If you read the title, you may say “no kidding” to yourself, but sometimes we lose sight that there can be more than one way to approach a problem.

For instance, I have a car with a dead battery, and no matter how I tried to mend it with distilled water, trickle charging, discarge, etc- it just wasn’t coming back. I could trickle it up to 13v, but it was down to maybe 10v and ~85A the next day.

We all know that car batteries are expensive- most of them start at at least 3 digits ($100). I stopped by the well known auto shops nearby, and they were $120 to $160 with the core! I went searching for refurbished batteries, but nobody had Group 34 batteries available- it’s still winter and everyone else has a dead battery, too.

I stopped by Wal-Mart to get 4 quarts of Rotella 15-40W for $10 (great price), and saw that all of their Group 34 batteries were out (the cheapest of which was still $104.99), but they had Group 78.

Wal-Mart has a new “Value Power” brand made by Johnson Controls (They’re that company that makes the incredibly expensive “Optima” series). I checked the specifications on the “Value Power” 78- 600CCA, 750 above freezing. The Interstate battery I am looking to replace is 700CCA, and 800 above freezing, accordingly. Their duty cycles are nearly the same.

If you cross reference The BCI group sizes, we’ll find that they’re roughly the same dimensions- and more importantly, the posts are the same (positive is on the left when facing forward):

34 	10.30 6.80 7.90  L/H-POS
78 	10.30 7.10 7.30  L/H-POS

The dimensions, as we saw above are fairly compatible, and it even has the same little retainer “lip” for holding the battery in place.

I had already mentally measured the length of the cable under the hood when I pulled the battery (and how they mounted), which prompted me to then grab that $49.88 Group 78 battery with a pack of $2.79 “side mount charging post adapters”. The total cost? $57.27.

I was not only able to find what I needed, but I saved nearly half the expense by approaching my problem from a different direction by looking at the other resources I had available (car runs perfectly, by the way).