On 16 Jun, 13:17, "Dave Plowman (News)" wrote:
In article . com,
Weatherlawyer wrote:

On Jun 10, 7:45 pm, JohnW wrote:
JohnW, in article MPG.20d64a3e509a9bbb9897f8
@news.aaisp.net.uk, says...

You'll need more than 12v if they are sealed lead-acid,

http://preview.tinyurl.com/2359m9
It looks like the little one he
http://www.maplin.co.uk/images/Full/MM22Y_MM26D.jpg
Thanks.
So which way around do the jacks go? (Assuming I can still find them.)
I've got one of those Maplin's PW0140 Regulator Power Supply jobs the
kind that will work on 3, 6, 9 or 12 volts.

You need more than 12 volts DC to charge a 12 volt battery - a fully
charged 12 volt lead acid is officially 13.2 volts (2.2 per cell). The
rule of thumb figure is 13.8v to charge one. But like all chargers it's
the current that really matters.

You can make battery chargers - but like all such things can usually be
bought cheaper than the retail cost of the bits.

But if you or anyone else wants to have a go I have some pukka 5 amp 12
volt charging transformers designed for the job - all you'd need is a
rectifier and possibly a means of limiting the maximum current. I got a
crate of them off Ebay along with some other stuff and you can have one
for the cost of the postage.

SLAs have different charging requirement to non-gel cells. They should
not be charged with a car or bike charger. Charging v should be
significantly lower.


NT