What kind of Battery?

[akram]

Here is the thing with Optimas. Your yellow one is not good for starting especially on diesels. Also it is the old Optimas that are gel. Depending on exactly when the red tops were bought the could be gel but likely are AGM. Which is a very good thing. All the Optimas I've had blew up and were the old gel ones. Optima brand aside AGM is the way to go. Now optima may only go up around 800cca. But others start around there. Most are over 1000cca. The die hards are 950 and up.

I won't buy an optima out if principal. Just way too much bad luck. I will consider another brand of AGM battery though. These are holding up very well in diesels and the cold climate.