I have a 2008 Prius, pkg #5. It gets used about once every 2-3 weeks in the winter. Is there maintenance to the 12V battery that will help it to maintain a charge? I have a portable, re-chargeable 12 V battery pack, JNS Jump-n-start (400 cold-cranking amps). Can this be used to charge the Prius' 12 V battery?
I'm away a lot on business. I use VDC Electronics Battery Minder on all my equipment to keep the batteries properly charged BatteryMINDer® Plus 12 Volt 1.33 Amp Charger-Maintainer-Conditioner (Desulfator) :: All :: Battery Chargers by BatteryMINDers.com Unlike a trickle charger, this device will not overcharge and ruin a battery. Of course, if you don't have a garage to park in, it would be difficult to find a source of power to run the device Maybe a solar charger?
Turn off the smart key system (SKS). If you drive it at least 30 minutes every two weeks that should be sufficient to keep it charged, although the total life of the battery may be somewhat reduced. Judging from reports here it appears that about four years is typical life in a cold climate. If there are any after-market electronics installed that you can't disconnect and which may present additional loads it would be wise to put a battery tender on it. Your JNS will get you going if the battery dies, but I believe it won't keep the battery charged.
