Hybridization of a big standard diesel car

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Senior Member

Joined: 10/02/2015
Location: United Kingdom
Posts: 176
Posted: 06:12pm 04 Oct 2022      

Hello all, I currently drive a diesel car and whilst i would like an EV or even a hybrid, the prices are too high at the moment. I try to drive as economically as possible,  but as i live in a very hilly area there's often no option but to use the brakes downhill and use the trottle on the uphill.

So i was considering slightly hybridizing my existing car.

As it's my everyday work vehicle i can't do very much, but thought that if i could turn off the alternator when going uphill then turn it on again when going down, it would save some fuel by transferring the electrical load to when I'm engine braking anyway, and is a relatively easy mod.

Looking on the internet i get estimates of 2 - 4% fuel use on powering ancillaries, and as my car (vauxhall/opel astra) has electrically powered steering it nay be on the higher end of the estimates.

I was just wondering if anyone had tried anything like this? Or if folks thought it would not make a noticeable difference? Or had an opinion on whether the 2-4% fuel use was at all accurate?

I have two ideas of how to actually achieve this mod:
1) literally break into the wire between the voltage reg and the alt brushes. Possibly use an AGM starter battery to cope with the cyclic operation.
2) have a small liion battery and a buck converter to push the battery volts to just above the alternator setpoint,  and another boost convertor to charge the liion battery on the downhills.

In the initial phase i was going to try manual operation by the driver, but would be better to automate eventually either using the brake light swt or even reading the canbus to determine throttle position and engine revs.

Edited to say that should be 'bog standard' in the title - I've turned the damn autocorrect off on this thing but I'd swear it sneaks a few words in anyway!
Edited 2022-10-05 04:20 by mab1