Forum Discussion

MEXICOWANDERER's avatar
May 24, 2017

Big Box Warehouses And Deka AGM Batteries?

A friend with a tow truck (Ford 7.3 Diesel) wishes to purchase a pair of decent AGM batteries. This is for south-of-the border, on the Pacific coast side.

Lifeline is not the best choice for ultimate CCA. I fitted his 3G alternator with a fixed voltage 14.0 regulator. Normal service see's short runs or long runs in 108F summer temperatures. The truck has a float charger plug in.

He jump starts big rigs. Sometimes the engines are 570 horsepower 3406 caterpillar and they need all the honk they can get to turn over.

His budget is $429 dollars (peso to dollar conversion).

Rather than go on a wild-goose chase I thought I'd ask here, first.

2 Replies

  • FYI, for those who don't follow these things, both Deka brand and Duracell brand lead acid batteries are manufactured by East Penn Manufacturing.

    The original battery size for a 7.3L PowerStroke is Group 65. The Group 31 Deka/Duracell AGM batteries are considered "dual purpose" and only add about 50 CCA @ 0F.

    MEXICOWANDERER wrote:
    I fitted his 3G alternator with a fixed voltage 14.0 regulator. Normal service see's short runs or long runs in 108F summer temperatures.

    Above average charging voltage (most VR will settle down to 13.6V-13.8V) and high under hood temps are the WORST THING YOU CAN DO TO A BATTERY ! "Smart charging" systems were invented not only to save a 1/10th of a MPG but to limit overcharging which makes heat in the battery. Almost all newer cars now have the battery in an insulated sleeve to help limit heat from the engine.

    This a good reason to have a flooded cell battery, because he is going to need to add water A LOT !

    MEXICOWANDERER wrote:
    The truck has a float charger plug in.

    Why ?

About Technical Issues

Having RV issues? Connect with others who have been in your shoes.24,283 PostsLatest Activity: Jul 17, 2025