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What say the group regarding deep cycle batteries, specifically AGM?

I can read 50 different articles and get 50 different conclusions.

I've been researching batteries since this spring and planned to buy new batteries for this summer. I have a dual battery set-up. My house (deep cycle) battery is toast, but I was able to squeeze another summer out of the starter battery. So I will wait until next spring to replace. My batteries are the factory installed Deka Group 24 flooded--going on 6 years now.

As to your question about AGM batteries, my plan is go with AGM. They are more expensive, but they are an "install and forget" application as they require no maintenance, charge faster, and anecdotally they can last longer than flooded batteries. Cobalt located my batteries in an inaccessible place and the batteries are a PITA to service, i.e., check for gassing, water, connections. To do any kind of maintenance one has to remove the batteries, which are heavy and take time. With AGMs I should not have any more of this nonsense--and they will be on a DualPro charger year round to assure proper care and charging.

I've researched many brands and what I've discovered is that there are very few "stand alone" deep cycle AGM batteries. You'll find "starter" AGMs and "dual purpose" AGMs. My local battery guy, who specializes in aircraft and marine batteries, explained it to me this way. You NEVER want to use a starter for deep cycle applications, but any deep cycle battery can be used as a starter. The difference is that there is more lead in the deep cycle battery so it can handle both starting and steady current draws. The reason why starter batteries are offered is because they are less expensive, so it appeals to the consumer. So, if you can find only a "dual purpose" AGM battery, don't worry, it's really a deep cycle battery with a "it can start your motor too" label slapped on it.

Finally as far as brands, it's anybody's guess and preference. I've looked at Optima, Odyssey, Lifeline, and others. It seems that Odyssey is very popular.

Good luck, and please post what you find out or what brand of battery you ultimately decide upon.

Interesting take. I was looking at something for a solar bank for my boat lift. I keep coming back to AGM as the best compromise vs LiOn price.

I was looking at a brand called Wieze that seems to be affordable yet, perform well, then I saw a youtube videot that showed poor build quality. It's frustrating as everyone will be quick to judge a battery for being poor, but no one will step up and call one out for being the best. Heck, anymore all you can find is robotic voice videos that simply read the company's website content.

Part of me says go big with quality and sit tight for 8-10 years, and part of me say go cheap and replace every 3-4 years. Stuff like this drives me crazy.

Following. The Autocraft Deep Cycle flooded marine battery I bought just last spring is already kaput - or at least seems to be. Was reading up on Li-Ion cells this weekend trying to decide if its worth it.

slideruleracer wrote: Mon Aug 01, 2022 1:46 pm Following. The Autocraft Deep Cycle flooded marine battery I bought just last spring is already kaput - or at least seems to be. Was reading up on Li-Ion cells this weekend trying to decide if its worth it.

Which ones are you looking at? Most LiFePO4 chemistry ones don't have the current capability mainly because of the internal BMS.

Personally, I have had excellent luck with Odyssey AGMs and am currently using Deka AGMs through Sam's club.

I am in the process of making my own 280AH LiFePO4 batteries for my travel trailer. I have 120A BMS on each one of them but I could easily have 200A BMS on them.

bruceb58 wrote: Tue Aug 02, 2022 3:58 pm

slideruleracer wrote: Mon Aug 01, 2022 1:46 pm Following. The Autocraft Deep Cycle flooded marine battery I bought just last spring is already kaput - or at least seems to be. Was reading up on Li-Ion cells this weekend trying to decide if its worth it.

Which ones are you looking at? Most LiFePO4 chemistry ones don't have the current capability mainly because of the internal BMS.

Personally, I have had excellent luck with Odyssey AGMs and am currently using Deka AGMs through Sam's club.

I am in the process of making my own 280AH LiFePO4 batteries for my travel trailer. I have 120A BMS on each one of them but I could easily have 200A BMS on them.

I've just begun my search. Weize is one that has my curiosity, but I've seen mixed reviews. Really just starting my search. I have looked at Odessey and they are $$$$....almost LiOn pricey. I've kind of ruled out LifePO4 as I don't read a lot of good things about them in a solar application as it seems its hit or miss with charge controllers, but I'm a long way from knowledgeable. I don't have Sam's club, only Costco, and thy only have Interstate car starting batteries.

sailor55330 wrote: Tue Aug 02, 2022 5:18 pm I've kind of ruled out LifePO4 as I don't read a lot of good things about them in a solar application as it seems its hit or miss with charge controllers, but I'm a long way from knowledgeable.

I have LiFePO4 batteries(Battleborn) in my travel trailer and I wouldn't use any other type(chemistry) of battery. What kind of issues do you have with charge controllers? I use a Victron solar controller and they charge the LiFePO4 battery perfectly.

I use Odyssey in my motorcycles and will be buying one shortly for my F-150. I have one Odyssey battery that is the house battery on my pontoon boat and it is going strong for 9 years now although I am sure its capacity is pretty much half of what is was new and I don't need it to start the engine...just run lights and a depth finder.

This is one of the 280AH LiFePO4 batteries that I just made for my trailer. Making the second one now. I bought the cells from China and 3D printed all the parts other than the aluminum ends.

I was looking a boat lift solar system called lake lifter. I talked to them about using Li0n and they told me not too as they had issues with charging with their system. That’s really my only info. The system is based on a 24v motor so I would need 2 batteries, which adds up quickly on top of the system

sailor55330 wrote: Tue Aug 02, 2022 7:50 pm I was looking a boat lift solar system called lake lifter. I talked to them about using Li0n and they told me not too as they had issues with charging with their system. That’s really my only info. The system is based on a 24v motor so I would need 2 batteries, which adds up quickly on top of the system

Probably because the charging is built into their system and/or they don't understand LiFePO4 batteries which is very likely.

Bruce PM sent

Lithium is absolutely the future, just don't know how far in the future it will be to get the prices down, and trickle down the proper charging technology. That being said I had AGM batteries for years and actually had an Optima and a Cabelas brand both go bad within 2 years and needed replaced on our old boat (5+ years ago). With our Cobalt I put in new Interstate standard flooded batteries and have had zero issues for 3-4 years now. I keep them topped off with distilled water (RV charging system is great), and keep them on a trickle charger at all times year round in the garage. I will have a hard time buying anything else when needed when they are barely over $100 each to swap.

Yes lithium is the future... just once all the bugs are worked out. Guess what was the cause of this...
https://www.thedrive.com/news/44330/car ... e-atlantic

Trojan Deep Cycle are the best. You will pay more though

skno wrote: Sat Aug 06, 2022 8:18 am Trojan Deep Cycle are the best. You will pay more though

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We did enjoy our Trojans.

skno wrote: Sat Aug 06, 2022 8:18 am Trojan Deep Cycle are the best. You will pay more though

For a flooded lead acid true deep cycle, they are the best. However, not very good for a start battery especially with late model fuel injected engines.