catalina 309 original batteries

[sailingdeac]

Am looking to buy a 309. As best i can tell the catalina 309 came with two 4D batteries. I have never heard of that as opposed to group 31s 4d is 100 lbs!! They appear very weak, and i cant figure why catalina originally used 4Ds

 

[dlochner]

Catalina has an interest in a chiropractic practice?

My guess is the 4D's while heavy and difficult to install were quicker and easier to install than the equivalent 4 GC batteries. 4Ds have a larger capacity than Grp 27 or 31s. Add replacing batteries along with replacing the charger to your refit list.