Solar_Mann
New Member
- Joined
- Nov 18, 2019
- Messages
- 71
I’ll try to keep this short while getting all the info out there. I’ll start with a little background. I’m a solar/battery enthusiast and mobile offgrid installer. Over the last 2years or so I’ve installed over $20k worth of lithium batteries, many of which are Chins.
The early ones had 0 issues from my experience. The newer ones, most specifically the ones with the heater and Bluetooth BMS are the most problematic.
Issue #1, they are shipping these batteries without the cells being top balanced. The issues this creates is the battery shuts off well before reaching 14.4 volts. They even spec 14.4-14.6 as charged voltage. The first time I encountered this was with a 24v victron system. On charge one battery would shut down at 13.8v, once one shut down it would cause the victron Quattro to shut down completely stopping all power from getting to the trailer even with the generator running. Chins did agree to swap the one battery but also told me to charge it at a very low rate for 24hrs to allow the BMS to do the balancing. I charged both batteries in parallel at about 1amp for a few days. This did help, I was able to achieve about 28v once in series before shutting down but this still below the well known and common 14.4 per 12v battery.
Another job came up with another 300ah smart chins, I ran into the same issue. The EPEVER tracer charge controller was set to 14.4v peak but the battery was shutting down around 13.7-13.8 once again. Same story as the previous install, one cell far out of balance hitting its 3.65v disconnect. After about a full day charging it had gone up about a tenth of a volt before shutting down.
I’d like to hear your guys opinions on this issue? Sure seems to me like cutting corners by not balancing cells. Literally telling me to let the BMS do the balancing, I feel this should be a required step at the factory. Will?
Issue #2. One of the installations I did using these batteries is a commercial install. The trailer has a lot of equipment that can pull a pretty heavy load from the batteries. The 2 300ah chins batteries are spec’d at 200amps continuous. Issue is after 20-30minutes at 160-180amps the BMS shuts down. All cells nearly perfectly balanced so my only guess is overtemp protection. One interesting thing is about 1-2 minutes before shut down the voltage starts dropping quickly, while the Bluetooth app still shows much higher voltage than actually voltage output. Guessing this is from something getting hot and increasing resistance.
Once again seems like shitty quality causing this issue, they can’t actually meet the specified output. I’d like to hear your guys opinions.
Just to clarify, I’m not saying they all are terrible. I have many functioning just fine and pulling full capacity without issue but like I said the newer ones seem far more problematic. I’d love to hear your guys opinions.
UPDATE 9/27/23:
A second battery of the same model that was purchased around the same time as the ones mentioned above has now completely failed. bluetooth app shows 30 cycles (been in use 8 months). App will show 97% charged and discharging at say 3amps, no issue. Add any larger load than LED lighting and it shuts off (voltage drops to 0) immediately but the app remains the same saying everything is on and functioning with 0 amps being output. only way to "turn it back on" is to have the solar jump start it if its day light or if a jumper pack is hooked up it will start discharging again at a low rate. Another failed BMS.
The early ones had 0 issues from my experience. The newer ones, most specifically the ones with the heater and Bluetooth BMS are the most problematic.
Issue #1, they are shipping these batteries without the cells being top balanced. The issues this creates is the battery shuts off well before reaching 14.4 volts. They even spec 14.4-14.6 as charged voltage. The first time I encountered this was with a 24v victron system. On charge one battery would shut down at 13.8v, once one shut down it would cause the victron Quattro to shut down completely stopping all power from getting to the trailer even with the generator running. Chins did agree to swap the one battery but also told me to charge it at a very low rate for 24hrs to allow the BMS to do the balancing. I charged both batteries in parallel at about 1amp for a few days. This did help, I was able to achieve about 28v once in series before shutting down but this still below the well known and common 14.4 per 12v battery.
Another job came up with another 300ah smart chins, I ran into the same issue. The EPEVER tracer charge controller was set to 14.4v peak but the battery was shutting down around 13.7-13.8 once again. Same story as the previous install, one cell far out of balance hitting its 3.65v disconnect. After about a full day charging it had gone up about a tenth of a volt before shutting down.
I’d like to hear your guys opinions on this issue? Sure seems to me like cutting corners by not balancing cells. Literally telling me to let the BMS do the balancing, I feel this should be a required step at the factory. Will?
Issue #2. One of the installations I did using these batteries is a commercial install. The trailer has a lot of equipment that can pull a pretty heavy load from the batteries. The 2 300ah chins batteries are spec’d at 200amps continuous. Issue is after 20-30minutes at 160-180amps the BMS shuts down. All cells nearly perfectly balanced so my only guess is overtemp protection. One interesting thing is about 1-2 minutes before shut down the voltage starts dropping quickly, while the Bluetooth app still shows much higher voltage than actually voltage output. Guessing this is from something getting hot and increasing resistance.
Once again seems like shitty quality causing this issue, they can’t actually meet the specified output. I’d like to hear your guys opinions.
Just to clarify, I’m not saying they all are terrible. I have many functioning just fine and pulling full capacity without issue but like I said the newer ones seem far more problematic. I’d love to hear your guys opinions.
UPDATE 9/27/23:
A second battery of the same model that was purchased around the same time as the ones mentioned above has now completely failed. bluetooth app shows 30 cycles (been in use 8 months). App will show 97% charged and discharging at say 3amps, no issue. Add any larger load than LED lighting and it shuts off (voltage drops to 0) immediately but the app remains the same saying everything is on and functioning with 0 amps being output. only way to "turn it back on" is to have the solar jump start it if its day light or if a jumper pack is hooked up it will start discharging again at a low rate. Another failed BMS.
Attachments
Last edited:
