Upgrading Alternator

[jonbowen]

This question seems so simple, nobody seems to have got round to asking it before:
I have a 1983 1.9 petrol T25 converted caravelle. After camping up for a few days and running down the leisure battery, then running the van for a couple of hours, the starter battery is discharged ... turns out the alternator is not providing enough current to run the lights + wipers + blower + charge leisure battery (yes, it was a lousy summer), so the starter battery discharges into the leisure battery ... or something like that. I've checked out the electrics v. thoroughly, no shorts or current drains or anything like that.
Anyway, it's got a 45A alternator which is getting a bit long in the tooth. The later models had 65A alternators as standard. Can I just buy a 65A alternator for a 1985 T25 and replace the old 45A one? Will it fit without modification? Should I upgrade the wiring if I do?
Many thanks - Jon

[Mocki]

if this was me, the first thing i woulod do is take the leisure battery off, and charge it with a mains charger, then check the voltage, then leave it 24hrs and check the voltage again........

then while that was happening i would be checking the output voltage of the alternator......... should be between 13.0 and 14.0v ish at the battery

if you do need another alternator (and 45Ah isnt very much) got for a 90Ah off a 2.1 .

Your 45Ah one will have a 3pin plug connection, all the others (65Ah and 90Ah) will be a single bolt connection and a small bolt connection for the blue wire, so you will need to convert the van loom.
Chances are you will be needing to change the pulley as well , if you buy a new 90Ah one, as they now seem to come with the derv pulley on them.

Your problem sounds to me like the split charge is leaking, as the two batterys should never be connected unless the engine is running, although 2 hours is never going to be enough to charge either a fully flat leisure or main battery, never mind both.

I always add a switch to the signal wire for a split charge to make it possible to switch the split charge off to make sure the main battery gets fulll charge in winter months when using lights and wipers and heaters on shirt journeys - give it half a chance of topping up.

[hercules]

This question seems so simple, nobody seems to have got round to asking it before:
I have a 1983 1.9 petrol T25 converted caravelle. After camping up for a few days and running down the leisure battery, then running the van for a couple of hours, the starter battery is discharged ... turns out the alternator is not providing enough current to run the lights + wipers + blower + charge leisure battery (yes, it was a lousy summer), so the starter battery discharges into the leisure battery ... or something like that. I've checked out the electrics v. thoroughly, no shorts or current drains or anything like that.
Anyway, it's got a 45A alternator which is getting a bit long in the tooth. The later models had 65A alternators as standard. Can I just buy a 65A alternator for a 1985 T25 and replace the old 45A one? Will it fit without modification? Should I upgrade the wiring if I do?
Many thanks - Jon

iv just got my 90 and update it 2 a 120 Alternator much better but it was chep doing it for sure as it all new again

[kevtherev]

I have to agree with mocki.
the alternator is well up to the job

I had a 45 amp in my T25 ran all kinds of gadgets worked a treat . Now I had a problem with the split charge relay, it was sticking on, so that meant the leisure side of things was drawing from the starter aswell.

disconnect the starter and see if the van starts off the leisure battery
and do the checks mocki suggests

the first thing i would do is take the leisure battery off, and charge it with a mains charger, then check the voltage, then leave it 24hrs and check the voltage again........

then while that was happening i would be checking the output voltage of the alternator......... should be between 13.0 and 14.0v ish at the battery

[syncrosimon]

Get a Sterling alternator manager and then your standard alternator will charge both batteries handsomely.

This is mine, with optional display panel showing the standard 17 year old alternator (90amp) pushing out 100 amps, 90 into the leisure bats, and at an amplified 14.8 volts to avoid furring.

[IMG1680]http://i199.photobucket.com/albums/aa28 ... 040691.jpg[/img]

It quite simply is the best charging system. we only use a hookup if it comes free with a CL.

[Mocki]

and where might one purchase one of these ?
or more to the point where wouold i find a circuit diagram??

[syncrosimon]

From Sterling
http://www.sterling-power.com/products-altbatt.htm

Need some phat cable to deliver 100 amps though.

[IMG1680]http://i199.photobucket.com/albums/aa28 ... 040621.jpg[/img]

Really very simple to fit as just goes between the alternator and the batteries, when switched off works like a very large split diode relay, and still charges the batteries.

[IMG1680]http://i199.photobucket.com/albums/aa28 ... 040620.jpg[/img]

[jonbowen]

Thanks folks for your contributions. I did all the obvious tests - put an isolator switch on the starter, and then on the leisure, but no evidence of current drain or battery damage on either. At first I thought it was the split charge relay sticking on, but the starter only drains while the van is actually running. If I leave it standing with leisure battery low, no problem, but as soon as I run it, the starter drains ... the alternator powers lights, wipers and blower OK, but then add the DVD player and gas heater and the voltage at the battery goes right down. At first thought it must be resistance of the cable or terminations, but have wire brushed all terminals etc. Helped a bit, but not enough. I'm sure it's possible to recondition the 45A, but for an amateur like me it would take hours to find the bits and do the work, and I can pay for a new one out of 2 hours overtime! Since a new 90A alternator from GSF is only £4 more than a new 45A one, I'll pop a 90A on.
I like the idea of a switch on the split charger - might solve difficulties in the winter, the battery's always low from Oct to Mar. When Mocki says I'll have to "Convert the van loom", that's just putting new terminators on the wires, right? If I need to do/know anything else, please tell me!!
thanks again, everyone, Jon

[Mocki]

"Convert the van loom", that's just putting new terminators on the wires, right?

basically, yes... both thick wires to the big bolt, and the tin blue one to the small bolt...

[R0B]

syncrosimon.how much did your sterling set up.cost you...

[syncrosimon]

The basic unit is 250 quid. It really is good, and can charge 150amp/hr of batteres to a reasonable level in an hour from flat.

The alternator can manage about 60amps at tickover, and I have seen 114 amps output when we were in Corsica and hadnt moved the van for three days with no hook up. It has a temp sensor on the alternator and the batteries so that it does not overcook either. It tells me when the batts will be 100% charged, but I just look and see what amps it is putting in the domestic batteries. The benefit is that it will put in 100 amps for 20 minutes then drop right down, so you can survive free camping or without hookup without having to use the engine very much.

The starter batt always takes priority, so when you put the lights on, it drops the amps to the leisure batts to give more to the starter.

I am gonna wire the vehicle fuse board through the leisure batts, so that starter batt does just that, and nothing else. Also then the headlamps will be getting 14.8 volts which should brighten them up.

It is expensive, but we do save a bit by not having to use campsites, and not needing hookups.

It does have a hookup though, and an 800w inverter, but we only use the hookup for the electric overnight heating, the toaster and kettle, during winter months.

[syncrosimon]

basically, yes... both thick wires to the big bolt, and the tin blue one to the small bolt...

This is the back of the 90. I think it is an M8 bolt which is 5mm in diameter (iirc) when you get the terminal.

[IMG1200]http://i199.photobucket.com/albums/aa28 ... 040618.jpg[/img]