Shunts

[Steve9007]

Want to talk about shunts, I have searched on here also but wanted to ask, does the size of the shunt you pick get decided on the power from your biggest draw, or size of batteries being used or something completely different. Should it be the same size in amps as your mega fuse protecting the main pos from your inverter which in my case is the 12/3000/120a one. I know that it’s needed to be able to monitor battery health through my victron system but ain’t sure of the size required. Appreciate all responses. Tia 

Edited May 10 by Steve9007

[jonesthenuke]

Size to your estimate of largest current draw. Battery capacity is not relevant.

[Tony Brooks]

The resistance of the shunt must be matched to the monitoring device/ammeter, otherwise the reading will be incorrect.  If Victron offer a range of shunts rated at different amperages but all having the same resistance, then you can choose, but I doubt they do.  If they do, then choose one that is rated for a higher current than the cable or megafuse.

[Jen-in-Wellies]

59 minutes ago, Tony Brooks said:

The resistance of the shunt must be matched to the monitoring device/ammeter, otherwise the reading will be incorrect.  If Victron offer a range of shunts rated at different amperages but all having the same resistance, then you can choose, but I doubt they do.  If they do, then choose one that is rated for a higher current than the cable or megafuse.

Victron shunts are all 50mV drop at their highest rated current. Presumably you either program the attached battery monitor with the size of shunt attached, or it might even be able to detect the shunt capacity automagically.

Their lowest current one is 500A, which will be fine for the OPs 3000VA inverter.

https://www.victronenergy.com/accessories/shunt-600a

[Steve9007]

ok thanks guys, much appreciated 😀