Weize 100ah going crazy after 1 1/2 years.

[Captain Hook]

Here we go. Bought weize 100ah last year on Will's review for my new to me 32ft Endeavor sailboat. 420w of pv, HQST 40a. controller. 160ah of lead and the weize 100.
All was waay better than I imagined for 16 months. I installed a Weize 1200 watt inverter and am more than satisfied with performance. Couple weeks ago I ran the weize down to cutoff voltage and thought that it was way too fast according to calculated capacity. Then weize woseemed to only charge to 13.8 volts.(same controller factory settings for LI.I had no sun so I charged it with my 70amp alternator 5min. on 5 minutes.off and it worked like a champ. But, only to 13.8 even when the sun came back. This morning, I was working here and my lights went out. Battery was reading 10 volts and meter needle bouncing back and forth 9v to 11.5 back and forth. Cranked up the engine and after my lead was fully charged I switched it to both and it started charging LIPO. In a few minutes the reading was 14.5 (2minutes?) so I switched back to 1( lead only) and my meter needle for lipo4 stayed at 14.5 but bouncing 14.4 to 14.6 and still like that now an hour later. I only charged it on alternator for 2 minutes. 1. It should not have been dead when it was.
2. It couldn't have charged in 2 minutes.
3. SOMETHING AIN'T RIGHT.
SO,,,,,BMS? BAD CELL? WHAT THE HELL FELLAS?

 

[Q-Dog]

One single LiFePO4? and you tried to charge it at 70 amps?

 

[Captain Hook]

Here we go. Bought weize 100ah last year on Will's review for my new to me 32ft Endeavor sailboat. 420w of pv, HQST 40a. controller. 160ah of lead and the weize 100.
All was waay better than I imagined for 16 months. I installed a Weize 1200 watt inverter and am more than satisfied with performance. Couple weeks ago I ran the weize down to cutoff voltage and thought that it was way too fast according to calculated capacity. Then weize woseemed to only charge to 13.8 volts.(same controller factory settings for LI.I had no sun so I charged it with my 70amp alternator 5min. on 5 minutes.off and it worked like a champ. But, only to 13.8 even when the sun came back. This morning, I was working here and my lights went out. Battery was reading 10 volts and meter needle bouncing back and forth 9v to 11.5 back and forth. Cranked up the engine and after my lead was fully charged I switched it to both and it started charging LIPO. In a few minutes the reading was 14.5 (2minutes?) so I switched back to 1( lead only) and my meter needle for lipo4 stayed at 14.5 but bouncing 14.4 to 14.6 and still like that now an hour later. I only charged it on alternator for 2 minutes. 1. It should not have been dead when it was.
2. It couldn't have charged in 2 minutes.
3. SOMETHING AIN'T RIGHT.
SO,,,,,BMS? BAD CELL? WHAT THE HELL FELLAS?

Update. My controller Bluetooth says battery at 14.2? Normal operation. I am going to now put the 6amp <> load to it and see what gives.

 

[Captain Hook]

Update. My controller Bluetooth says battery at 14.2? Normal operation. I am going to now put the 6amp <> load to it and see what gives.

OK. It immediately went down to 11v and is staying there steady. No bouncing.
My uninformed, uneducated guess is some kind of BMS problem. Please feel free to educate and inform me. My new 100ah AOLITIUM comes in thursday.

 

[Captain Hook]

Update. My controller Bluetooth says battery at 14.2? Normal operation. I am going to now put the 6amp <> load to it and see what gives.

OK. It immediately went down to 11v and is staying there steady. No bouncing.
My uninformed, uneducated guess is some kind of BMS problem. Please feel free to educate and inform me. My new 100ah AOLITIUM comes in thursday

One single LiFePO4? and you tried to charge it at 70 amps?

It is rated for100a continuous but yes, not suspecting the alternator runs that high normally anyway. I am trying to remember if all this started about the time I started using the alternator. Suspiciously, I would have to admit.....yes

 

[Captain Hook]

I am a marine electrician and retired 40year Yacht Captain in the Carribean. Able to do repairs to the battery if necessary.

 

[Captain Hook]

According to Will's review this battery is 2 50ah small form cells in series. Did I overlook that small detail?

 

[Q-Dog]

OK. It immediately went down to 11v and is staying there steady. No bouncing.
My uninformed, uneducated guess is some kind of BMS problem. Please feel free to educate and inform me. My new 100ah AOLITIUM comes in thursday

It is rated for100a continuous but yes, not suspecting the alternator runs that high normally anyway. I am trying to remember if all this started about the time I started using the alternator. Suspiciously, I would have to admit.....yes

No, it is rated for 100 amp Max. Standard charge rate is 50 amps or less. For these battery cells to remain balanced they want slower and longer charging.

 

[Captain Hook]

OK I get it. I have a 40amp dc to dc coming today. I plan to pull that battery, disassemble and do a Will guided YouTube troubleshoot fiasco.

 

[Captain Hook]

So, straightforward question. What gets damaged from my genius move of 70a alternator input?

 

[Q-Dog]

I doubt there is any permanent damage. The BMS has a limited amount of balancing ability. When you regularly charge at a high rate the battery cells get unbalanced because the BMS balancer can't keep up. If you can charge at a slower rate, and float the battery for a few hours every now and then it is more likely to stay balanced.

 

[Captain Hook]

OK. I need sun. Or I can use my engine and lead bank. Inverter to 120v 12amp charger until the sun comes out later today. Is that a reasonable step in the right direction my friend?

 

[Q-Dog]

Yes. I would put a light load on the battery to discharge it some first.

 

[Captain Hook]

It's at 11 now

 

[Q-Dog]

Try to charge it with the slowest charger you have. Set to 13.8 - 14 volts and see what happens.

 

[Captain Hook]

I have a 12 amp to 2amp Schumacher 13.8 volt charger to put on it. Maybe at 13.8 they will balance if I leave it on 2amps with 13.8 soc

 

[Captain Hook]

Charging on13.2 now should rise on soc.

 

[Captain Hook]

I am at 13.5 on my panel volt readout. But my charge controller says 14.1. Controller also says 35.5 pv and 4.5 amps charge current with a completely cloudy sky . No sun whatsoever. It said that yesterday too. But last night it said null as it should. This isn't possible. Is it??

 

[740GLE]

So for the life of the battery has it been able sit at >13.8v at the terminals for hours at a time?

Also your first post mentioned 160ah of Lead, does that mean you have FLA connected to the LiFePo4?

Any chance you could post a picture from the SCC and wiring to the battery terminals? I don’t like that the SCC thinks the battery is at 14.2v, to me that means there’s a good voltage drop from the SCC to the battery terminals.

Also on the SCC can you turn down charging current to a max of 5A?

 

[Captain Hook]

Allright. Extensive testing shows: when controller shows 14.1 the Chinese 30 amp push button breaker only shows 13.5 downstream. That figures. Used to read the same. When controller reads 13.6 breaker shows 13.5 downstream. Conclusion 1: breaker allows maximum 13.5 downstream. Theory 1. This is why my weize has not been charging past 13.5 for a week or so. Questions: 1.Did I imbalance my battery so much by putting 70 amps charging in it that the capacity seemed very diminished? 2. How diminished does 13.5 for charge voltage make my battery? 3. Could I have damaged cells by 70amp charge current? Answers from knowledgeable folks only please. (No disrespect intended). ME? Replace breaker. Pray nothing is fried.