question

coaltrain1 avatar image
coaltrain1 asked

BVM700 not showing full charge.

Hi. I have a BVM700 connected to 4x155ah deep cycle gel batteries in parallel So (620ah at 12v) My battery charger, when connected floats at 13.7v. I have set the total AH to 620, set the tail to 1% and the time to 1 minute but cannot get the monitor to indicate 100% fully charged. What am I doing wrong?

battery charging
2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

1 Answer
Mark avatar image
Mark answered ·

For the BMV to 'sync' to 100% SOC the following 2 criteria must be met simultaneously and sustained for the 'charged detection time'

- Charged voltage

- Tail current

You did not mention what you have set the 'charged voltage' to but if it's a non solar application the recommendation is to set it a little under the float voltage. For solar systems it's normally set a little under the absorption voltage.

Having the 'tail current' set to 1% is very agressive and may make it difficult to sync. The default is 4% and I use ~2%.

Your 'charged detection time' of 1 min is the opposite, very relaxed and may cause premiture synchronizations if charging with solar. I would increase it to 2 to 4 min.

Remember it will only synchronise at the end of a full charge cycle when the battery charge current has significantly dropped off.

2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.