Battert Losing Charge

[victoria_5095720]

We have a sprite continental approx 1993 and have recently purchased a new battery but this seems to be discharging very quickly. If the caravan is left for a few days there is no power on the battery gauge, but the sight glass on the battery is showing fully charged. If the caravan is then moved the battery gauge shows full for a couple of days. I am led to believe the caravan has a charging unit on it but am unsure if this is working or if we have a short somewhere, any suggestions and easy solutions would be appreciated.

Thanks

Trevor

 

[rayc]

Trevor, can you explain what you men by "if the caravan is moved"?

Do you mean towed with the 12S socket connected thus charging the van battery from the car?

The first thing to do is to check what the voltage at the battery terminals is when the meter is reading zero.

 

[rob_jax]

Trevor,

A fully charged battery with have a no load voltage of 12.6 volts or possibly up to 12.8 volts. If you have an accurate digital multi-meter it's easy to make this measurement - if you don't have a multi-meter buy one from Maplin.

The battery voltage drops by 0.2 volts for each 25% of charge that's removed: 75% charged = 12.4, 50% = 12.2, 25% = 12.0

Then below 25% the cell voltage rapidly drops towards 10.8 volts - fully discharged and the battery is likely to be damaged if left in this condition.

If the battery shows 12.6 volts and then drops to under 11 volts in 2 or 3 days - then something with a high current draw is switched on - like the fridge.

If the battery shows 12.6 volts and still shows 12.6 volts in 2 or 3 days, but the battery gauge shows empty - then the gauge is probably defective.

Note: Just measuring the voltage is a first round test - if this is OK - then measuring the current is the next step. Certain battery faults can give a full charge, 12.6 volt reading but then not be able to supply any current at all.

Robert

 

[cooky1]

A couple of years ago our battery would not retain it's charge. Even when fully charged on a site it would often discharge overnight. I bought a new battery thinking that the old battery was no good. Problem still there.

I phoned the manufacturers of the charging unit and explained the problem. They said it was a problem inside the charging unit (PMS1 on an Abbey). I sent the unit back to them and they repaired it for about