG_9752]

When charging what voltages do you get on the MPPT terminals and battery terminals. Set your voltmeter to a lower range, say 0-2V and put the + lead on the MPPT + battery terminal and the other lead on the battery + terminal to see the voltage drop along the + wiring. Then move the + lead from the M…

Smart lithium not charging to 100%

DIY

pwfarnell 22 July 2025 18:05 3

These are the cheap no name breakers.

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Smart lithium not charging to 100%

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