I was in Cabela's in Waco today looking for a small gel cell battery for the graph.
They have their 12 volt 8amp battery on sale for 19.99 (down from 39.99) they had several left.
The gentleman helping me find the batteries did not realize they were marked down that much.
Of course, I picked one up. You might check the Cabelas in your area.

They've been that price there since they had a sale on them last December. I don't know if they never changed the price back or if it's a permanent deal.

There is a great battery/ box combo at academy for $40. It's made by stealth cam that comes with 12v battery, charger, water resistant box and long power cable to be attached to the always so short power cables on fish finders. Hope this helps a few! I bought the cabelas battery and now it's on my return list:)

What part of the store did you find that combo in?

Never mind, found it with the other der feeder batteries.