Altenator upgrade?

It depends if you really have to charge your dead flat 120 amp battery in one hour.

If you have to do this, it would be essential to have the alternator capacity.

But if you have say 55ah alternator, your AGM would charge from half flat to full in about 1.5 hours or a bit less of driving/fast idle. If you are using more than 60 amps out of your battery in a short time I would say you probably need another battery rather than a bigger alternator capacity.

Hi Uncle,

I have a 120ah alternator now, as my original one died on me. I had already had it repaired twice before, and gave me heaps of trouble when a long way from Coober Pedy, only to die as I reached the caravan park. I decided that when I returned home it was time to replace and the auto elec recommended the 120ah. I am glad I have done this, as it now works on charging three batteries, two in the vehicle and one on the camper. The extra grunt makes life easy when bush camping as I do not have to run the vehicle too long to recharge the aux batteries.

Cheers

Glenn

I haven't but plan to some time in the future......
This mob are usually unbeatable on price- I bought an alternator off them a few years ago for another vehicle (mate's cruiser)
www.aea.com.au/shopping/index.html

I have heard of alternators supposedly dying prematurely from overheating whilst charging aux batteries- but not first hand.
Cheers

An alternative is to fit a alternator management system (AMS) to enhance the alternator output. The following is an extract from a Merlin brand AMS sold by Bainbridge Technologies

"The alternators fitted to most
vehicles are standard units designed only to
recharge an engine start battery and run a fan,
heater, wipers etc. Therefore, they are fitted with
a fixed voltage regulator designed to maintain
voltage at 14V.
Due to the internal resistance of deep cycle
batteries and voltage drop across split charging
systems; Standard alternators are incapable of
quickly and fully recharging battery banks. The
problem is exacerbated with larger battery banks
and extreme temperature fluctuations.
The AMS is designed to work alongside your
alternator's standard regulator. When required,
it will take over alternator operation to ensure
that batteries receive correct charging voltages
and maximum possible alternator current. AMS is
not a booster (which can damage the alternator)
- it is an advanced regulator that compliments
the alternator and adapts it's charge profile to
suit the needs of the specialist vehicle or cruising
vessel. The AMS ensures that the alternator
continues to work within it's design parameters -
therefore, it won't shorten engine or alternator
life."

Their site link is www.baintech.com.au

No idea how much they cost.

Cheers

Or you could use one of these,
http://www.sterling-power.com/pdf/ab12xx_gb.pdf

Work a treat and optimise what you already have rather than the same shortcomings with a bigger alternator.

Geoff.

I don't know what make of 4x4 you have but check out the link i have done for this subject

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