Wow, I’m actually going to publicly disagree with Ralph this time.
Back in 2017, FM was using Universal Power UB121xxx AGM batteries unless you had the expensive lithium upgrade.
Universal Power batteries are among the cheapest AGM batteries out there. They are deep cycle batteries which is the type you want for the house bank. FM was using a one size fits all philosophy in buying batteries.
The UP batteries were not a good choice for use as an engine or thruster battery though. Dozens of threads on this forum about MUCH, MUCH better starter type AGM batteries for use in those roles. You want lots (900+ CCA) of power for starting or the thruster. The Odyssey, X2Power and Optima AGM starting type batteries are frequently mentioned.
Our 2017 C-28 uses Group Size 31 batteries. I am not sure what group size are used in the RT-29.
On my C-28, I replaced the original six year old Universal Power AGM for both engine and thruster batteries the first month I owned the boat. Still have newer UP batteries the seller installed in the house bank though. The UP batteries are ok (but not great) in that role.
PS: Heard from both a 2019 R-29 and 2017 R-29 owner that you have Group 31 sized batteries in your 2017 R-29S. The battery cables should be labeled near where they connect to the battery terminals. If you go with a different brand starter battery (like one of those mentioned above) you may need battery terminal adapters but those are easy to find and inexpensive.
