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BougeRV 100ah LifePO4

Skinny76

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Joined
Jan 17, 2020
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So, I bought the BougeRV battery that Will reviewed where the BMS wasn't plugged in all the way. It has performed well running a 12v fan and using an inverter to power a CPAP on a few occasions. It has been about a month now. I have not tested capacity.

I connected a Victron Smartshunt to monitor it. I do have an issue though. It has never cut off while in use, but the BMS must be kicking out every now and then since I can be at 65% (just for example) and without a charge, the Victron shows an instant jump back to 100%. It has done this three times in a month. I assume it is the BMS of the battery.

I don't have anymore info the that, but just wanted to put it out there. Could it be the shunt? I have everything torqued down well.

Thoughts?
 
To determine if it's BMS cut-out, disable "starts synchronized" in the shunt settings. When this is enabled, a power loss forces 100%. If disabled, you will get "--" indicating it has no idea what the SoC is because it's been reset.

Most likely, the shunt is not properly configured.

If you are charging with solar, you MUST specify 0.2V below ABSORPTION voltage, not float. Variable nature of solar can trigger false sync if charged voltage set 0.2V below float.

The only time you use 0.2V below float for sync criteria is if you are AC charging. However, with low current, you need to make sure the tail current is a little below the charger current, e.g., default is 4%. That's 4A on a 100Ah battery. If your charger is only putting out 3A, as soon as it crosses the float threshold, it will sync. You would want to specify 2% for a 3A charger.
 
Not sure what happened to my comments, but it did happen again and here is what my shunt shows. Any ideas?
 
The "--" indicates the shunt lost power at some point. Likely either its power connection is bad, or the BMS triggered low voltage protection and cut power.

It won't show 100% until it achieves the "charged" criteria.
 
Ok. This battery keeps shutting down for no reason. Temp and voltage is OK. The BMS must be messed up. I can't recommend this to anyone. Better options out there.
 
Are you using this one?

Sorry for the late reply, but that is the one. It still occasionally shuts off, but has never cut off under load. It is stationary, so movement isn't the issue. I think I just got handed a learning experience. Worse case is I cut it open, fix it and just keep the cells out of the case. I'll hang the case on the wall as a reminder that pretty cases do not mean a good battery.
 
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