> Andy et al, > > Some charge current notes: > > 1) Alternators naturally current limit at their rated current. Only if the 'internal' regulator is designed to do so. THis is not always the case, especially for the external regulators that don't know what the current is. > 2) If 13.8 volts is applied (room temp) to a good battery, the > battery limits itself to a safe charging current. Possibly for a starting battery that is not discharged completely. Try maintaining 13.8V while charging a completely discharged deep cycle battery, you'll be surprised at what the charge current is. I have test results for various batteries if you really want to know. > 3) VW does it wrong. The VW alternator regulator voltage senses > at the alternator terminal. The correct place to voltage > sense is at the battery, and many cars do. Please see #2. Agreed, this is necessary for 'properly' controlling charging. But the VW method works just fine for practical purposes. > > 4) The heavier the charging cable the better since the reduced > voltage drop reduces the error introduced by #3. .....resulting in increased charge current. Gotta be careful here because it is sometimes good to limit the charge current. Don't want to fill our vans full of hydrogen gas do we ??
I'm not sure if the VW alternators have a current linit in their regulators. If so does anyone know how it works? |
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