Since I usually fish from a kayak, battery weight is very important to me.  Not so much for the added weight in the kayak, but as I need to lug the battery to and from the kayak each trip.  I always carry two batteries in the car just in case something happens with one.  Recently the Interstate battery I have used for over 5 years stopped holding a charge (of course I found that out one a recent trip so the second battery saved the trip).  I was looking on-line for a good and inexpensive battery and probably going to get another deep-cycle from Wal-Mart.  I found an internet site (batterymart.com) and they had a deep-cycle, 12V, battery on sale for $77 (about the price as I was going to pay for a battery at Wal-mart).  However, this battery weighs about 25# versus over 50# for my current battery.  I was skeptical if it was really a true "deep-cycle" battery, but there were over 14 pages of excellent reviews with several indicating they used the battery with a trolling motor.  I used the battery for the first time yesterday at Blackjack Ranch and it maintained a good charge (I have two small solar panels I use when I fish) and after fishing from 8-4 the battery voltage stilled was 12.2 V.  When I got home, the battery was fully recharged in about 2 hours.  I am very happy with this new battery.  Here are the specs if you are interested:

Item # SLA-12V35

12 V 35 Amp hour sealed lead acid

Bill Fetech

Bill,

This is huge!!  My fishing time stopped last year because I injured my arm in the bicep/elbow area from lifting a battery. Dr. says it is not a tear but just inflamation but it has been sore all year. I had purchased the larger deep cycle battery from WalMart and I thought it was a great idea due to the size of some of the properties lakes and not wanting to have a battery die during the day. The battery weighs over 60 pounds.  I'm going to look into this idea that you have and hopefully it works out for you.  If I'm going to keep fishing PW I'm going to need to make a change like this. I did just renew so that means I am (right)?  I may contact you again before I get one just to see if it continues to work for you.   Thanks for putting this info out there.

Kirk. Welcome to the club. I fished with that battery again for about 5 hours, constantly circling Tarpley and the voltage did not get below 12.3 volts. Charging took just a couple of hours on a slow charge. If you want to talk, I can be reached at 830-535-4763.

Bill

Nice info on that battery, looks like i might be able to give up my two wheel dolly, with my heavy battery

I think it is a game changer especially for small trolling motors when used with the small solar panels. 

Bill

Hey gang,

Also keep your eyes open for the new lithium deep cycle batteries.  They weigh significantly less than a lead acid or gel battery and if I was having to lug a battery fairly often, I think I'd give them a look.  They are more expensive but supposedly last quite a bit longer than a lead acid.

Last week I fished Gallant Elms all day and there was a very strong wind. The battery never went below 12.2 V. Recharge took about 2 hours 

Bill

I got a lithium battery, despite the cost, a few years ago.  It was cheaper than the medical bills & six months of severe pain I experienced after twisting the wrong way while handling a 50# lead-acid battery.

Weight is about 15#, I think.  But the tech has improved since then, maybe the price is more reasonable now.

James,

Where do buy lithium batteries?

Bill:

How are these batteries holding up for you? I just bought two based on your rec.

Jason

It is still my primary battery and holding charge just as well. I even now have a Garmin 7" color display fish finder. 

When this battery does die, I will definitely buy another one. 

Bill 

Does the battery come with the nuts and bolts? Are the nuts and bolts compatible with the poles?  Worry about corrosion.

I'll get a photo when I get home today 

Bill,

Is this one you are referring to. http://www.batterymart.com/p-12v-35ah-sealed-lead-acid-battery-group-u1.html

Steve. That is it.  I was just going to post that link. 

Bill

I bought this one http://www.batterymart.com/p-12v-35ah-sealed-lead-acid-battery-insert-terminal.html then went to Home Depot, bought some bolts and wing nuts and saved $30 bucks.Same battery just different connections.

.

Just got this discount code from Batterymart 6OR12OFF  if anybody is in the market for batteries or chargers and wants to save some $

Jason. I paid about $70 for mine several years ago with free shipping. 

Bill