New Battery Losing Charge

[LiquidLunch]

Hi,

Yesterday I fitted a new 120ah leisure battery in the van I ensured that the control panel was changed to reflect a different sized battery to the one previously fitted. I have a 100w solar panel with a Victron MPPT controller and a battery master. When I fitted the battery according to the control panel it was reading 13.6v. I have today fitted a Victron Direct Bluetooth Smart dongle, when fitted it showed the battery to be at 13.1v this matched what the control panel was showing. This afternoon it has reduced to 12.96v. I know this isn't a great drop however there is nothing at all on in the van and we have had a fair bit of sun this afternoon so would have expected to either hold steady or a slight increase?

Am I missing anything??

Cheers

 

[DBK]

The Victron should keep the battery at about 13.4 volts or thereabouts. But if it is very cloudy where you are it may not be able to do this. If it isn't charging the battery voltage will drop below 13 volts. Can you see any charging current when there is daylight?

 

[Lenny HB]

You don't say what type of battery but if a flooded cell, fully charged off load is 12.7v. After fully charging it will read around 13v but after a few hours will drop back to 12.7 to 12.9v. These are readings without the solar connected.
With the solar connected the readings will be higher as you will be reading the solar charge voltage.
Also with your control panel turned on there will bee a load on your battery of 300-500 ma.

Basically doesn't sound as if anything is wrong, if it continues to drop you may have a problem.

 

[LiquidLunch]

Thanks for that very helpful will keep an eye on it in the next few days...……...

 

[Abacist]

What is the state of the Cab battery? If its down it may be drawing current from your new battery via the battery master thus lowering the new tab battery if its not getting any solar input due to low or negligible sun!

^{_{Subscribers  do not see these advertisements}}