Does my battery sound okay?

[BigTim]

Some of you may have read my recent, lengthy, post regarding problems with my battery and caravan charger.
I have now replaced the charger/PSU with a new unit and that's working fine.
I have now, therefore, turned to checking out whether my battery has "died", as it was previously unclear if it was the battery and/or the PSU.
Last Friday I removed the 110AH battery from the caravan and put it on charge on my "Halfords" automatic battery charger.
I charged the battery for approx 48 hours after which time the charger indicator light was showing the battery as "charged" and being "maintained" by the charger. The battery gave a multimeter reading of 13.43 volts.
As I know that one does not get an accurate multimeter reading immediately after charging the battey I then left the battery OFF the charger for a further 29 hours. The battery then gave a multimeter reading of 13.09 volts.
What do folks think? Is the battery okay or does the fact that the charge has dropped indicate that it is not working fully?
I'd be grateful for comments before I decide if I need to replace the battery. I rely on the battery to power our Powrtouch mover to get the 'van up our steep drive - it's, also, parked "nose" in so the mover is essential to get the 'van out.
Thanks in anticipation.
Tim

 

[wattie]

Hi Big Tim.
I had problems with battery recently looked up phone book and luckly there was an industrial batteries
supplier +manufacturer I bought a 125 amp battery and can take 100 amp discharge for 5 hours.
The supplier said a lot of leisure batteries have plates not much thicker than car batteries.
Away recently at a C.S. lasted six days before recharge.
cost £90+vat.
Wattie.

 

[Whittakerr]

Wattie
Don’t quite understand what battery you have got! You said it’s a 125 amp battery. Do you mean 125 ampere/ hour battery, which will mean it is capable of supplying 125 amps for 1 hour.
You also state it can take a 100 amp discharge for 5 hours which would mean it’s a 500 ampere / hour battery. I doubt if this is the case as it wouldn’t fit into any battery box I’ve ever seen and would be extremely heavy.

 

[Steve L]

Hi Tim.
Your battery sounds like it is holding charge. But using a leisure battery for a mover is asking a lot of the battery as leisure batteries are designed for a light electrical loading over a long period. Whereas a car battery is designed to cope with heavy loading for a short time.
To check your battery for lack of charge hold, chrage it as youve already done and leave it for a few hours. measure the voltage with your multi meter. Then connect an average power demand such as a 55W headlight bulb (H4) to the battery and measure the voltage drop. If the volts immeadiately drop below 10 volts, your battery is faulty due to buckled or broken plates inside the battery.

Unless your not competant at reversing your caravan onto a pitch, I don't see the need to use a mover away from home base. I say this because generally folks who keep their vans at home or in a storage facility generally are parking in a very tight space with only inches to spare and need a mover to provide motive power with finesse. So if that's the case, I would wire the mover so that it can be connected to a spare tractor battery for home base use and leave the leisure battery to power low wattage lights etc.

 

[ProfJohnL]

Hello Tim,
Your battery results look quite reasonable. Bearing in mind your new PSU is capable of running without a battery, the job of the battery is to cover the very few occasions when the power demand exceeds the PSU's capability - for example in the evenings when lights TV heating fan and waterpump may all be on at the same time.

The rest of the time the PSU recharges the battery ready for the next high demand period.

I suggest you try the battery, and provided the caravan mover works then I don't think you need to worry.

 

[Reg]

Just a thought....... If you do not use the battery for long stays without EHU plus have a mover wouldn't a car battery be more suitable?

 

[ChrisUK]

You say the volts went up to 13.34 on charge, then 13.09 off charge, this is normal. In fact the off charge value is a little high, I would have expected arround 12.6 to 12.8 depending on temperature.
I believe the effect is known as something like "float charge" and the battery has to settle after being charged to give its true state.

 

[grambo62]

Hi, wet batteries are rated not in how much power they discharge per hour but what is called the Cold Crank Amps CCA. This is the amount of power the battery will use to turn an engine over from cold. So hence the load characteristics on a heavy duty battery will say 500amp to over 750amps.
It is also better to buy a battery that needs regular toping up of water (not the sealed for life types). This is mainly comes down to good care and maintenance, and will prolonge the life of the battery.