Challenge Fully Charging DIY Solar Generator

[nrivera56]

Hi all, new to posting after lurking for a couple months, thanks for your insights!

I have a challenge reaching full charge in my DIY mobile solar generator and not sure if it's my error or somethimg wrong with the system components. Here's the setup:

- 3 100W 12V Rockpals foldable panels in series
- Renogy Li Rover 40A charge controller
- 2 100Ah 12V Renogy LiFePo batteries in parallel
- 2000W Renogy inverter (pure sine)
- 2 bluetooth modules (one for charge controller and one for battery bank)

When charging the batteries in full sun, the charge percentages freeze at 89.00% and voltage readings at battery 13.23V and 13.31V at charge controller. When I leave it charging for another hours 4+ hours theres no change in the charge controller (no shift to float from bulk charging), no change in percentage, and really small change in battery voltage, 13.30 V.

I don't want to leave connected longer for fear of overcharging the batteries and degrading them. One time I left one 100W panel connected all day (through charge comtroller) to see what happened and the BMS gave a cell overvoltage protection error so I backed off for fear of hurting bank.

Another issue that arises is using the generator for watching movies on projector system (.1C discharge) is thinking I have more power than I do. Last night it went from 75% SOC to 50% after 2 hours, which seemed fine. But watching something for an additional 30 min after that (no change in discharge rate), it dropped to 9% SOC (12.7V).

With all this, these are my following questions:

• Should I leave the solar panels connected longer to see if anything changes past the 89% SOC?
• Should I ignore the battery SOC percentage from the bluetooth app and instead only look at the voltage readings? (I assume since it's talking directly to the battery BMS the SOC would be accurate)
• Why the sudden % drop on the battery read out?
• Is there something I'm not understanding?

Appreciate any insights and education on this area. Looking to increase my knowledge and do more with solar so this will be extremely helpful!

P.S. Attached some images for clarity

 

[MichaelK]

Is the charging voltage set at 13.2V, or is the charger putting out 13.2V. The battery documentation appears to expect to charge this battery with a voltage as high as 14.8V? Can you reconfirm that?

Your problem may be as simple as incorrect charge settings within your controller.

 

[Just John]

Hi all, new to posting after lurking for a couple months, thanks for your insights!

I have a challenge reaching full charge in my DIY mobile solar generator and not sure if it's my error or somethimg wrong with the system components. Here's the setup:

- 3 100W 12V Rockpals foldable panels in series
- Renogy Li Rover 40A charge controller
- 2 100Ah 12V Renogy LiFePo batteries in parallel
- 2000W Renogy inverter (pure sine)
- 2 bluetooth modules (one for charge controller and one for battery bank)

When charging the batteries in full sun, the charge percentages freeze at 89.00% and voltage readings at battery 13.23V and 13.31V at charge controller. When I leave it charging for another hours 4+ hours theres no change in the charge controller (no shift to float from bulk charging), no change in percentage, and really small change in battery voltage, 13.30 V.

I don't want to leave connected longer for fear of overcharging the batteries and degrading them. One time I left one 100W panel connected all day (through charge comtroller) to see what happened and the BMS gave a cell overvoltage protection error so I backed off for fear of hurting bank.

Another issue that arises is using the generator for watching movies on projector system (.1C discharge) is thinking I have more power than I do. Last night it went from 75% SOC to 50% after 2 hours, which seemed fine. But watching something for an additional 30 min after that (no change in discharge rate), it dropped to 9% SOC (12.7V).

With all this, these are my following questions:

• Should I leave the solar panels connected longer to see if anything changes past the 89% SOC?
• Should I ignore the battery SOC percentage from the bluetooth app and instead only look at the voltage readings? (I assume since it's talking directly to the battery BMS the SOC would be accurate)
• Why the sudden % drop on the battery read out?
• Is there something I'm not understanding?

Appreciate any insights and education on this area. Looking to increase my knowledge and do more with solar so this will be extremely helpful!

P.S. Attached some images for clarity

The 13.2v charge output is too low, you may wish to contact Renogy and ask why they set that value. Somewhere between 13.6 and 14.6 would be a better voltage.

 

[nrivera56]

Thanks for the feedback!

The SCC is set to Li charge mode but I was concerned that it wasn't charging high enough. I tried to adjust the settings to User input values to 14.4V, but when charging it stays the same, only charging at a little higher than the current voltage.

Is the SCC supposed to stay the same voltage level while charging?

Planning to contact Renogy as well!