Hi All,
Over the weekend I decommissioned a custom solar project that was using power divider, Arduino and Raspberry Pi and replaced it was my other Victron MPPT 75/10 which was used in the back shed that I swapped over the weekend with a 75/15 and using same solar panel 500w Trina.
The 75/10 has a 125w solar panel charging a 2x 40ah battery hooked in parallel at 12v. The 75/10 was originally doing 24v at 1.2kwh battery setup and now it's doing 12v at 0.96kwh.
The thing I'm seeing in HomeAssistant is the battery voltage is reaching 16.2v and when it was disconnected yesterday I hooked a multi metre to check both batteries and both were equal 13.1v each when they had no charge going into them.
The instantaneous power draw is 0.400a, Solar panel has 16mm cable fig 8 and each battery has 16mm Fig 8 cable so is my panel too weak? (Yes power cable is overkill but it was $1.50 each per metre from 5mm)
Panel rating
Peak power: 125 W
Short circuit current: 6.81A
Open circuit voltage: 24.05 V
Voltage at max power: 20.00 V
Current max power: 6.42 A
Thanks
Daniel
