[johnny]

" This over voltage on inverter was triggering, but only when batteries were fully charged and it was daylight. ---"

setting in solar controller are wrong to trip inverter.

[scubadoo]

Steve.
If you suddenly observe 17V on your multimeter while the battery appears to be charging normally at say 13.xxV then I can only envisage a couple of possibilities.
The voltmeter/multimeter is just reading a spurious RF induced spike. No concern.
The battery internal BMS circuitry spontaneously briefly isolates the connection between the battery terminal(s) and the external load terminal(s) on the case. The terminals could then read almost anything without the battery connected.

How long do the observed peaks typically last?

I may have missed something else but it would be virtually impossible excluding cell failure given the low impedance , absorbtion capabilities and the resulting voltage smoothing for the actual battery voltage to jump suddenly.
I.e. I doubt the battery itself ever saw any spike but as you mentioned any loads attached could and that may not be too healthy for some devices.

I will also follow the suppliers reporting with interest.

[CatholicKiwi]

Neville- the spikes will last for a split second I guess. Its enough to trip the nomad inverter over voltage cut off. Happens with the 2 batteries in series (35v spike) and also one battery at a time if connected as 12v, each battery does the same when replaced in the 12v system (one battery at a time) 17v spike when 12v system. Seems to happen approx 10 minutes apart although I haven't timed this.

I recall some time back talking to a person at AASolar regarding 'drop in replacement ' type of lithium batteries. He implied that it was hard to find batteries with inbuilt bms that 'play nicely ' with charge controllers (such as the epever tracer etc )

I do have a theory - I'm wondering if this is what AA Solar were talking about. Somehow when the BMS is 100%SOC something happens but the charge controller doesn't recognize this something and trys to send charge or voltage to the battery. I think aa solar said something like the bms disconnects the battery from the controller when full, so the controller doesn't 'know ' a battery is there. Would the charge controller then just send a high voltage down the output to battery wires? If you have a solar panel connected to a charge controller (no battery connected though) would there be anything registered at the controllers battery connector terminals? Say, that spike voltage for example??...Regardless- the batteries sit at normal voltage, then there is a slight fluctuation, then split second spike, then back to normal. BMS disconnects? Batteries sit at normal voltage for 10 mins or so. BMS reconnects? Voltage fluctuates, spike, BMS disconnects , and repeat process. My theory anyway....

[CatholicKiwi]

Just been talking to Benson who has been very helpful. He's tested the batteries, and says they seem fine. So I will purchase another Epever charge controller from him and see if that makes a difference. Perhaps there is something wrong with my charge controller. (Even though it works fine with non- lithium batteries) Further update after I receive the new charge controller...

[NeilV]

Are you saying he can’t replicate your issue with the ‘new’ epever charger he’s now selling you?

[CatholicKiwi]

Neil, that seems pretty much what he's saying. Batteries and new Epever controller arrived this afternoon, so will know tomorrow or Sunday if its problem solved.

[Stephanv9]

Hi there, just wondering what the outcome was on your battery. I have purchased a 200ah lithium valley battery as well and am seeing exactly the same issue. I have a new victron mmpt
Solar controller and can monitor voltage in real time. When fully charged and its sunny out, I can see blips where the battery voltage spikes to close to 17 volts. This is with the controller set to 14.2 volts. I’ve tried setting the controller to 13.95 volts but same thing happens. Did you find a resolution? The guys on the Victron community are suggesting it’s the bms on the battery tripping. Regards Stephan

[johnny]

?