BMS Charging Port Perplexed

[rippysig]

Ok, I’m perplexed. I have had system set up for awhile without any real power draws but lately I have been using it regularly on my off grid property. System is 180 amp lifepo4 battery with 60 amp cells in 4s3p configuration. I’m using a Daly 4S 100 amp BMS with a separate port for charging. I’m charging with a Rich Solar 40 amp MPPT with 4-100 watt panels. Max load is about 100 watts out of a 400 watt inverter.

lt seems like the charging port on the BMS is turning off and then not turning back on. This causes the battery to completely drain since nothing is going in. It has done this a few times but until today just unhooking the load got it working again. Today I actually had to charge the battery through the common port until the voltage came up enough and then the charging port started working.

It just seems like a faulty charging port on my BMS. I know I could bypass it and charge directly according to Will. But is there something else I should be aware of? Is there other reasons why the charging port would just stop working?.

 

[MisterSandals]

I’m using a Daly 4S 100 amp BMS with a separate port for charging.

I have a Daly separate port BMS and the charging is REALLY small, 8A on a 60A BMS. Maybe you're exceeding your separate port charge limit and thats making it cut out?
Otherwise, i dunno. If its not bluetooth then its a mystery as to what a BMS is thinking and doing.

 

[rippysig]

I’m wondering the same? But the BMS charging port is rated for 40 amps.

 

[MisterSandals]

But the BMS charging port is rated for 40 amps.

You shouldn't hit 40A with 400W of solar.
If you were interested in figuring this out, i'd throttle SCC back to 20A if possible and see if it keeps cutting out.

Or keep track of anything going on when it cuts out and see if there is any kind of pattern or clues.

Sorry, thats all i got.

 

[rippysig]

I was using the default lithium profile and I’m thinking it could have hit BMS limits so I put in custom float values from Will. We will see if that fixes it. It had been floating at 14.4….

 

[MisterSandals]

and I’m thinking it could have hit BMS limits so I put in custom float values from Will. We will see if that fixes it.

Your BMS should show that it hit a limit and likely keep a count.

A custom float value from Will? That seems really odd that you were floating lithium at 14.4V.
I cannot imagine how a float value would cause "BMS is turning off and then not turning back on."

 

[rippysig]

For some reason the ground on my solar charge controller to the battery was not as good as it needed to be