Battery replacment...finally

Hylda&Jon · Guru

Battery replacment...finally

jimricho · Guru

Good news if eventually..... An AGM type battery is a good choice. Without going back to your original post I seem to recall that it was an AGM too, but "sh*t happens" can apply to any battery.

Also note the comments on that post about the need to use a good quality mult-stage "smart" charger with AGM batteries.

Jim

Hylda&Jon · Guru

The battery I replaced was a 'Amp-Tech D876 - 120 amp'. After spending $400 on a new battery I'd be a bit reluctant

to outlay more money to replace a charger that seems to have worked ok for the last 2 years
Cheers
Jon

ozjohn · Guru

I've always used Wet Cell Deep Cycle Batteries and have had good use from them. The current one (110A/H Trojan) has lasted 6 years using a good 3 stage charger.
A friend who has the same battery only got 2 years from his and I put this down to the fact that he doesn't use a multi stage charger. His single stage 8 amp charger jsut keeps caharging at the same rate even when the battery is fully charged. What's it's doing is cooking the battery and significantly shortening its life.
Following all the good reports and info on batteries on various Forums I'm about to update my battery as it will now only hold 11V. (After 6 years)
I'm about to purchase a 100 - 120A/H AGM depending on what fits the battery box I have in the vans boot. I have my fingers crossed that I'll get the same or better service from this type of battery over my previous wet cell battery.
ozjohn.

Peter_n_Margaret · Guru

Hylda&Jon wrote:

The battery I replaced was a 'Amp-Tech D876 - 120 amp'. After spending $400 on a new battery I'd be a bit reluctant to outlay more money to replace a charger that seems to have worked ok for the last 2 years
Cheers
Jon

You could also conclude that your charger COST you $400 by stuffing the battery???
What is it and what are the bulk, absorb and float rates?
And if you can't answer those questions, I would seriously question the charger.

Cheers,
Peter

jimricho · Guru

If the charger concerned is the Projecta 10 amp (or 10,000 milliamp, why do they that, it's like saying the next town is 100,000 metres away instead of 100 kilometres) automatic one, they quote a charge rate of 10 amps RMS or 6.3 amps DC real charge current. The mere fact that RMS is mentioned would indicate a large ripple component on the output that's common on cheaper chargers but that deep cycle batteries, especially AGM and gel batteries do not like. If the output is pure DC the term RMS is not applicable.

having spent $400 on a good AGM battery it makes good sense to go the extra yards to install an appropriate charger or risk shorter battery life and premature failures like you've just had.

-- Edited by jimricho on Saturday 22nd of May 2010 06:00:22 PM

BobnBev · Senior Member

Hi All, We just replaced our 2 ,120amph AGMs .. also put a C-TEK 15 amp charger on them @ $260 odd ,its looking after the batt. and seems to be doing a good job..Im sure the old charger was the problem before..anyhow all good now.. The C-Tek is much lighter and tells you what is going on...Bob n Bev

jimricho · Guru

For 240 ah capacity I would have gone for the 25 amp model but the 15 amp should be fine except it will take more than one night on "ground" power to fully recharge a deeply discharged 240 ah battery bank. You may perhaps have solar and/or be able to recharge from your tug while "on the move" in which case this should not be a problem.

If you find you are getting less than optimum life out of the battery bank I would consider fitting two 240 ah 6 volt batteries connected in series rather than two 120 ah 12 volt batteries parallel connected when replacement time comes around. Hopefully that will be a long way off.