We had an Odyssey 925 battery just like a lot (most?) other -10 owners. It had been in service for two years so it was time to preemptively replace it. After much deliberation I decided to go with an EarthX ETX36 battery. They are relatively unproven in aircraft but not a complete wild card. Before investigating the topic very much I was eyeballing Shortai batteries and some other brands, which are indeed cheaper than EarthX, however they didnt have the integrated battery management system that I believe is important. Not to say I couldnt buy/make a BMS to stick on to those other brands, but I like what EarthX is doing and wanted to go that route.
On paper its easy to see that my old battery weighs 26lbs and the new one is under 4lbs but it wasnt until I actually lifted the old one out and laid it onto my work bench with a hefty thud that I realized what a big difference the new one is going to make in the plane. I stuck the new battery in the same location as the original, which is behind the baggage wall per plans. I pop riveted a piece of angle onto the floor of the battery box to hold the new battery in place and was able to use the existing bar across the top of the battery after I cut the bolts down to size and re-threaded them. I'll have to snap a picture next time I've got that area opened up. We've been flying with the new battery for a few months now and over all I am extremely satisfied with the performance and weight savings of this battery. It cost more but its supposed to last twice as long so in the end I feel like I just got 20lbs out of the aft end for free! Win!