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Higher Voltage: Fool Your Alternator?


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Thread starter #101
Hello again,

For my old Hyundai i bought a brand new battery and brand new alternator and i found that the alternator would not keep the battery charged correctly at 14v. It had to be a little higher than that. I had to bring the battery in the house now and then and change it with a 10 amp battery charger or 10 amp power supply and set the voltage much higher than 14v. I think it was 14.7v or something like that. That way it would hold the more normal voltage over a month or two when used in the car again and with short trips with the car.
Yeah with short trips the battery doesnt get as well charged either if the charge voltage is too low.


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My newer Chev Silverado 1/2T pickup is too smart for its own good. The Alternator Voltage Regulator is controlled by one of the many on-board computers. It shuts off the alternator during start. A few seconds after start, the VR is set to ~14.8V, but the exact voltage seems to be a function of engine compartment temperature. After about 10min of running, the voltage drops to about 13.8V, and it stays near there for the duration of the trip. During the trip, as the engine compartment gets hotter, the VR voltage is further reduced.

I'm sure that the algorithm is published somewhere....

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