Battery charging problem

[tonyc07]

Hope someone can help with a possible diagnosis?

Charger connected to shore power, I switch on at panel & hear it start up with whirling of fan; it then goes to boost mode but does not step down to float as charge progress’s. Sometimes switch on from panel and nothing?

When coaxed into start up (repeat switch on / off) charger appears to finish charging after short period – say 3-4 hours - and stops charging – light on panel is on i.e. unit appears to be on but not charging. Looking at the charger - no sign of life? I've put a meter on the AC in terminals and have power.

During charge if I switch on other DC services there is no compensation e.g. lights dim, water pump slows?

Bow thruster and windless batteries charge Ok as does the engine start battery?

Just seems to be domestics not charging properly.

Going out this week end domestic bank not even charging from alternator??

Anyone got any ideas?

 

[VicS]

What is the charger. Make and model?

How is your alternator output split between the two batteries. Diodes, VSR or something more sophisticated, if so make and model?

A diagram of how it is all knitted together would help too.

Maybe a bad connection somewhere in the domestic bank wiring but I dont think anyone stands much of a chance of making a diagnosis without a diagram and more details.

 

[Moonshiners]

batteries topped up? I've had a few things that won't run proper charge cycles if the batteries arn't well maintained.

 

[Mal113]

If your battery charger is charging the other batteries on-board, then I suggest you look at connections to your domestic battery and/or the battery itself. An high internal resistance due to a defucted cell would cause the problem you have noted. try and get a high discharge test done to determine if the battery is OK. Further, if the battery has been left for a long time without charge old batteries can form crystals on the plates that will not allow charging to take place.

 

[tonyc07]

Thanks for the input guy’s.

I’m always on top of the battery maintenance ie keeping an eye on the levels. Last check was only a couple of weeks ago and all was well - ish. The issue has been ongoing for some month or so.

The banks are split by diode – so I’m reliably informed and that they are a robust piece of kit. I’m going to investigate this week end. My gut feel is a knackered battery cell or two OR a poor connection somewhere in the DC circuits. It does appear to be charging the other two battery banks so near comfortable that the alternator works OK.

The AC power to the charger is I believe a possible fault on the pontoon. I have AC – 230v and as explained when firing up additional AC devices on board AC drops to 210v ish?? Seems therefore that there could be a leak to earth shoreside?
Perhaps the charger will not start up if the AC voltage is below 210v?

If anyone has other thoughts please let me know, otherwise I’ll report back next week!

Thanks again