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Time to replace both (2018) batteries in my 240. Going to get AGM type. One starter and one deep cycle. What brand/model is considered best for reliability and warranty? Please don't tell me "I installed a XYZ battery and it seems to work fine." Let me know what your research led you to buy. Seems there is MUCH more advertisement on the internet, YouTube, etc, vs legit research. Thanks in advance for useful info.

Odyssey. I have used them on boats, motorcycles and cars. I had one that finally gave up after close to 12 years that I used as a house battery on my pontoon boat. I switched temporarily to some Duracell AGMs but I will be going back to the odyssey after a 5 year Duracell just failed. 5 years isn't bad but I know Odyssey last longer.

Odyssey Extreme AGM dual purpose.

Another vote for Odyssey AGMs. Running a group 27 for starting and group 4D (>150Ah) house battery in a 1995 220, plenty of juice to run the stereo for hours on anchor. Also a shout out for ProMariner Elite 3 onboard chargers, if you don’t have one or need an upgrade.

Odyssey AGM is certainly a better battery, but I've been buying Interstate 27DC Marine/RV batteries from Costco simply because they're so much cheaper ($90). I have one that's 10 years old and one that's five years old right now, and I intend to replace the 10 year old one this year with a new one despite it still working fine. Note I usually use the newer battery as the starter battery and the older one as the house battery, so the odds of getting stranded by using "cheap" batteries is pretty low.

Regarding AGM batteries, the only one that I've seen tested as competitive with Odyssey is the X2Power (which I've never used, but you can check out the reviews), but it's similarly-priced. See: https://www.batteriesplus.com/productde ... li27agmdpm

jhnmdahl wrote: Tue Jul 08, 2025 4:44 pm Odyssey AGM is certainly a better battery, but I've been buying Interstate 27DC Marine/RV batteries from Costco simply because they're so much cheaper ($90). I have one that's 10 years old and one that's five years old right now, and I intend to replace the 10 year old one this year with a new one despite it still working fine. Note I usually use the newer battery as the starter battery and the older one as the house battery, so the odds of getting stranded by using "cheap" batteries is pretty low.

Regarding AGM batteries, the only one that I've seen tested as competitive with Odyssey is the X2Power (which I've never used, but you can check out the reviews), but it's similarly-priced. See: https://www.batteriesplus.com/productde ... li27agmdpm

The X2 battery exclusively at Batteries Plus is supposed to be a great battery, it is the exact same battery as the Odyssey just in a different proprietary wrapper but the same battery. I was looking at both and found i could actually get a better price through West Marine on the Odyssey by buying online and using some online coupon codes. Batteries Plus also had some coupon codes but the max total discount they would allow was $30.00 total, West Marines website allowed me to stack a couple codes and apply it to each battery (I was buying 3 group 27's) so the savings was a couple hundred $'s. They were still expensive but West Marine was the best deal i could find after adding the codes.

jwill323 wrote: Tue Jul 08, 2025 5:21 pm


The X2 battery exclusively at Batteries Plus is supposed to be a great battery, it is the exact same battery as the Odyssey just in a different proprietary wrapper but the same battery. I was looking at both and found i could actually get a better price through West Marine on the Odyssey by buying online and using some online coupon codes. Batteries Plus also had some coupon codes but the max total discount they would allow was $30.00 total, West Marines website allowed me to stack a couple codes and apply it to each battery (I was buying 3 group 27's) so the savings was a couple hundred $'s. They were still expensive but West Marine was the best deal i could find after adding the codes.

Good to know this. Way back when, Sears Diehard AGMs were also Odyssey and they were at least $100 or more cheaper.

jhnmdahl wrote: Tue Jul 08, 2025 4:44 pm Odyssey AGM is certainly a better battery, but I've been buying Interstate 27DC Marine/RV batteries from Costco simply because they're so much cheaper ($90). I have one that's 10 years old and one that's five years old right now, and I intend to replace the 10 year old one this year with a new one despite it still working fine. Note I usually use the newer battery as the starter battery and the older one as the house battery, so the odds of getting stranded by using "cheap" batteries is pretty low.

Regarding AGM batteries, the only one that I've seen tested as competitive with Odyssey is the X2Power (which I've never used, but you can check out the reviews), but it's similarly-priced. See: https://www.batteriesplus.com/productde ... li27agmdpm

It's crazy how everyone's experience is different. I guess it makes sense b/c interstate doesnt actually make batteries they are just a marketing company that sells batteries made by several other companies. Maybe luck of the draw is in play here. We had two interstate Group 24's die in our boat over the winter. My fault, I didnt pull them, never checked water levels, they were not on a charger, and it got super cold this winter. I assume at their state of charge they ended up getting close to or actually freezing. Mostly on me for not taking care of them I know, but they were less than a year old.

I switched to Duracell's from SAMS, which are rebranded Deka's. Personal preference but never had an issue /w an East Penn Battery. Cant speak to their AGM offerings, and maybe Odyssey is better there - but if you want to run traditional lead acid I Deka's at Sams at $95 per is a very attractive option.

A lot of Interstate batteries are East Penn now too, as are NAPA and WalMart EverStart supposedly. Exide as a company is gone, with Stryten having acquired their assets, and Clarios is the former Johnson Controls. It's a mess. Exide in particular keeps declaring bankruptcy to get out of issues in their past mishandling of lead.

Interstate is very popular where I live.
They came as original equipment and I replaced them both last season just to be safe.