Deceleration Alternator

[Christ]

As I find the time and money, I'm going to be revisiting this... since my '86 Golf diesel doesn't have an ECM, etc, it could technically run with NO electrical load at all!

If I can find a way to do it, I want to remove the electric solenoid from the injection pump, and replace it with a manual shut-off to kill the engine.

Then, rewire the alternator so that it will only charge based on brake usage or battery voltage (in the case that the battery gets low, such as night driving or times when the lights need to be on during the day.)

There's already no radio, so aside from various sensors which turn on lights in the gauge cluster based on specific events, there literally is no electric load beyond the fuel pump itself.

So little load, in fact, that a small bank of batteries will be necessarily placed onboard because the main battery(ies) will likely get overcharged, or the alternator itself will provide no braking effect due to the SOC of the main battery(ies).

[Varn]

If you have a stock alternator system you already have a regulator which only charges the battery as it is needed, ei when the lights or blinkers are on. When the diesel is running there is only a trickle needed for the solenoid. Probably on the order of 1-2 watts (or less than .003hp) I would bet that the booster pump uses something in the magnitude 120 watts.

With the type of driving that I do, I only use my brakes only a few seconds per commute. To get enough charge into the battery the alternator would require lots of energy probably way beyond what the battery would feel comfortable accepting and beyond what the alternator is capable of delivering. Batteries like slow changes in their state. They last the longest that way.

Originally Posted by Christ

As I find the time and money, I'm going to be revisiting this... since my '86 Golf diesel doesn't have an ECM, etc, it could technically run with NO electrical load at all!

If I can find a way to do it, I want to remove the electric solenoid from the injection pump, and replace it with a manual shut-off to kill the engine.

Then, rewire the alternator so that it will only charge based on brake usage or battery voltage (in the case that the battery gets low, such as night driving or times when the lights need to be on during the day.)

There's already no radio, so aside from various sensors which turn on lights in the gauge cluster based on specific events, there literally is no electric load beyond the fuel pump itself.

So little load, in fact, that a small bank of batteries will be necessarily placed onboard because the main battery(ies) will likely get overcharged, or the alternator itself will provide no braking effect due to the SOC of the main battery(ies).

[Christ]

Re: the booster - When I get around to fixing the brakes 100% (master cylinder leaks down) I won't have a booster at all. Power brake assistance isn't necessary on such a small/light car. Hell, the front discs aren't even vented.

The lights are probably the largest single draw on the electrical system that I have right now.

[Varn]

Make sure you get your brakes back to 100%. The PO of my car saw fit to put oversized ventilated rotors on my vw.

I smile every time I slow down.

[Christ]

Originally Posted by Varn

Make sure you get your brakes back to 100%. The PO of my car saw fit to put oversized ventilated rotors on my vw.

I smile every time I slow down.

Check to make sure they didn't just put GTi discs and pads on the front.

They're a direct fit to the stock parts of your car, no mod necessary.

[oldbeaver]

I am after the same mod, to switch the alternator ON only when it is time for a smart charging. For me, this means not to charge when a big load to the engine is demanded.
For example, when the engine is idling.

Now, how to accomplish this objective? A switch may be used by hand, but the ideal is an automatic switch, controled by rpm, load or throttle position.

Have you made the mod? Please share that with us.

OldBeaver

[Piwoslaw]

If you want only deceleration charging, then rpm>1500 plus foot off throttle should be enough.

You could also have it charge when the engine is most efficient (~80% load).