Learning about good Battery management/maintenance

[NB Lola]

Hi

 

I need some elp. I need to learn more about battery management as all I use is the SOC bit of my Victron monitor. I have no idea how to change batteries out nor recognise which one of my three leisure batteries is currently unwell and why. I know one is unwell because those that know told me after my alternator of five years of age failed recently and had to be replaced - cheap Chinese made crap I was told. Anyone out there near kings Bromley marina prepared to pop over, or in, on a weekend any give me some much needed practical instruction?

Edited October 16, 2016 by NB Lola

[Tony Brooks]

I can't help with popping over but would if you were nearer to Reading.

 

What I can say is there is every chance that all three batteries are badly sulphated. Your Victron monitor has three readings that are normally accurate and two that often tell lies unless the owner really knows how to set up and use the thing. I am afraid The SOC is one of them so I suspect long term undercharging despite what the monitor may try to tell you.

 

If the ends of your batteries have bowed out then its an indication of bad sulphation and you will only have tiny fraction of the batteries capacity left.

 

The volts reading is accurate and useful, as is the amps. The amp hours out is also OK but is of limited use on a day to day basis.

 

Keep charging until the ammeter has dropped to something like 1% of the batteries capacity, however you do not know what that actually is so keep charging until the amp reading stays steady for an hour or so and no longer gradually drops.

 

Charge again when the batteries give a voltage of about 12.2 to 12.3 volts with no loads running.

 

All the above can be confirmed by reading previous threads by other people.

 

As for finding which battery is faulty its difficult without knowing what type of batteries they are. Whoever told you one was faulty shoudl have also told you which one and why. if they did not suspect bovine excreta. In any case it is poor practice to change single batteries in a bank because if one fails another one is likely to soon follow and if it does it can damage the new battery.

 

Indication of a failing battery:-

 

ends bowed outwards

 

When charging individual cells gas far more that the others, bad smell from certain cells, battery gets hotter than the rest.

 

When off charge individual cells dry, cloudy acid.

 

HARD LUCK IF YOU HAVE SEALED CELLS

 

Having charged the batteries, disconnected them all and left to stand for several days - if one battery then has a lower voltage than the rest it is faulty.

 

Based on battery performance:

 

Long time to charge but discharges faster than it once did - short in one or more cells, see above.

 

Short time to charge and a short time to discharge - badly sulphated - lost capacity.

 

Hope this helps.

 

 

 

 

Edited October 16, 2016 by Tony Brooks

[NB Lola]

Much appreciated.