CHINS battery reads 1.2v, toasted?

[waygonewilco]

My stupid renogy controller is acting up again, and my battery did not receive any charge for 24 hours (even though perfectly sunny outside).
I have a 200ah CHINS battery with built-in BMS. After being drained, the battery reads 1.2v. it is currently on a charger per support instructions from CHINS.
Is this just a weird value after the BMS disconnect triggered? Or is this battery f*****? What do I look for after charge to verify battery integrity?
Thanks all

 

[sunshine_eggo]

When the BMS is in protection mode, it reports a very low voltage. An oddly low voltage when this hapens is common across all brands of batteries.

This is normal behavior. The battery is protecting itself. Hopefully, it recovers as it should.

You may need to parallel it with another 12V to wake it up. Not all chargers know what to do with a battery reading 1.2V.

 

[waygonewilco]

Thanks sunshine, that is reassuring. We'll see in the morning how it recovers.

 

[waygonewilco]

Thanks sunshine, battery recovered just fine and appears to be operating normally. Will be monitoring to see if capacity had been affected

 

[Texas-Mark]

Will be monitoring to see if capacity had been affected

It should be fine. BMS was doing it's job.

 

[Adam De Lay]

My stupid renogy controller is acting up again, and my battery did not receive any charge for 24 hours (even though perfectly sunny outside).
I have a 200ah CHINS battery with built-in BMS. After being drained, the battery reads 1.2v. it is currently on a charger per support instructions from CHINS.
Is this just a weird value after the BMS disconnect triggered? Or is this battery f*****? What do I look for after charge to verify battery integrity?
Thanks all

Which Renogy controller do you have?

 

[waygonewilco]

Which Renogy controller do you have?

Renogy Rover 40 amp. Twice in the past month it has read the battery wrong, saying it was charged as the battery dropped to 0%.
It also read a 0.8v higher reading than the actual battery reading, making it so I have to raise the charging values to levels that make me uncomfortable to even get the battery to 70%.

I have an Epever that I'm going to replace it with, just need the time.

 

[Texas-Mark]

Renogy Rover 40 amp. Twice in the past month it has read the battery wrong, saying it was charged as the battery dropped to 0%.

Be aware that you can not go by the Rover's SOC reading. It is only using voltage to guestimate it.

It also read a 0.8v higher reading than the actual battery reading,

See this thread of mine regarding that issue. The rover will work, you just have to find the sweet spot with the settings (user profile not Li profile).

Acceptable voltage drop from CC to battery?

I have a Renogy Rover 40 CC with 8 100W panels (4S2P) on my cargo trailer conversion. The panels are flat mounted, so obviously output is less than 800W most of the time. From the Rover, I have 4 feet of #6 cable. Note: The Rover manual states max size of #8 for the connectors, but #8 is only...

diysolarforum.com

 

[Adam De Lay]

Renogy Rover 40 amp. Twice in the past month it has read the battery wrong, saying it was charged as the battery dropped to 0%.
It also read a 0.8v higher reading than the actual battery reading, making it so I have to raise the charging values to levels that make me uncomfortable to even get the battery to 70%.

I hated all the inconsistent voltages my old Renogy 40a had. The display had 1 voltage, the app had another and the meter had another. Got rid of those real quick.

 

[waygonewilco]

For awhile it was a consistently high voltage reading, which worked. Now it randomly reading strange values, such as 2.4v, when my battery is at 13.1v, or reading 14.6v when the battery is near dead.

 

[sunshine_eggo]

For awhile it was a consistently high voltage reading, which worked. Now it randomly reading strange values, such as 2.4v, when my battery is at 13.1v, or reading 14.6v when the battery is near dead.

Please clarify your statements.

It reads 2.4V when it's at 13.1V. How can something report two different values at the same time?

Reading 14.6V when the battery is near dead - what's reading 14.6V? If you have a charger connected to the battery, are you reading the voltage of the charger output or the battery itself? If a battery is in protection mode, it is electrically disconnected from the charger, and any voltage you measure at the terminals will be that of any chargers attached.

It might be time to give a little more detail on your setup.

 

[waygonewilco]

Sorry for the lack of detail. In that example, the charger was displaying 2.4v while I measured 13.1v at my battery, and at a different time the charger reading 14.6v no matter that voltage being measured at the battery

I have ~400 total watts, a Chins 200 ah battery with built in BMS, and I was using a Renogy Rover 40 amp until I replaced it with an Epever tracer today.

What I believe is happening is that the charging settings on the charger were too high, which was messing with the BMS. This happened on the Rover and the Epever after I swapped it out this morning. Reducing the charging limit and various other settings has stabilized the charging for now

 

[df00z]

I had to use a custom charging profile on my Renogy 40a rover. Chins had different recommended charging voltages for my 300a. It's been fine since following the recommendation.

 

[df00z]

But um, so if there is a massive voltage differential between the charger and battery - like if your boost voltage is high, and you throw a large load on - the line voltage raises above battery voltage. Super complicated math, actually.

Different voltage sources in parallel

I realize connecting two different voltage sources in parallel is a contradiction (in an ideal circuit). But if I were to connect this in practice and measure the voltage across points A and B, what

electronics.stackexchange.com

When you put a load on the circuit, the battery charger may end up providing a large current and the voltage sinks which looks like a dying battery.

I was throwing 100-150 amp loads on the system, the voltage drops to a point where the bat acts as a buffer but the charger can get really angry.

I think Chins recommends like a 13.2-13.4 float, 14.8 is way too high boost. Low 14 is good.

I tried asking people here if they disconnect their chargers under large inductive or inrush loads. I am running a lot of power tools on my inverter.

My system has been fine since lowering the voltages. I am running an AC and some saws and drills.

The BMS will stop charging entirely for some unspecified time unless you bluetooth in and turn it on on some chins batteries.

Definitely been ok since adjusting to a custom profile.