I have a 2002 Buick LeSabre that needs a new battery and I have had some problem locating one at a reasonable price. The current battery is a Group 79 and it is not readily available from Costco and Walmart which are the lowest retain prices in this area of Georgia. Nobody locally has them in stock from either place. I have placed an order through Costco that may take three weeks or more to come in. Costco sells the Interstate brand while Walmart sells the EverStart Maxx brand. Both places list the Group 78 as an alternate. The group 79 specs state 860 CCA and the Group 78 states 800 CCA.

The Group 79 length is 12 1/16” and the Group 78 length is 10 ¼” long. My vent tubing is too long for the group 78 battery even though it will work electrically.

The reality is that there are not that many GM vehicles still on the road that still uses the side mount connection for the battery. My 2011 DTS uses a top mount for the Group 94R or H7 AGM battery for this car. Most auto supply outlets show the Group 78 battery as the replacement for this LeSabre vehicle.

I am considering changing the connections on the existing cables in the LeSabre to a top mount replacement. By changing to a top mount battery it will become easier now and into the future to find replacement batteries without having to order them in advance. The Group 94R has the positive connection on the right while the LeSabre has the positive connection on the left. The price for the group 78 battery is from $120 to $150 at Costco and Walmart, Auto parts stores are about $210 to $250 so there is a distinct price range for these batteries and the group 79 prices are similar.

I will have to determine whether there will be enough existing cable to work to make this modification. If not, then I plan to change the cable so that it will work with a top connection to the battery in the LeSabre.

I am curious whether there has been anyone may have already made this modification.

If so, I would appreciate some feedback.

Personally, I would stick with the factory connections, but if they are becoming more scarce then yeah it'* probably a good idea to change configurations. If you do, you need to be sure to change to a unit designed for a tube vent like your current one. I know the Outlook/Acadia/Enclave/Traverse have used the H6 for eleven model years (2007-2017).

Group Length x Width x Height
Group 48 (H6) 11 x 6 7/8 x 7 1/2
Group 94R (H7) 12 7/16 x 6 7/8 x 7 1/2
Group 78 10 1/4 x 7 1/16 x 7 5/16
Group 79 12 1/16 x 7 1/16 x 7 3/8

So . . . an H6 would be readily available for a long time. They changed to the H7 for the next generation Traverse/Enclave/etc. but it might be too long for your battery location. If you change to an H6, you'll have to make up for a 3/16" difference with the mounting block. The block might have enough wiggle room for this, but if not, find a few inches of heater hose, cut it length-wise, and put it around the end of the mounting block.

Most important: Make sure that the top posts don't get near any metal.