Victron BMV and charge not working?

[Troutboy]

I’m in the middle of a trip and something happens with my battery and monitor.

I can’t seem to charge with solar anymore. It shows there is voltage, but no amps.

The Victron lithium batteries have a charge of 13.14V. The monitor I set to show 100% at 13.9V

I turned the battery disconnect on by accident and now the SOC shows 100%. But it’s not. I think because it shows at 100% I think the charger won’t charge?

Also strange is that the BMV shows 13.14V. But the charger shows 14.2 or 13.6 which are the adsorption and float charge set points.

I also noticed that when I manually set the float to any number, it reads that voltage from the battery, even if the battery is something else.

I have tried turning both off for a while and turn back in and tried reset with no luck.

Also, the battery keeps draining down as we use electric which you expect, but whenever I use the battery disconnect to shut off, it resets gate of charge to 100%.

Any help would be appreciated or suggestions. I’ll be in town for a few hours then back again to tomorrow evening where I have connectivity.

Thanks!

[uncle_bob]

Hi

It sounds *very* much like your charger is on one side of things and the battery is on the other side of things. I'd check for blown fuses or loose wires between the charger and the battery.

I ... ummm ..... errrr ..... have direct experience with this exact problem. In my case it was a breaker that I'd put in. It tripped to protect the battery. In isolating the converter, it let it go to > 20V, that was not ideal for various other bits and pieces of the trailer ..... Net result was similar (but *not* identical) to what you are seeing.

Start at the charger output with a multimeter and track the voltage on the circuit as it goes to the battery. At some point along the way there will be a surprise ....

I suspect I missed your time window ... sorry about that ....

Bob

[wulfraat]

Rich - remind me - do you have a CCGX and is DVCC enabled?

Where are you reading 100% SOC from? Your Mppt controller via Bluetooth / app?

[Troutboy]

Thanks Peter and Bob.
No CCGX.

We are making it so far, one more night. What is really strange is that the BMV is only reading 13.1 no matter what.

I’ll do what you suggest bob and see what blew.

I was wondering if it could be a bad charger or BMV?

Strange that we keep running everything with no issues and the battery is just staying at 13.1 now. Has to be a blown something.

[wulfraat]

Maybe bad bmv shunt or mppt voltage reader.... but if this is a Non-CCGX networked install then the mppt and bmv don’t talk to each other, hence if the mppt controller is not seeing low voltage and charging accordingly that leaves me to believe that this is a bad mppt unit.

[uncle_bob]

Hi

If the battery is really sitting at 13.1V ( = check it with a multimeter ...) you are fairly far into the discharge curve. The MPPT *should* get going and dump power into the system. It will only do this if it "sees" the 13.1V on it's output pins. If it sees 13.6 or 14.2, it's not going to dump any power into the battery. I'll just sit there and do nothing. ( = check that with the multimeter).

======

I have a Victron battery isolator in my setup. If it "fires" the battery comes loose from pretty much everything. That may or may not be the ideal outcome under all conditions. If it does separate the battery from the loads ( and ... errr ... hmm ... most ... of the charging ... ??? ... back to my notes ... hmmm ... notes ... errr ... ) odd things will result.

Indeed this all *does* point out that just maybe I should do a coherent set of notes detailing just how things *are* hooked up in the trailer. If I'm guessing a few months later, it's going to be utterly impossible to work out a year or two from now. Oddly enough, the best details are probably in my forum posts and our back and forth discussions about what to put where..

Bob

[uncle_bob]

Hi

Just remembered one other thing .... looking at my "spare" MPPT here on the shelf ....

The first MPPT I got did some weird stuff in terms of hooking up to the main system. I poked at this and poked at that. Eventually I replaced it because I was just out of time. Once I got it out and fully power cycled it, it played nice with everything. Possibly as a last resort, fully powering down the MPPT might be something to try.

Bob

[Troutboy]

Okay, problem solved..... I feel really humbled and stupid. I took Bob's advise and started tracing back. SInce the solar was not working, I started at MPPT. I looked closely and this time was not fooled. I have a 60A breaker between the MPPT and the Battery, it was tripped. When I reset it, Voila! everything worked again.

I swear I looked at that thing and must have mistaken the on position for off. Anyway, crisis averted, and everything went great on a 4 day trip up to Steamboat Springs, CO.

Thanks again Bob and Peter for your replies and help.

Darn gremlins always complicating things.....

[uncle_bob]

Hi

Hey ... tripped 60A breaker !!! That sounds *very* familiar ( = it was part of my "problem" as well ...). Sure wish I'd found the issue *before* the LED lights all burned out ... live and learn

Glad you found the problem and it was something simple.

Bob

[Troutboy]

Sorry about your LEDs Bob,

So I’ve been searching but can’t find a good SOC vs voltage chart for LIFePO4 12V batteries. Do you have a good source? I know a bunch depends on amp draw and temp, but looking to understand better.

Mine seemed to be stuck at 13.1 for a long time. How far down was that? Did I damage the batteries?

Thanks
Rich