[samste]

Battery is DiaMec 4.2 Amp Hour 12 Volt. Jaycar Cat No: SB-2484 (Sealed Lead Acid Battery)
Charger is 12V 350mA Jaycar Cat No: MB-3517

Paul

Hi Paul.

Unfortunately the way they label them is mis leading.

You will only get 4.2amps out of the battery for 1 hour if you are lucky, normally 90% thus approx 3.8 amps
The reason for the 20 amp hour label info is that they say the battery can deliver with good safe working voltage for 20 hours but at 210ma only (4.2 amps divided by 20)
EG. Alarm system only needs approx 200ma to run off battery back up but the voltage must not drop below a safe level or will cause problems.
normal battery's will deliver the amps but the voltage drop well below desirable levels.

EG. My 22AH Battery will deliver 1.1ah for 20 hours comfortable.
Therefore i could charge battery's drawing 2200ma for about 10 hours so about 10 battery charges. But i expect probably only will gives
me 9 x 2200ma battery charges

So that battery 12v 4.2amp in theory could give you two charges of 2200ma battery's and then be flat.

Some info

http://www.powerintratech.com/lead-acid-...12-4.2.gif

http://www.jaycar.com.au/images_uploaded/recharge.pdf