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gefmar avatar image
gefmar asked

bmv 700 voltage readout different to actual readout at battery terminal

Gauge readout shows 13.84v and at battery 13.91v

Can anyone tell me why as I have lithium set up and need more accurate readings for float etc

Cheers

Geoff


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2 comments
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Kevin Windrem avatar image Kevin Windrem commented ·

A couple things come to mind:

1) There might be a difference between the BMV700 and the multimeter you are using to measure at the battery. Measure with your multimeter at the shunt to see if there is a difference there. If so, try another multimeter or just chalk it up to 0.5% error.

2) If current being drawn from the battery the voltage at the shunt WILL be lower due to voltage drop in the cable between the battery negative terminal and the battery terminal on the shunt. Minimize the length of this connection and make the wire as large as you practically can to avoid this drop.

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gefmar avatar image gefmar Kevin Windrem commented ·

I have a short heavy lead and have tested at the shunt with same results

The system also has 600w of PV running through an Enerdrive 40 amp controller which shows on the readout the same voltage as the multimeter?

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1 Answer
klim8skeptic avatar image
klim8skeptic answered ·

Check the fuse. It should be a 1a job.

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