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d2dave
16th July 2023, 09:10 PM
I have a Tvan that has duel batteries. It has a Victron battery monitor. Doing some work I have noticed what appears to me as not monitoring both batteries.

See attached diagram. There is a shunt that takes the negative from battery B. From the other side of the shunt it then goes to a negative bus which is grounded to chassis

Battery A's negative goes straight to the negative bus. Shouldn't this also go through the shunt?

When power is being used, isn't it taken equally from both batteries, therefore only half is being monitored?

Am I correct or am I missing something?

186249

drivesafe
17th July 2023, 02:12 AM
Hi Dave and yes, both batteries should be earthed through the shunt.

If the batteries are close to one another, simply remove Battery A's negative ( - ) lead from the bus and connect it to Battery B's negative ( - ) stud.

If the batteries are mounted at different locations, it may be easier to disconnect Battery A's negative ( - ) lead from the bus and connect it to the same point on the shunt that Battery B's negative ( - ) lead is connected to the shunt.

With connecting the two battery negatives at the shunt, if you are using heavy loads, like running a large ( 1,000w or bigger ) 12v to 240vac inverter, then make sure the two negative ( - ) cables are of the same thickness and same lengths.

Are the two battery's Positive ( + ) terminals connect together?

d2dave
17th July 2023, 08:40 AM
Thanks Tim. Yes I thought every thing should go through the shunt.

No huge loads involved. Only 30L Engel, Fan for diesel heater or twin camec fans depending on time of year, a few LED lights and phone chargers.