possible battery charger problem

kashurst

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I have a Mastervolt MASS 12/60 battery charger. It has a LED dispIay indicating when its charging, floating etc. All appears to be OK but.....
I'm not 100% convinced its working properly. I usually leave the boat with the charger on while I am away possibly for 3 -4 months at a time. I have done this on all my previous boats no problem. Last autumn came back to the boat to find the 2 year old engine start batteries, knackered and very low on acid. Could just be bad luck/poor batteries that came with the boat or maybe the charger has cooked them. Replaced the batteries and when I went home, turned off the charger and isolated the new batteries. Back at boat this week, turned everything on batteries all perfect, turned charger back on.

Watching the volt meter today as I was doing a few jobs, I noticed the battery voltage varies from @ 13.4V (ish) up to as high as 14.5V. I have checked the volt meter and it reads correct. The 14.5 V seems too high to me. Is this normal with this make of charger or other makes of charger? or is something amiss?
 

A_8

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It should go up to 14.5 or even 14.8 but as soon as the battery is fully charged it should go down to 13.2 ish. If it does not this will indeed break your batteries.
 

Lon nan Gruagach

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I have a Mastervolt MASS 12/60 battery charger. It has a LED dispIay indicating when its charging, floating etc. All appears to be OK but.....
I'm not 100% convinced its working properly. I usually leave the boat with the charger on while I am away possibly for 3 -4 months at a time. I have done this on all my previous boats no problem. Last autumn came back to the boat to find the 2 year old engine start batteries, knackered and very low on acid. Could just be bad luck/poor batteries that came with the boat or maybe the charger has cooked them. Replaced the batteries and when I went home, turned off the charger and isolated the new batteries. Back at boat this week, turned everything on batteries all perfect, turned charger back on.

Watching the volt meter today as I was doing a few jobs, I noticed the battery voltage varies from @ 13.4V (ish) up to as high as 14.5V. I have checked the volt meter and it reads correct. The 14.5 V seems too high to me. Is this normal with this make of charger or other makes of charger? or is something amiss?

Is the voltmeter connected directly to the battery terminals with its own wires that are used by nothing else whatsoever? Of not than all bets are off.
 

kashurst

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the voltmeter is on the circuit breaker panel - however I have measured the battery voltage at the battery terminals with a DVM and the readings match.
 

Mr Googler

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On my victron absorb mode is 14.5 (banging in charge), float is 13.8v (still charging but getting near full) and storage is 13.2 but usually around 13.3 or 13.4 on the meter. I think it kicks into storage after 12 hours at float.

What I have found is if something is pulling amps from the batts, the charger might not change modes especially float to storage mode. With everything off, it will normally go into storage ok when I check the next day.

Another battery in the bank could be poor and that could keep the charger banging in the amps to all. I think the way to test is leave them standing off charge for a bit, disconnect from one another and read the voltages across the terminals to see if they are much different from one another. I am however no expert...just what I’ve seen or read on here really.
 
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