Odyssey still sells on 80% DOD but they readily admit that at 80% DOD you only get 400 cycles (in the lab). all recommend a 50% DOD not 80% DOD for optimal cycling life.

Today nearly every maker of AGM batteries, (except for Firefly) Lifeline, Deka/East Penn (and all their private labels), Trojan, Rolls etc. These far fetched marketing attempts really bit the AGM makers in the ARSE because cycle life at 80% DOD really sucked and still does for most AGM products, the only exception being the Firefly. Those far fetched promises of longer cycle life and more usable capacity than deep cycle flooded batteries was soon ousted as a mistruth in the 'real world' of PSOC use where battery cycle life really matters. That statement was exactly how AGM batteries marketed and launched themselves into the marine market. This is what is so frustrating about the internet, that poor information, is trumpeted as truth when it is simply not.

While most wet batteries are supposed to only go to about 50% depth of discharge, the AGM's are able to go to about 20% depth of discharge without harming them PROVIDED that you don't overcharge them at too high a voltage on their return. This is exactly how AGM's were originally marketed to US boat buyers in order to justify the cost difference:ĪGM Pro's: better cycling and depth of dischager over the wet or gell batteries. Keep in mind that AGM batteries cost more, tax alternators and belts harder, need to get back to 100% SOC as often as is humanly possible, and generally have a shorter cycle life (in the real world) than deep cycle flooded batteries or GEL batteries. Keep in mind that Deka rates their own AGM at HALF the cycle life of their own GEL's.įor a starting AGM the Deka is not bad but for cycling I would go with Lifeline or Odyssey. Conditioning or equalizing charges can greatly extend the life of Lifeline AGM batteries beyond the competition.ĭeka makes great GEL batteries that will outlast even the best of the AGM's. Lifelines can be equalized Deka and Odyssey can not. We like the maintenance-free and low wintertime self-discharge aspects of AGM, and they can accept faster charge if your charging capacity is higher, but they’re certainly not best in all cases.Lifeline & Odyssey are the two 'premium' AGM's. Quality flooded lead acid can definitely be found for lower cost, and they can be more tolerant of some types of use, like sitting partially charged for longer than AGM. You should also look at whether replacement with more AGM’s is really the right option for you. Ours spend lots of time on shore power, with a couple day-sails per week and a few nights on anchor per season, so a pretty sheltered life for AGM. Deka AGM’s are not very well regarded, certainly not as well as Lifeline, so YMMV. The Deka’s are $340 per Group 31, and the lowest cost Lifeline I could find was about $460. We figure 8 years is good enough for our use, so we’re replacing with the same model. (One went flat dead in the last few weeks, the other is still doing quite well, but we’ll replace both.). We had two Deka Intimidator Group 31 AGM’s that lasted 8 years. Lifeline is a premium brand known for very good quality AGM’s.

Lifeline 4d battery