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Discussion Starter #1
Bought CALB ca's about 5 yrs ago and had some 4 out of 45 cells come up with high resistance out of spec and replaced by CALB on warranty. I have now 4 more with resistance higher than 1.2 milliohms (spec is .7 or lower) with one of those 4 at 2.2 milliohms. These are all figures reported by Orion BMS.
Anybody have any insight into why this happens and what a recommended course of action to take? buy 4 new cells? look for used cells? It seems that especially the highest resistance cell is cutting into usable range. I still have resting charge of above 3.2 on my best cell when BMS is cutting back 1238 controller output.

I guess this is a good question because I think I have asked it 3 times with very little response.
Thanks in advance
 

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Bought CALB ca's about 5 yrs ago and had some 4 out of 45 cells come up with high resistance out of spec and replaced by CALB on warranty. I have now 4 more with resistance higher than 1.2 milliohms (spec is .7 or lower) with one of those 4 at 2.2 milliohms. These are all figures reported by Orion BMS.
Anybody have any insight into why this happens and what a recommended course of action to take? buy 4 new cells? look for used cells? It seems that especially the highest resistance cell is cutting into usable range. I still have resting charge of above 3.2 on my best cell when BMS is cutting back 1238 controller output.

I guess this is a good question because I think I have asked it 3 times with very little response.
Thanks in advance
Possibly because they are just sitting and not being used. Not that all will go bad but non use is not always good either. I have some non use lithium too but have not checked in a long time. Im sure I'll run into that issue myself when I come to finally check them. Its kind of like someone pressing on your skin for years without letting up. Your skin breaks down and damage occurs. Im sure batteries are similar. Use them and they should do you well. I remember one person who I believe still recommends you not buy your batteries until right before you put them into use. I believe this would be good practice and one that many don't do.
 

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Discussion Starter #3
Thanks for the reply. They have been in pretty much continuous use since I installed them.
They may have sat a few times for several months here and there over the 4 years. but I have 25k+ miles on them and generally use the car as my daily driver. The Orion is set to balance charge at 3.55 I believe.
 

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Hi !

Are you sure that you have good and similar connections between all cells.
So the Orion doesnt measure the IR wrongly, or that there is a beginning problem with some connections. Make sure you clean all connections on the suspected cells and also the cells next to the suspect.

See if that makes any difference.

Best Regards
/Per
 

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Discussion Starter #6
yes cleaned connections and checked that Orion voltage reading matches my fluke meter reading at the cell. Just to make sure I will swap cells to make sure bad cell moves.
These were all installed polished terminals with light coat of noalox using tinned braided interconnects, and torqued to the specified 14 ft lbs
(20 nm)
 

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Bought CALB ca's about 5 yrs ago and had some 4 out of 45 cells come up with high resistance out of spec and replaced by CALB on warranty. I have now 4 more with resistance higher than 1.2 milliohms (spec is .7 or lower) with one of those 4 at 2.2 milliohms. These are all figures reported by Orion BMS.
Anybody have any insight into why this happens and what a recommended course of action to take? buy 4 new cells? look for used cells? It seems that especially the highest resistance cell is cutting into usable range. I still have resting charge of above 3.2 on my best cell when BMS is cutting back 1238 controller output.

I guess this is a good question because I think I have asked it 3 times with very little response.
Thanks in advance
Higher resistance is usually caused by capacity fade. I know of no way to reduce it you just have to replace the cells. You could take them out and cycle them four or five times. I did this with some cells that had been sitting on a shelf for years and I got 100% of the capacity back. This may not work for cells that were regularly cycled in a vehicle.
 
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