Charging batteries with specific needs

[Bazza Senior Member Find all posts View Profile Close Bazza]

My son is looking to replace his auxilary Battery in his GQ and can get hold of some near new big wet cell batteries rated at 150amps. These were used as "back-up" power for various esential equipment ( alarm systems, evac system, diesel/electric pumps, gen set, ect ...... ).
The only issue I see is that they are all marked as "max. 40amp charge". Would this make them not suitable for his purpose as the charging amp rate in the GQ would be much higher than 40amp and therfore destroy the battery?
Bazza

[LeighW Avid PP Poster! Find all posts View Profile Close LeighW]

The charging rate out of your typical GU should not cause any problem, it may exceed 40A for a short time but won't stay at that rate for an extended period.

If you are really concerned you can manage the maximum charge rate by careful selection
of the cabling diameter between the charge source and the aux.

Cheers,

Leigh

[sweetpea Senior Member Find all posts View Profile Close sweetpea]

My son is looking to replace his auxilary Battery in his GQ and can get hold of some near new big wet cell batteries rated at 150amps. These were used as "back-up" power for various esential equipment ( alarm systems, evac system, diesel/electric pumps, gen set, ect ...... ).
The only issue I see is that they are all marked as "max. 40amp charge". Would this make them not suitable for his purpose as the charging amp rate in the GQ would be much higher than 40amp and therfore destroy the battery?
Bazza

If the GQ alternator is the standard 75Amp alternator that was in the GQs I had I would be very surprised if the output exceeded about 45 Amps down hill with a tail wind.

Make sure the batteries are made for motor vehicle use. If they are batteries made for stationary use the may fail with the heat and vibration under the bonnet.

S.

[winniliss Avid PP Poster! Find all posts View Profile Close winniliss]

Excessive charging current with high engine bay temps will shorten the life of these batteries by the sounds of it but time will tell. Keep an eye on battery temp, not boiling the acid etc.

Winston

[D4D Addicted PP Member Find all posts View Profile Close D4D]

I'd suggest the battery plates will fall apart long before the battery is damaged from over charging. Sounds like the batteries are designed for permanent installation not bouncing around under a bonnet. YMMV.

[Bazza Senior Member Find all posts View Profile Close Bazza]

Thanks guys.
These batteries are designed for permanent installation but they are built very strong and look very similar to the big black CAT batteries. Two of them were being used as starter batteries on a large diesel gen set but were being charged by a 40 amp 5 stage charger. I think their probably robust enough but I was concerned about exceeding their posted charge rate for prolonged periods. I'm not paying for them so I suppose it's worth trying them out before going on any long trips. I think he will be putting them in the rear of his GQ in an externally vented box, as they are heavy buggers. It takes two guys to lift one of them comfortably.
Bazza.

[Bear63 Senior Member Find all posts View Profile Close Bear63]

When they are saying maximum 40 amp charge they are referring to the chargers that have a manual over ride that some people use to crank the amps right up to wack some charge in fast , don't worry about the patrol overcharging them it wont happen , the alternator isn't designed that way