Could By-passing a Smart alt be this easy?
- Thread starter Colin Hughes
- Start date
DaveInDenver
Middle Income Semi-Redneck
Summation: He disconnects the battery current sensor. He calls it a shunt but they are usually Hall Effect. No matter, probably will trigger a trouble code and error condition.
Without the sensor he's assuming the alternator will still remain in regulation by itself at some default value. What actually happens depends on the vehicle, could be a whole lot of things. Some are stand-alone so the alternator will loose regulation, some might assume there's zero current so would fall back to their lowest value or might assume a worst case and go to their high duty cycle to prevent a flat battery. Some assume with this disconnected that you are supposed to be in storage mode (e.g. sitting on a lot) and will shut down as much as possible to minimize parasitic current drain and may not run. Can't say what all the possibilities are.
Not to mention you also usually lose the battery temp sensor and wouldn't be taking advantage of a smart charger's ability to prolong the life of the starting battery as intended.
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DaveInDenver
Middle Income Semi-Redneck
Everything depends on how your particular vehicle works. Most of them see current bidirectionally so connecting a load to the battery should might likely be recognized as though the battery is just consuming power while charging.
It may see a very large load going backwards (which can't isn't the starter or headlights) as a potential fault, e.g. the cable has fallen off or the battery has failed.
They allow for jump starting but that could be a single event exception, which might be what charging an aux battery would look like upon first start. What happens if it remains too long or across multiple starts could be different.