Prius Optima Aux Battery upgrade

Since the Prius is our gas-guzzling secondary car - it stays parked for weeks at a time. In a normal month is might be driven twice, and in some months it stays parked all four weeks. I have been concerned about the tiny Aux battery keeping up with the parasitic drain of staying parked. The original Aux battery has served me reasonably well, though when I have left ONE light on (my cargo LED replacement that only draws 1W) the car would not start the next morning. And MAN does the Prius get confused when it won't start! So for sanity, I figured I'd put an Optima Yellow Top in here and hope for the best. Purchased from e Learn Aid - they offer a nice installation kit ($15 extra) and reasonably good instructions (at least they're in English!). The price on the battery (Optima D51) is about the best you'll find. Fast and free shipping. The D51 was discontinued in 1996 due to some failures, and apparently some flaws were fixed, and the battery was put back on the market in October, 2007.

Hobbit performed this mod a few months after I did, and found several ways of improving on it. See Hobbit's page here.

Here is the regular view you get by just pulling up the floor cover on the passenger side of the cargo area. We've all seen this before. And every time I've looked in there before, it was about ALL I wanted to see. But not today!

Just about ready for removal.

Presto. Old battery gone. Sure is nice and clean when the battery is kept inside the vehicle!

Here is the original and the Optima side-by-side with the "kit" in front. The kit is four parts. A new ground strap, and new positive clamp, a vent plug and hose connector. Not a lot for your $15, but it is sure handy to have them all supplied in one place. Worth it for the heartache it can save.

The new Optima (and new ground strap) in place.

All hooked up and ready to go.

Besides the price and effort, the only downside here is losing your MPG reading and your radio stations.  :)

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