I'm installing a new system for a van build. Trying to do a full charge of the battery, but it seems the charging gets "stuck" (battery voltage varies ~0.1 up and down) after ~5 minutes or so. The charger stays in bulk mode. I've turned it on and off a couple of times and changed some settings, without any success.
Things I'm trying to understand:
- First of all, what can be wrong?
- Additionally:
- How can there be a high charge current, but a battery that isn't charging? Is it bad for the battery or charger to leave this on?
- Is this decrease in cell voltage normal?
- Does the setting "charged voltage" in the smartshunt have any effect on the charging process, and is 13.2 correct for a lithium battery?
What happened
Initially, the battery was 13.1v. Did a charge with the standard lithium setting. The battery got to 13.42, and stopped charging. Then went to inverter mode. The next day turned the system back on, and it went to charging in bulk again. First started noticing cell voltages didn't increase. Additionally, the battery voltage seemed too low (should go up to 14.2 right?), so I started tweaking the settings and turning the system off and on in the hope to solve it.
What I'm noticing each time:
- Before turning it back on, the cell voltage has dropped back to ~3,34 (there are no loads connected to the system)
- I turn the system on, first minutes seem well, voltage is steadily increasing, the charger doesn't make a lot of noise yet, status is bulk mode
- After ~5 minutes the charger starts making more noise, and the battery voltage goes ~0.02 beyond the last highest voltage and then stays there.
- After ~20-30 minutes, battery voltage seem the be fluctuating 0.01 increase/decrease in battery cells, still bulk charging
- I check the charge current and voltage through the smartshunt. Voltage is 0.5 higher than battery, charge current at max 35a. The battery temp is normal (around 30 degrees Celcius)
Here are some screenshots from the battery status during one of the tests:
Components currently installed:
- Victron Smart Litium battery 330 Ah, updated to last firmware
- Victron SmartShunt, updated to last firmware
- Victron Multiplus 800/12/35, updated to last firmware
- Victron VE.bus bms
- Victron Gerbo GX
Some system images (wiring diagram at the end of page):
Settings
Battery
Smartshunt
Multiplus
Wiring diagram