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platypus asked

Victron Battery Monitor doesn't seem to be discharging

My battery monitor seems to be stuck at 100%, even with several loads connected to it.


- I'm confident it's wired in the correct oritentation

- All loads are connected to one side, and it's the only thing connected to the NEG terminal of the battery


I wonder if it has something to do with my settings?


I have this battery: https://www.batteriesandsolar.co.uk/wp-content/uploads/2020/06/TN-Power-TN100-Data-Sheet-CLICK-HERE.pdf


And the settings I currently have are here:

screenshot-20220525-082419.png


I've messed around with the settings a bit:


- I moved the charge voltage from 12.8V to 13.8V.

- I've also moved the charge efficiency factor from 95 to 99

- I've moved the Peukert exponent from 1.25 to 1.05

- I turned off the "Battery starts synchronized" - this one I think could've been a problem, as I don't think it should assume the battery is chargd at the start


No idea if these are correct, and the data sheet i linked above doesn't really have those values. -- What should the settings be set to?

-- EDIT --

I took another read of the documentation and re-set:


- Voltage to 13.2V

- Moved the discharge floor to 15%


I wonder if the best bet is to remove the battery, fully charge it via mains, then "synchronize" the state of charge to 100%.


With a couple more loads, it's now down to 99% - but I still feel it's off. A fridge had been running at 1-5amps for three days now. It should be max in the low 90s.

BMV Battery Monitor
screenshot-20220525-082419.png (248.3 KiB)
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2 Answers
JohnC avatar image
JohnC answered ·

Hi @platypus

With Li the charge V curve is very flat, so it's important not to set the Charged V too low. Your link suggests charging at 14.6V, so you could try 14.4V. It also suggests a '0.02' Tail when fully charged. That's 2%, so 3% might be suitable.

What you could also do is set the SOC manually to (say) 50%, and watch it on the VictronConnect Trends graph while it's charging. It will sync to 100% when it's ready. With a low Charged V setting, sync can happen prematurely, and be useless.

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platypus avatar image platypus commented ·

Interesting - so if I manually set it to 50% and apply the settings you mention above it should right itself?

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mkuiken avatar image
mkuiken answered ·

Have Hi @platypus

Regarding you remark "All loads are connected to one side, and it's the only thing connected to the NEG terminal of the battery":

Can you confirm that only the shunt is connected to the NEG terminal of the battery?

Can you share a wiring diagram of your setup, and a photo of your shunt installed?

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