question

hogspogs avatar image

Centaur Charger not outputting absorbtion/bulk voltage

  • Centaur 12/60 charger
    • DIP switch set to AGM (off | on | off)
  • BMV712
  • (3) Firefly Oasis G31 (348 Ah)
  • ~25 ft 1/0 cable run (one way)

I am not seeing bulk voltage on my bank when charging. I am seeing over 50A output on the Centaur charger itself as well as the BMV 712. However the voltage only gets up to about 13.6 and I am expecting to see 14.2V. Is there a problem or is this fine since the bank is drawing plenty of current?


MPPT - Solar Charge Controller
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2 Answers
Justin Cook - Bay Marine Supply USA avatar image
Justin Cook - Bay Marine Supply USA answered ·

Hi @hogspogs, welcome to the Community!

What you're seeing may just be the effect of voltage drop over that long of a run; 50' round-trip distance at 12v and 60A on 1/0 cable = ~2.51% voltage drop (this depends additionally on several other factors, such as the type of cable, number of conductors, quality of crimps, type of fuses or breakers used, quality of connections, and etc.)

If we round up to 3% drop to account for a few less-than-ideal conditions, 14.2v turns into 13.774v, which is awfully close to what you're seeing.

Although this is likely okay, you can check all of your connections and crimps to be sure they're tight and good, make sure your fusing or breaker at the battery is good and known-brand (ie, Bussman, Littelfuse, Zeeman) and, if nothing else, size up to a heavier gauge. 50' is a long way for 12v to travel!

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hogspogs avatar image
hogspogs answered ·

Thanks for the thorough reply Justin. What you're saying makes sense to me. I used all blues seas buss bars/terminals/fuses, ancor marine grade tinned cable and decided on the 1/0 AWG cable from the Critical Voltage section of the chart here:https://www.bluesea.com/resources/1437

I have a boat friend who always says "go one bigger", I should have heeded his advice :)

Do you think that the lower voltage seen at the battery terminals while charging will have a detrimental effect overall on the battery life or ability to reach 100% SOC?


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