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When charging the 4S module, be careful: when charging this module, be sure to monitor each of the four cells to ensure that they are tracking; i.e., that the voltages of each of the four cells are identical as the overall module voltage goes up.

How do I know this might be a problem? Earlier today I was slowly charging an old 11P16S LiFePO4 module with built-in BMS. After half-a-day of slow charging at one amp with amazing identicity of all sixteen voltages, I increased the current up to four amps to speed things up (still well under the 110A max spec) and it suddenly started to run away on me as the voltages on a few of the cell groups suddenly and dramatically increased. Luckily I was checking this every few minutes and shut it down before any damage was done (I hope). I need to go back and review the specifications as I'm shocked that the BMS didn't compensate. :shock:
Moral of the story: monitor the individual cell voltages carefully as you're charging your module.

<blockquote data-quote="JoeS" data-source="post: 41580" data-attributes="member: 250">When charging the 4S module, be careful: when charging this module, be sure to monitor each of the four cells to ensure that they are tracking; i.e., that the voltages of each of the four cells are identical as the overall module voltage goes up.How do I know this might be a problem? Earlier today I was slowly charging an old 11P16S LiFePO4 module with built-in BMS. After half-a-day of slow charging at one amp with amazing identicity of all sixteen voltages, I increased the current up to four amps to speed things up (still well under the 110A max spec) and it suddenly started to run away on me as the voltages on a few of the cell groups suddenly and dramatically increased. Luckily I was checking this every few minutes and shut it down before any damage was done (I hope). I need to go back and review the specifications as I&#039;m shocked that the BMS didn&#039;t compensate. :shock: Moral of the story: monitor the individual cell voltages carefully as you&#039;re charging your module.</blockquote>

[QUOTE="JoeS, post: 41580, member: 250"] When charging the 4S module, [b]be careful[/b]: when charging this module, be sure to monitor each of the four cells to ensure that they are tracking; i.e., that the voltages of each of the four cells are identical as the overall module voltage goes up. How do I know this might be a problem? Earlier today I was slowly charging an old 11P16S LiFePO4 module with built-in BMS. After half-a-day of slow charging at one amp with amazing identicity of all sixteen voltages, I increased the current up to four amps to speed things up (still well under the 110A max spec) and it suddenly started to run away on me as the voltages on a few of the cell groups suddenly and dramatically increased. Luckily I was checking this every few minutes and shut it down before any damage was done (I hope). I need to go back and review the specifications as I'm shocked that the BMS didn't compensate. :shock: [b]Moral of the story:[/b] monitor the individual cell voltages carefully as you're charging your module. [/QUOTE]

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