Cooked Nation's Alternator with Wakespeed/Victron/Rec Active BMS system. Need help troubleshooting BMS after replacement

• W

  W

  6/10/24, 11:48 AM

  Hello,

  
  Background:
  For the last 4 years, I’ve had the rec active bms connected to my van power system. I have (16)280 amp 3.2 lithium cells oriented in a 12v 4p4s pack with 1120 amp hours of power. It is charged via a Nations alternator with the Wakespeed controller. I have the Victron Cerbo and Victron Multiplus inverter and primarily charge my batteries with the alternator.
  
  Problem:
  My rec bms is showing a “Cell Voltage Measuring Error” and I’m not sure how to reset it. I’ve attached screen shots of what I’m seeing when I connect via WiFi. This all happened when I made two changes: I replaced the nations alternator with the same model and I replaced a lead acid battery I had in parallel with the lithiums with a new one. I disconnected the new lead acid as I thought this may be the problem, but it didn’t fix it. I also restarted the bms multiple times and reinstalled the latest bms firmware, which was unsuccessful too.
  
  Extended background:
  My nations alternator started smoking last week and was totally fried. Battery was still working fine though and I didn’t get any alarms.
  
  2 things I think may have contributed to the burned out alternator .
  
  1. Nations told me that I should have had a negative wire from the alternator back to the battery. I just had a positive wire back to the battery along with the temperature probe and field wire to the Wakespeed. I did have a negative wire from the alternator to the vehicle chassis though. However, I install a negative cable straight back to the battery with the replacement. 
  
  2. Before this system I was using a Balmer controller with the Nations alternator and a different lithium system. Back then I had a lead acid battery parallel to the lithium battery to avoid load dumping if the lithium system was ever accidently switched off while the alternator was running. The lead acid battery would act as a buffer and absorb the energy from the load dump. The lead acid died sevreal years agio, but I left it the system when I upgraded to the wakespeed/red active bms system with the new lithium cells as it was under the van and difficult to access. I didn’t think I would need it anymore since the rec bms should turn off alternator charging before shutting down the batteries preventing any load dumping. I did connect the lead acid from the cicuit in hopes of correvctiug the issue, but no such luck. 
  
  
  

  

  

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• R

  Rick OGM Support Staff

  6/10/24, 12:08 PM

  It sounds like you may have blown some fuses in the REC BMS when you were moving things around.

  Also, how many beeps/LED flashes are you getting from the BMS?  This will give us an error code # to reference.

  To check your fuses grab an M10 torx driver and remove the screws on the end of the BMS and slide out the card.  Look for black squares, a bit smaller than a chicklet, and likely with a dab of silicone on them.  They will pull right out.

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• W

  W

  6/10/24, 12:19 PM

  @Rick Thanks for the advice. I'll take a look later this morning. Would a blown fuse still allow the bms to turn on and sense the voltages as above? Although it says "cell voltage measuring error", it actually shows all the voltages of the packs and they are all balanced. 

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• W

  W

  6/10/24, 2:53 PM

  Well, I pulled the bms and checked all the fuses, which were all good. When I reassembled everything, it all started working again. Think this likely reset the bms. Didn't know there was a battery on the circuit board and wonder if this kept me from resetting it before. Anyway, thanks for the help. Although I do like tinkering, I'm wishing someone would come out with a completely plug and play system option that didn't cost as much as a civic. 

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