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jan-gils avatar image
jan-gils asked

Quattro/Skylla in combination with alternator voltage runaway

We've just had some big damages on our sailboat because an overvoltage scenario. We normally run a Quattro (100A) + Skylla-i (100A) parallel to charge a 24V LiFePO4 battery. This has been working just fine for the last year.

Recently we also started the engine and alternator with a Wakespeed regulator (max 75A). It seems this caused an increase on the system voltage to about 30V at which stage the battery shut down. It's uncertain wether the voltage kept raising on the system, but a lot of equipment/PCB's are damaged / fried. The issue is really serious so the insurance company flew in an electronics expert to help solve the root cause.

I'm wondering if anyone has some knowledge on this issue where voltage increases because of multiple chargers charging at the same time.

Some details:

  • LiFePO4 bank of 840Ah, full system is designed for 500A, cells are 280A, charging capacity at 1C is 840A, we max out at about 250A which is 0.3C
  • Equipment: Quattro 100A, Skylla 100A, Prestolite alternator + WS500 downsized from 100A tot 75A
  • There is no CANbus connection in place, so everything just runs on the voltage settings.
  • There is also a Sterling alternator protection device installed.


MultiPlus Quattro Inverter ChargeralternatorSkyllaovervoltage
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2 Answers
sherman avatar image
sherman answered ·

Hey there, I have just installed a similar system.. a wakespeed ws500, a Skylla a muliplus all charging a 12V, 1120AH Lifepo4 bank. How did you make out with your sailboat? Did you find a solution to safely charge your bank with all the chargers simultaneously? Best regards,

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chloepeters avatar image
chloepeters answered ·

  1. Voltage regulation: It is crucial to have proper voltage regulation in place to prevent overvoltage scenarios. Since you mentioned that there is no CANbus connection and everything runs on voltage settings, it is important to ensure that the voltage settings on each charger are properly configured and coordinated.

  2. Compatibility: When adding new components, such as the Wakespeed regulator, it is essential to ensure compatibility with the existing system. Verify that the regulator is suitable for use with your specific alternator and battery setup, and that it provides appropriate voltage regulation to prevent overcharging.

  3. Load sharing: When using parallel chargers, it is important to ensure proper load sharing between them. Imbalances in load sharing can lead to voltage variations. Check the configuration and wiring of the Quattro and Skylla chargers to ensure they are functioning as intended and distributing the charging load evenly. MyBKExperience Survey

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