Charge a 6V battery with a 12V charger?

[erick (Eric)]

Yes, John. I also saw a combined 6V/12V charger and 4A 12V power supply in the Autobarn catalogue last night - $89. If I was starting with nothing, I'd have one of these - it would do a number of tasks for which I have separate units.

But I do now have a 6V battery and 6V charger - I'll connect up this weekend (when I can get a power plug to fit the camera. Looks like I'll be carefully drilling out the one I bought ).

This has been an interesting exercise together with my other thread on AA batteries and better chargers. I've learnt a lot. I had heard the term "trickle charge" but had thought that charging was not much more than stuffing current into a battery until it was "full"! There is clearly much more to charging batteries than that!

I've realised my 12V charger is a "stuff it in @ 3A" type charger and I should be careful not to overcharge my gel batteries. No more leaving them sit on the charger overnight, but rather remove when that green LED comes on.

[Paul Hatchman]

Originally Posted by erick

I've realised my 12V charger is a "stuff it in @ 3A" type charger and I should be careful not to overcharge my gel batteries. No more leaving them sit on the charger overnight, but rather remove when that green LED comes on.

Hi Erick,
Is it a standard car-battery charger? If so, go and grab yourself an intelligent charger with a gel cell setting if you can afford it.

Gel batteries need to be charged at a lower voltage than wet cells to prevent them from outgassing. Since there is no way to replace the outgassed hydrogen in a gel cell, you're going to shorten the life of the battery.

[erick (Eric)]

"an intelligent charger with a gel cell setting if you can afford it."

Thanks - any recommendations?

[Starkler (Geoff)]

Originally Posted by Paul Hatchman

Hi Erick,
Is it a standard car-battery charger? If so, go and grab yourself an intelligent charger with a gel cell setting if you can afford it.

Gel batteries need to be charged at a lower voltage than wet cells to prevent them from outgassing. Since there is no way to replace the outgassed hydrogen in a gel cell, you're going to shorten the life of the battery.

Indeed gel cells require different handling to wet cell lead acid batteries.

Nominal trickle voltage is 13.8V for wets and 13.65V for gels. You can boost charge wets at 14.4V I think. Doing the same to a gel is very inadvisable.

[Paul Hatchman]

Originally Posted by erick

Thanks - any recommendations?

Hi Erick,
As always, it depends. But for charging a range of smaller lead acid batteries, the name brand chargers are Xantrex and CTEK. Both provide high quality multi-stage chargers and I believe both brands are available from Battery World. The CTEK XS800 is about $90 or the next model up, the XS3600 is $140.

Jaycar have knock-offs of the CTEK range e.g. This one would be equivalent to the XS3600 http://www.jaycar.com.au/productView...T&SUBCATID=295. I'm not sure how well the Jaycar ones actually work, and unfortunately they don't have a seperate "gel" charging mode, but claim to be able to charge gel batteries correctly. I have both a Xantrex for charging my batteries at home and a Jaycar CTEK knockoff which I take with me to Wiruna.

Cheers.

[erick (Eric)]

Thanks Paul.