Avoiding Ice Reset When Battery Removed

[spelunkerd]

Some auto dealers (not Lexus?) use a small 9v battery attached through the cigarette lighter to maintain minimal voltage when the accessory battery is disconnected. That 9v battery maintains a minimal charge, so the computer and radio etc don't completely lose voltage and revert to factory reset when the accessory battery is removed. Does anybody know if it is safe to use such a device in a hybrid Lexus? I have a 2008 400h.

[Jim Nazium]

Some auto dealers (not Lexus?) use a small 9v battery attached through the cigarette lighter to maintain minimal voltage when the accessory battery is disconnected. That 9v battery maintains a minimal charge, so the computer and radio etc don't completely lose voltage and revert to factory reset when the accessory battery is removed. Does anybody know if it is safe to use such a device in a hybrid Lexus? I have a 2008 400h.

That wouldn't work. The vehicle needs >12.5 volts in order to charge the lead acid battery. Typically it should be outputting anywhere from 13.5 to 16.0 volts, and with the right circuitry, can detect the battery resistance and vary it...

Otherwise, if it kept just enough voltage to retain memory settings (I believe <12 volts would do the trick) there would not be enough battery power to turn on all the electronics required to get the traction battery to take over.

Cheers,

MadloR

[cduluk]

The ICE reset takes like a minute... is it really that big of a deal?