AGM batteries – Worth the Extra Cost

With a upcoming Canada Trip I thought it would be a good idea to replace my 2 Deep Cycle Batteries. They came with the boat when I purchased it used last year. The prior owner said they were 2-3 years then. With my trolling motor being a bit underpowered for the size of my boat and with possibly needing to use the trolling motor 10-12 a Day I figured I better just go ahead and replace them. The ones in there are Interstate and since I have a Interstate battery store close I thought I would just replace them with new group 27 interstate batteries. Once at the store I saw that they had the Group 27 AGM batteries on sales or right around 200.00. My question is are the AGM’s worth the extra 100.00 or so each? Do they possible add any additional Run time per charge? or possibly last twice as long? I’m a bit unsure what the advantages of AGM batteries are. Thanks for all of your reply’s in advance

Looking forward to hearing some longevity stories from AGM users. With lead batts last 5-6+ years when maintained properly its hard to justify the extra money for weight savings alone. Discharge time is a factor as well.

“AGM batteries – Worth the Extra Cost?”

No, not in my opinion.

If you want longer run time, put in bigger lead batteries. The only advantages I see are less weight and maintenance free. I add water once every couple months and charge my batteries every day year round. I usually get 6 good years. From my research an AGM will last no longer than a lead battery.

Joe Scegura wrote:

“AGM batteries – Worth the Extra Cost?”

No, not in my opinion.

If you want longer run time, put in bigger lead batteries. The only advantages I see are less weight and maintenance free. I add water once every couple months and charge my batteries every day year round. I usually get 6 good years. From my research an AGM will last no longer than a lead battery.

I thought about increasing to a Larger group size but I don’t think I could fit any larger battery in the storage area – At least not in the current battery trays. The onboard charge is also mounted in the same battery area. Ideally I’d like to upgrade the trolling motor to a 36 volt system but once again I don’t know how to make it fit – Even if I relocated the onboard charger.

Did a little googling and found this:

Sounds like faster charges and less likely to be damaged due to vibration when bouncing the boat around.

Edit: Trying to get the link right AGM battery advantage

Yes. Definitely worth the price. The biggest perk is they hold their charge. You can charge it in the fall, come spring it’s still 100% charged. I know mine has lasted quite a bit longer than my old lead batteries…that said, I never spent the money on lead then I now do on AGMS.

Also $50 off at cabelas now which puts them at a great price.

Make sure your charger will work with AGM batteries.

I have a friend that does maintenance work at the Int’l airport, and I asked him the same question about lead vs. ADM. He said in a high usage application, AGM all the way, not even an afterthought. In a recreational application, marginal use, then they likely do not have the value to match the cost. One trick about charging AGM batteries if you do not have an AGM specific charger, is hook the ADM battery to a lead battery, and the charger to the lead battery, it will charge both batteries.

This is always a great conversation.

If you are going to get a lot of use out of them, choose the battery with the highest reserve capacity or highest amp hours. The less you discharge a battery and recharge it back to 100% (cycle) the longer the battery will last. This is very important.

Here’s the stats on the Interstate Batteries.
https://www.interstatebatteries.com/recreation-vehicles/marine-batteries/deep-cycle
https://www.interstatebatteries.com/recreation-vehicles/marine-batteries/dual-purpose

AGMs do have a lot of pros vs LA batteries, but I don’t think they are always applicable.

AGM pros over LA
– much less discharge between cycles
– faster recovery from large amp draw
– much more durable
– faster charging
– can be mounted in any orientation(layed on their side)

If these pros are worth $100 to you, by all means get them.

I bought the group 29 LA batteries from Interstate because of their reserve capacity. I had to make room to make them fit but it was worth it. They aren’t much bigger than the 27s in physical size. Less than an inch in each direction.

4 BUCK wrote:

Make sure your charger will work with AGM batteries.

