Alternator output adjust v1

327

03:00:30

Circuit for dropping sense voltage to alternator regulator to increase output voltage.

Press momentary button to 'excite' alternator.

Simulating alternator sense with input to VCVS and output of alternator with output of VCVS.  Adjust potentiometer to adjust voltage drop across MOSFET.

Zener diode to limit max voltage.

This is a proof of concept only.

The idea behind this is due to most alternators in modern vehicles being controlled by the ECU and providing a low charging voltage to the lead acid battery which ultimately will shorten its life.

By increasing the charging voltage slightly we may enable the battery to be fully charged.

Further ideas would be to include current sensing on the alternator output allowing voltage to be lowered to a 'float' level when current falls below a preset threshold, or after a predetermined time as well as temperature compensation for extreme hot/cold environments.  Of course the would require some sort of MCU.

published 7 years ago

BillyT

7 years ago

Good idea, Ford had to upgrade their software because they cut the charging too much. The problem is because the engines are smaller, they virtually stopped charging the battery when the engine was under load (acceleration, climbing hills etc) so we were ending up with flat batteries.

damien0505

7 years ago

Hi Billy, Many thanks for the comment. Most manufacturers do the same these days. Pretty damn annoying when you have re reasonable sized turbo diesel engine that has more then enough power and torque. There is the quick (and dirty) hack of placing a diode inline with the alternator sense wire, but I am aiming for something with a little more intelligence, that can monitor voltage, current and temperature to ensure a more efficient full charge of the battery. While the concept works great in my head and that building blocks are all easily accessible, I just have to tie it all together with suitable microprocessor code to make it work the way I am planning!

BillyT

7 years ago

@damien, only problems might be if they stop the generation instead of reducing the generation.

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