Thread: Second alternator on Disco

I have fitted 2 alternators in an RRC 3.9 and have 2 separate systems.

Why, because the second alternator will charge the second battery much quicker than when the poor old alternator is trying to also run aircon etc etc. You also have a backup alternator in case the first alternator dies, as mine did in Kakadu. All you do is pull the wires of the first alternator and bridge the + of the batteries. I also have provision to run spots from the second system to balance the load a bit.
The only difference to what you are talking about is that I have a relay controlling the ign light, and I have the light inside on the console , so that it comes on with the ignition and goes out when the alternator charges.
I now also have fitted an ABR dual battery controller through a 60/80 amp NC relay, so that the batteries are connected down to 12.4 volts, then disconnect.
I have an ignition on wire to the relay trigger that switches the relay to the unconnected B when the ignition is turned on. The batteries reconnect from the surface charge of the starting battery being above 13.2 when the ignition is turned off. They then stay connected until the starting battery is down to 12.4.
I hope to have the Engel run several more hours with this.

Just in case I just bought a 120W folding solar panel, so the sun will not shine in Queensland for the next 2 months.
Regards Philip A

that sounds like a well thought out system. have you had any faults with the relay insted of just a globe ?

that sounds like a well thought out system. have you had any faults with the relay insted of just a globe ?

No, I have had no problems.
If you do not have a relay the light will be on all the time, and although they only draw 4watts , this will flatten the battery over a few days.

All cars cut off this circuit with either the ignition switch or a relay.
All you have to do is find a ignition on circuit to trigger the relay.
In my case there is one near the LH battery which I think is an unused headlight adjust circuit.
Regards Philip A

Originally Posted by team_little_legs

and just a second set up for winching and running my stereo

its a big stero gotta have some rediclues bass when your up the bush

Originally Posted by PhilipA

No, I have had no problems.
If you do not have a relay the light will be on all the time, and although they only draw 4watts , this will flatten the battery over a few days.

All cars cut off this circuit with either the ignition switch or a relay.
All you have to do is find a ignition on circuit to trigger the relay.
In my case there is one near the LH battery which I think is an unused headlight adjust circuit.
Regards Philip A

Silly/uninformed question? Could you not just fit a better alternator?

Hi all,

anyone got pics of dual alternator install ?

prefer D1 tdi but any other install i am interested

regards
OZ

Silly/uninformed question? Could you not just fit a better alternator?

Mine was on a V belt V8 and a V belt will not run more than 85 amps reliably. In fact in 93 LR bought out a hybrid( Heath Robinson) sytem of a multi rib for the 85 amp alternator and V belts for the other stuff. If you listen to a GQ Patrol you will often hear belt slip and they have 2 V belts running their 120 amp alternator.
My first alternator was an 85 amp Bosch and the second an 85 amp Ingram.

Short of changing the whole front of the engine IMHO the 2 alternators are the best sytem.

Is this a record for a late reply???

Regards Philip A