alternator advice please

[Robo-van]

Hi,
I need some advice on upgrading my alternator.
It caught fire today, & I broke down on Friday and had the RAC out.
My battery wouldn't start the van, but the RAC said the alternator was putting out the correct charge.
I understand that a standard alternator in a 2L swb80 petrol transit is for a 12v 55Ah 540A battery.
I have a Ardvark duel charging system on my van, with the following.

1 x 12v 60Ah 600A battery and
1 x 12v 60Ah 640A battery to run all my adaptations.

Can anyone advise me on what size alternator would be best to charged the two batteries please?

Thanks
Chris

[MrMPuk]

The standard alternator will charge anything! You may well be able to get an uprated one but haven't seen any for a while.

[Gunslinger]

you could try interogqating your local ford parts dealer, and then your local motor factors, ask them if there were different alternators fitted if you had different options at buying, like air con (not sure if that was available) because those sort of things might have resulted in a higher output capable alternator

[Terry]

If the breakdown man said the alternator was supplying the correct
output why are you looking at upgrading ?, surely the (starting)battery
is the problem !, I would get it drop tested.
Usually with a dual charging sysyem/relay, it charges the vehicle battery
till 'full' then diverts the charge to the auxilliary battery, then reduces the
charge level needed to keep both topped up !

[stevew]

Can you not fit the 90A alternator from a diesel? I don't know perhaps the brackets are all different, you'd probably need a belt capable of transmiting more power.
I'm in a similar situation. I have two batteries with a split charge relay, at least I already have the 90A diesel alternator. This system sort of works I'm rapidly coming round to the idea that the best option might be two alternators. I was lead to beleive by an ex mechnic friend of mine that this was an option, has any one seen this? I can't imagine where it would fit.
Steve

[rover]

@stevew.

I have never seen a vehicle with two alternators fitted, thats not to say that there arent any of course....but it must be very very rare if there are.


@rob. I dont know where in the East mids you are but if you are in any doubt you need to go and talk to 'Bill Whyatt' in Stapleford, there is nothing they dont know about vehicle electrics, they also recondition alternators and starters.

[Luke]

yours is pinto innit? robo?
i fitted a sierra/granada ghia one to mine thats a higher output but it has the twin pulleys for the powersteering - but i just used one pulley off it!!

[Luke]

actually thinking about it i may have had to alter the bracketry abit!
damn memory

[rover]

Cos I do a lot of jump starting etc I got Whyatts to build me a 70ah version of my original, I would think that would give you any extra you may need.

[baconsdozen]

Twin dynamos and later on alternators used to be fitted to hire boats (cruisers) years ago.They were soon abandoned when reliable split charge relays became more readily available.I'd have thought a standard alternator would be perfectly capable of charging the batteries referred to in the original post.

[MrMPuk]

My old works van used to have a 55v volt alternator to run an automate weldset, it was mounted down low on the opisite side of the engine to the 12v alternator. Was a tight squeeze though.

[Gunslinger]

that was my thought exactly when he said two alternators ..... my mind was saying "external power take-off for inverters"

actually thinking about it i may have had to alter the bracketry abit!
damn memory

memory my a*** .... old age more like

[Nighthawk]

There was an option for twin alternators in the SVO package for front line ambulance.

The second unit was a monster at around 200amps iirc, it lived down below where your power steering pump is, and it was driven by a much thicker belt, you'll also need to replace the power steering pump with the SVO option as that was also driven off the thicker belt.

in years gone by i've seen some inverter systems running the second alt in the same position, but driven off it's own belt.

The main crank damper can be extended by bolting another pulley to it.

[stevew]

Yes the standard alternator should be good enough and split charge relays are reliable. However I'm looking for something a little more high-tech than just connecting both batteries together as soon as the engine starts! I've heard loads theories about what actaully happens in a split charge setup but I just can't get away from the fact that when the aux battery is very flat (quite often the case) the alternator has to work very hard and the main battery is dragged down. There is a possibility that if you start the engine and then stop it in a short space of time when the aux battery is flat it could have taken enough from the start battery to take it below a starting charge. Maybe....
OK so it's never happened to me but I'd still like to avoid it!
Fancy alternator controllers deal with this by only connecting the aux battery once the start is fully charged or at least by having a delay. This also helps extend the life of the alternator / belt. The price of these systems makes fitting two alternators seem quite attractive. And you'd have the additional benifit of redundancy, if one alternator failed you could always bodge it in the field to run from the other. Most importantly for me is that you can set the second alternator to charge to a voltage appropriate to your auxillairy battery which will probably not be an open lead-acid starter type (which alternators come setup for).
Steve

[Terry]

If your flat aux battery is dragging down your start battery , there is something wrong with the split charge relay.
Seems to me you are overdoing the 'redundancy bit, you'll
finish up taking 2 vans everywhere !