Three cheers for Solar Charging!

[xpress]

these batteries have been left standing in the garage.

readings before charging:

assuming 12.8 is very good after charging and standing. let's see what these say a few hours after a good charge.

starting at:

Ultra: 5.15v = not a good start. i would say ready to go to car battery heaven.
Pavilion: 12.14v = promising, let's see what it holds after a full charge and a stand.
Varta: 12.03v = she's been temperamental but i am going to try a different battery charger on her.

is there anything i can do to the ultra to raise that or is she ready to go to the recycling tip? can i top up the electrolyte? i can take the panels off and it does look like it needs topping up past the rods. i can't see any water.

see you in 24hrs loll with the results.

edit:

connected the pav and the varta up. the pav is reading "charged" on both my chargers, a halfords and rac. going to press ahead and leave it on there and read it after about 12 hours good charging.

[alex_holden]

is there anything i can do to the ultra to raise that or is she ready to go to the recycling tip? can i top up the electrolyte? i can take the panels off and it does look like it needs topping up past the rods. i can't see any water.

It's unlikely to help. The plates in lead acid batteries tend to disintegrate eventually.

just wondering, is it ok to charge up a caravan battery on normal automotive car chargers?

Yes.

[xpress]

how long should i leave them on the charger? and how long to rest before i take another reading?

also, is it safe to touch the batteries with the multimeter and read the voltage whilst charging?

thank yee.

[alex_holden]

how long should i leave them on the charger? and how long to rest before i take another reading?

How long is a piece of string? It depends how much charge there is to start with and how much current the charger can supply. Is it a smart charger that automatically drops to a trickle charge when the battery is full?

also, is it safe to touch the batteries with the multimeter and read the voltage whilst charging?

Yes. The voltage while charging will be a bit higher - maybe 14V or so.

[xpress]

this is interesting, i have this:

says it's 4amp max battery charger and can take a battery max capacity of 55Ah

http://answers.halfords.com/answers/402 ... htm?page=2

it's a Halfords Halfords 1200cc Battery Charger

says charges up to 1200cc car's batteries but it's charged up my bm battery fine.

if the charger says 'charged' i wonder if that means it can charge up a battery any more or that specific battery has reached its limit?

The 1200 cc battery charger Fast charge setting has a max capacity of 55 Ah and Normal charge setting has a max capacity 35Ah. can any battery boffins tell me what stops it from charging a bigger capacity battery?

halfords site states that the 1200cc charger is not enough for a 1900+ cc engine yet it states it will charge a 55ah battery.

in which case the pavilion at 12.14 has reached its limit, but it's been left standing so i don't know why it would show up as charged, maybe it reads all batteries above 12.10 as charged.

not a fan of battery chargers showing their usefulness for cars as measured in cc engine size!

[xpress]

pavilion is reading 12.57 on the charger and 12.54 off the charger. halfords 1200cc charger, possibly trickling?

this one is on a rac charger. the varta 13.28 whilst charging and 12.78 off the charger dropping quickly 12.77 12.76 every second .. i might take this one off when it stays at 12.8

left to stand for a while ..

21:05 - varta is at 12.63
pavilion - 12.37

[alex_holden]

not a fan of battery chargers showing their usefulness for cars as measured in cc engine size!

Yes, it's nonsense. A small charger will charge a big battery, it will just take longer to do it.