MG 29 V3- your thoughts please on my battery issue

I'll try and be succinct here; any thoughts or ideas wil be greatly appreciated. I've been through the forums, talked to the Lhs and basically am asking for anyone's help/opinion on why my batteries are puffing. Possibly just flat out quality of battery? Here's my setup as it sits now.

Proboat MG29 V3
Leopard 4082 1800kv
Seaking 180 amp esc
Castle creations 6mm plugs
Cooling system is upgraded plenty.
Flex .187
442/3, x642, x445, x447, GR 4057/3- ran them all.
Reinforced hull/hatch, blue printed, blah blah.

I've gone through:
2 sets of electron pro 5200mah 50c- one puffed up and read 155 degrees Fahrenheit. The exact battery on the other side was reading 104 degrees.

Same with the set of SPC 5600mah 60c. One is fine on temps and no puffing. The other was 150+ external temp and just now was worried it would pop when I pulled it out of the boat. I do not believe this to be a connection problem. All plugs, motor, esc have not gone above 115f. Just one battery in each of my sets and have been on both sides of the wiring harness.

This is my very first Rc boat. Never had one until November When i bought this one and basically upgraded as ive learned along the way. I learn quickly and know how to fiddle fart in the shop. Maybe I'm missing something here. Please help guide me as to how I may keep her fast and not buy batts every 5-6 runs boating.

Thank you Sirs,

How long are you running the boat? Are you running it until the lvc kicks in?Also are you running 6s or 4s?have you checked for any problems with driveline ? Are all the upgrades you installed new? Motor esc? Have you installed a extra set of caps on esc? I have same hull and have a mystic 29 will similar upgrades and never have that type of problems make sure you don't have any binding in you driveline also check bearings in motor these types of issues will cause excessive amp draw to your system. When you say one battery is puffed does it go down at all once it cools? Will try to help as much as I can but need more info to help pin problem down there are plenty of guys on here with more knowledge just have to ask.

Your probably running it for too long and draining the batts too much. I don't drain mine below 3.7 but mostly 3.85 and I'm done.

Sounds like you are running too long

Did you charge both batteries at the same time or just one at a time ?
Sounds like one had a lower charge and was the weakest link and got hot first when nearing empty

If you are using batteries in pairs they should be charged in pairs