I have an 8-foot pond boat I'm fixing to put back into action. Do they make such a thing as a good, light-weight trolling motor battery?
My last battery weighed 80 pounds, and that's more that I like to lift.

Group 24's generally weigh about 50#'s. On a puddle jumper it should last all day. If only using for a few hours at a time then you might be able to get by with a U1 sized battery. 25#'s or so but only rated for 3-35 AH.

I would be hesitant to believe that a U1 battery would have enough capacity. Additionally, even if it managed to work, the battery would probably be drained to a low charge level, which would shorten service life considerably.

I like the idea of AGM (sealed) technology for use in applications where the battery will be moved often. I have not compared the weight of a conventional and AGM 24 series batteries.

Conventional and AGM's weight about the same. I only threw out the U1 as a possibility of just using in ponds for short periods of time.

I have an 8 foot Bass Baby and struggled with the same issue. I could get'r done but it was no fun
carrying that beast class 31 battery from the pick up and putting it in the Bass Baby, even using a small
dolly to get it there. On one trip I wrenched my back a bit wrestling with the battery so I decided to
do something about it.

What I did has made all the difference in setting up my boat on the water. I bought some
35 amp hour Might Max AGM batteries. They weigh 23 pounds each. I run them in parallel
with clip cables I made. If I'm not going to be covering a lot of water I just take two. If I am
I will take all three batteries. I can still cover quite a bit of water with just two. When I say
a lot of water I'm talking about running all over a 50 acre lake from one end to the other, etc.
Basically, running 2 of these in parallel is like running one class 24 battery in respect to
amp hour capacity. Running 3 of them is like running one class 31.

I have an inexpensive "smart charger" battery tender for each battery and leave it on 24/7
when not using them.

Amazon sells these batteries for $64 each shipped. Or you can buy them from Mighty Max for the
same price.