Growatt charger timeout in float mode


New Member
May 2, 2022
I am using Growatt SPF 5000 ES with 4 deep cycle LA batteries used in UPS mode.
After monitoring the system, i am sure the inverter is powered by the batteries even in the presence of utility. Any load priority Utility first or SBU or SUB manifesting the same unstable charger after charging the batteries to 100%.
The problem which is for Growatt not an issue, is after half hour in float mode, the inverter is draining and charging the battery as long as utility is available.

According to Growatt this is normal, but what happening is that batteries performance is weaker when experiencing fluctuation compared to the case without fluctuation.

I am not willing to install another string of batteries in parallel to decrease their impedance, but for sure this is not normal.

Any expert has a solution for this issue?


  • Growatt charger.jpg
    Growatt charger.jpg
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What are settings #12, #13, #19, and #20 set at?
setting 12: 51.2
setting 13: 58
Setting 19: 58.1
Setting 20: 54.8

I tried all options for settings 19 and 20. I tried 58.4 for bulk, 56V for float and also 54, 53, 55. Same behavior.
I am using Luminous battery C10, type LPPT 12200
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growatt inverter with the current software version not compatible with most of LA solar batteries.