Most onboard and newer chargers have have the same charge setting for LA and AGM…typically you need a different charger or setting for Gel batteries.

fishthumper wrote:

With a upcoming Canada Trip I thought it would be a good idea to replace my 2 Deep Cycle Batteries. They came with the boat when I purchased it used last year. The prior owner said they were 2-3 years then. With my trolling motor being a bit underpowered for the size of my boat and with possibly needing to use the trolling motor 10-12 a Day I figured I better just go ahead and replace them. The ones in there are Interstate and since I have a Interstate battery store close I thought I would just replace them with new group 27 interstate batteries. Once at the store I saw that they had the Group 27 AGM batteries on sales or right around 200.00. My question is are the AGM’s worth the extra 100.00 or so each? Do they possible add any additional Run time per charge? or possibly last twice as long? I’m a bit unsure what the advantages of AGM batteries are. Thanks for all of your reply’s in advance

I have 3 AGM batteries. starting and 24volt trolling. I am going on 10 years with no issues. My 150 etec charges my trolling batteries once the starting battery is charged. I do a lot of long runs and I have never had to plug in my charger overnight when in Canada. Great batteries.

DTW

Could have bought either for my new boat-dealer said AGM is not worth the extra money.

Go to a 29 lead as mentioned previously, a better cost benefit, just cut my tray on one end.

If you don’t mind the maintenance issues like keeping the cells topped off, keeping terminals clean, charging during off season etc. then save the bucks. I hate doing those things plus always ended up with acid holes in my jeans. Am on my second set of AGMs and won’t go back.

If you fish smaller lakes, ie not Mille Lacs, Leech ect, that get nasty, then stick with regular batteries. My boat lives on Rainy and for me it pays off to have AGM batteries that can take more abuse.

AGM is the ticket in my opinion. No maintenance and longevity. I’m on the water a lot by myself and the last thing I want to worry about is batteries.

AGM all the way. Auto, boat, atv, sleds and motorcycle. No maintenance and store for months without needing charging.

AGM all in.! Winter i left them in my boat without worry,Spring still 100% charged.!

I’ve been running flooded cell lead acids for about 15 years and haven’t had too many complaints. They typically last me about 5 years. I don’t troll for long periods so I don’t tend to discharge them deeply. Plug in the boat every night. Add water every couple months.

As said above, Cabelas has their AGMs on sale right now and it’s tempting to grab them as I think it’s worth the extra $60/battery.

My charger says it can charge AGMs just fine. Same setting as flooded cells. Separate setting for gels, which I haven’t used.

Group 29 are usually only a 1 quarter inch longer than group 27 batteries. Never saw one that was taller or wider. They usually will fit in the same tray as a 27.

Went to AGM. Get’s rough on lake I fish, had a lead battery leak in my compartment. Got them on sale, love them so far.

mxskeeter wrote:

They usually will fit in the same tray as a 27.

A word of warning. Mine didn’t. Had to buy new trays.

FYI, you don’t need trays if you can secure the batteries from moving or bouncing.

biggill wrote:

FYI, you don’t need trays if you can secure the batteries from moving or bouncing.

Aren’t trays also to contain any possible seeping or spillage? I got lucky and my existing trays were already sized for the next larger batteries. Went to 29 lead myself. I get in very rough water and wouldn’t accept not having a solid tray under a battery.

Chuck Melcher wrote:

<div class=”d4p-bbt-quote-title”>biggill wrote:</div>
FYI, you don’t need trays if you can secure the batteries from moving or bouncing.

Aren’t trays also to contain any possible seeping or spillage? I got lucky and my existing trays were already sized for the next larger batteries. Went to 29 lead myself. I get in very rough water and wouldn’t accept not having a solid tray under a battery.

The statement “you don’t NEED trays” is in reference to being Coast Guard compliant. Trays are NOT required. The only requirement is that the battery be secured, it must not move more than an inch when subjected to a 90lb force in any direction.
Most battery trays also come with a means to secure the battery to the tray. This means of course that the tray itself must be secured as well.

Huntindave wrote:

The statement “you don’t NEED trays” is in reference to being Coast Guard compliant.

Neither the post I quoted nor mine said anything about coast guard compliant, or suggested anything relating to it. Strictly a mounting and secondary benefit of containing liquid direction