Renogy 50a dc-dc charger with mppt killing everything.

[Antmeister]

Not sure how this unit could be causing the symptoms you are seeing. You are getting a cell OV when your battery is only at 13.1V. You say the cells are balanced, but the second picture shows the pack voltage at only 12.98v. IMO you need to top balance the cells.

Because my batteries Are primary Just for solar, I've always been at the bottom. The only time my cells were top balanced where when I bought and tested them at my mates shop. The whole idea for the dc to dc is for winter in the uk when solar is nonexistent .
I've been reading and it seems I could use the gel setting for my dc to dc. Would anyone say this is good or bad?
I'm currently Putting in a emergency Switch on the alternator Wire to shut off before I shut my engine off. Remember I only get the high voltages when my engine has been shut off for a few minutes And it equalizes back to normal. But triggers my bms to shut down. So something's happening On the initial Ignition Off stage to launch high voltages Into my lifepo4.

 

[mikefitz]

gel setting for my dc to dc. Would anyone say this is good or bad?

Possibly, or you could use the Renogy app to set up a user charge profile.

Putting in a emergency Switch on the alternator Wire

Perhaps not a good idea, the alternator needs to beconnected to the starter battery.

The Renogy unit is a battery to battery charger and the default charge voltage is 14.4. Evidence so far suggests unbalanced cells, so its very possible you will get BMS shutdown due to cell over volts, when attempting to charge to 14.4volts.

theyre exactly as it shows on the bms. then after about 2 minutes they correct fast

It's unbelievable the cell volts, read on a meter at the cells, will change from over volts or under volts to normal, in two minutes .

The cell volts displayed at 50% SOC showed a higher delta than normal at 32 mV. Either a cell or BMS calibration or interconnection issue.

Perhaps evaluating the battery performance with an AC charger, ideally a charger with user variable charge voltages, would help identifying the issues. At least it would confirm the battery and BMS are functioning correctly.

Having pictures of the battery and installation with additional circuit diagrams will help the discussion.

Mike

 

[Checkthisout]

Bad cell?

 

[justgary]

I'm currently Putting in a emergency Switch on the alternator Wire to shut off before I shut my engine off.

Perhaps not a good idea, the alternator needs to be connected to the starter battery.

@mikefitz is correct. Disconnecting the load from your alternator with it running will very likely blow the regulator transistors and/or rectifier diodes.

 

[Antmeister]

@mikefitz is correct. Disconnecting the load from your alternator with it running will very likely blow the regulator transistors and/or rectifier diodes.

No what I meant was the wire going to my dc to dc from my engine battery. I've seen a few people on YouTube With emergency Switches installed to isolate from the engine battery.

Today I used a 30amp charger on my batteries and never had any issues with cells going bad.

I'm going on a long drive this evening, so can see the outcome of it all again. I'll try to get a screen recording of what happens on my bms when I shut my engine off.

I cant get photos of my setup because it's all compact in a cupboard In my van.

 

[Antmeister]

Possibly, or you could use the Renogy app to set up a user charge profile.

I dont have bluetooth To connect to it