Swap to AGM (and new charger?) or Stick with Flooded (HPDI)

[cldtx]

Hello - I purchased a 2007 Skeeter ZX225 w/ HPDI 225 and 112lb 36v Terrova. I will likely run two 9-10" graphs (Echomaps), nothing crazy. The boat runs well, and currently has four flooded batteries - Starting on a MK301D charger, and the three trolling on a MK345 (no D or PC designation, so I am guessing pre 2014?). I have pretty much been doing 2-3 hour fishing stents with recharging at my dock immediately after. All has been well, but the batteries are old, don't match, and I don't have a ton of faith in them once I start venturing out, so I am thinking about replacing them. I have an extra Blue-top 31 that I could swap in as the starting battery (or buy a Duracell 31 AGM), and I initially decided to go with 3 of the Sam's club flooded 31's. My only question there would be the AGM on the HPDI (and the MK301D), but it sounds like they charge ok. In any event, that led me to the question of AGM trolling batteries, which led to my understanding that the MK345 may not work for the AGMs.

So, the question(s) are:
(1) Does the old MK345 work on AGMs;
(2) If not, is it worth swapping to AGM trolling batteries, which would lead to about $270 extra for the batteries and another ~$350 for a 3 bank charger?;
(3) If I am not doing long days on a regular basis, would 3 27 AGMS (for less money than 31 AGMs) still outperform 3 flooded 31s (having a hard time getting RC off the sam's website)?; and
(4) Will the MK301D charger work with an AGM?

Thanks!

[krindgen]

Go to the MK site and see if that charger is AGM compatible. I think you're fine with the trolling batteries myself. Question is do you see yourself needing the big reserve capacity for the cranking battery for running pumps and if you add electronics in the future. I don't fish long days and bought an X2 which is overkill, but I feel good about it.

[RFSims]

#4. Yes. AGM and flooded cell use the same charger. A gel battery uses a different charger.

[Transom]

The big benefits to an AGM battery are ruggedness, less draw down, ability to mount at odd angles and leakproofness. Wet cells are just fine for most applications. I have an aluminum boat so I really appreciate that the AGM batteries are much more leak resistant than flooded cells. If I had a glass boat I would be much less likely to pay the premium for them.

[EL Skeeter]

https://deepcyclebatterystore.com/do...looded-vs-gel/

[PMantle]

https://deepcyclebatterystore.com/do...looded-vs-gel/

I'll be testing that theory soon. I'm mixing.

[cldtx]

Thanks. With regard to the MK website and manuals, that is one of the problems I am running into. I did not find the manual for the older (non-digital, non-PC version) charger. There is that, and the likelihood that the manufacturer could overstate its abilities. Sounds like opinions vary. I will likely go AGM for the starting and Flooded 31's for trolling, to be safe and economical. Thanks!