3 Posts - Page: 1

DIY battery charger

So I am building an alternator powered battery charger for when I cant wait for a normal charger to work.

I have an electric motor mounted up to an alternator in a cage. The intent is that I can clip on the battery leads in the flat battery and charge it like the motor is running.
Its fully self contained, so should not upset the car the battery is in.

Now I have some questions about the wiring.

B+ goes to the battery positive. in this case its got a jumper cable with a clamp connected to it.
D- goes to the chassis earth/battery negative
D+ goes to ??
DF goes to the warning lamp (I think)

I also want to wire in an amp gauge so I can see how many amps are being pulled across.
Normally, one side of the gauge goes to the battery and the other side to the ignition switch. I don't have an ignition switch so I assume that it just goes back to the same positive terminal the other post connects to.

Any suggestions?
If it gets too tricky, i have another internal reg alternator from an E series that i can use that seems to have less wiries

Back view of the setup

back of alternator
B+ is to the left with the larger cable attached to it
B- is to the right. You can just see it connected to the frame/earth lead
At the top is the the T-style connector. at the top is the D+ and underneath is DF.

Bottom of the amp memter
Two posts. One is marked (-) the other is marked (+)
It seems that the alternator that i was using, despite it looking like an internal reg unit, is in fact an external reg unit from an early holden gemini/torana/kingswood.
Moved on to a mitsibushi alternator, that is labeled internal reg, so Im sure its an internal reg unit.
Part number A2T2497 23100 H711 12V50A
 I think this came from an E series motor but Im not sure.
Cant seem to find much on these alternators, except fopr a french ebay site selling the modern replacement unit.

Mitisubushi alternator
The two wires in the T-plug. The bottom spade is labeled "L", which I assume is for the lamp/load/charge light circuit.
What does the top spade terminal go to?
The third alternative is to use a 120amp prado alternator that is brand new. Its from my dads prado. When I repacled his dead one, we got given the wrong unit, so they replaced it with another and never asked for the old one back.

These units have 3 wires out the back plus the B+ post.
They are labeled as (top down in the pic)
Warning lamp. - This to the warning lamp globe. the other side of the globe to 12V positive.
Ignition - I guessing that this can go to 12V positive somewhere. I could just hook it straight to the B+ terminal as this connects to the battery anyways.
B+ sense - ??
You can see the B+ post on the side of the alternator.
3 Posts - Page: 1