Need a new secondary battery

I'm sure there have been many,many posts about batteries for winching and so forth but I've got a unique situation.
'Black Betty' has been running plural batteries ever since I got a winch mounted up five or so years ago. In so doing I pulled an older battery BCI 34/78 from 'BB's stable mate, 'Easy Bake' as being my primary driver I needed it daily for my commute (also dual batteries). The fit was off only by a little bit in the custom tray in the Jeep that I figured I'd address at a later time.
Now that that old 34/78 is starting to wane (not bad for a decade old battery) I'm looking to get a new one but I'm hoping to find a slightly shorter case that'll fit this custom batery tray better. Is there a BCI size no. that is shorter than 10.9" length and 7.8 width?

 

That's great! Thanks!

 

I'm leaning toward a 51R at Costco the price is right, still Johnson Controls that is the same I've had in my van for a decade. Still uncertain though.

 

I assume you have an isolater? When we replace batteries in the equipment we do em all a weak battery in the set will kill the rest. The alternator tries to charge the weak one and cooks the good ones.

 

Yep! I've been running a Stinger SGP (rather than SPG ~ Special Patrol Group ~Vivvians pet hamster of 'The Young Ones' british program

 

Tell me more about the stinger SGP THINGY, offer a link?

 

Hi Unkel Dale, This Stinger is kind of like an overgrown, dandified starter relay,by it's looks, but it does the job.
Here's the link; Stinger SGP32 200 amp Battery Isolator and Relay



It occurs that since I'm also running plural batteries in 'Easy Bake' that are both serviceable, I'm thinking I could sacrifice one of them to 'Black Betty' that is unless my logic is flawed.

 

Ok read the battery section, Thanks Howard
Read the Stinger, Thanks Turbogus

The battery I choose will depend on the inverter versus amps versus physical size of the pair of batteries/

Now how to run the electric circuit?
I have arranged for a 3b battery holder from a member to weld to the frame and will now use the OEM Battery holder on the fire wall body of the cj5 too for the second battery location, my PLAN is for an INVERTER system and a very small winch for brush removal, NOT to move the Jeep.

 

Just read your tag lines Unkel Dale I remember when our liberty plane from NAS Whidbey was a C118