Winter is near and I am looking for new batteries for my 2006, 6.0. My choice is with a Costco Kirkland 31 group, 875 CCA. But I found some group 65 batteries for commercial tractor, big trucks, and they have a 950 CCA with 190 minutes reserve.
THey are bigger batteries and I would think that they put out more juice for a longer time, especially in cold temp.

Other than size, what is the difference in the gourp 31 or group 65 batteries?
I found on another forum that the CCA does not make too much difference because the starter will only take so much CA. Example, if the starter is designed to be 600 CA, even if you have a 1000 CA, the battery will not push out more power than what the starter is requiring. Also, he says that the higher the CCA for the same size batteries will die faster.

 

You have them backwards. The Group 31 is the commercial truck 3/8" NC threaded terminal studs. The Group 65 are what Ford uses in almost all of their vehicles.

The group 31 batteries wont mount very well in your existing boxes, and you have to adapt your cables or cut them up and install 3/8" eye terminals on all the wires. Way too much of a pain and not worth the corrosion problems associated with tamping with the nicely sealed factory cables.

I think a better thing to do for the winter is to keep them charged and keep them warm when you use them. That means install a battery blanket or heater pad under the batteries to keep them warm on those cold days when you plug in your block heater. If the stock batteries can't crank the engine when the block heater isn't needed, then you have a problems somewhere. An oil pan heater works wonders in the winter for starting as well.

We do the whole heater kit up here on a lot of government vehicles and include the factory block heater, an oil pan heater, battery heaters, and battery trickle charger. Sometimes also an auto trans pan heater.

Keeping it warm will grant you better starting and better life from your batteries in the cold.

 

I agree 100%. Stick with the grp. 65's. May not push more cca's but the remainder is left in reserve for extended cranking.

 

the truck takes bxt 65-750's or bigger.

 

Replace both batteries at same time.

Look for maxmimum CCA for the proper class of battery - - 65's in this case.

My Ford dealer had a great sale 2 years ago with rebates and installed them for me at no extra cost... so take your best pricing you can find and then check with your dealer.

Check battery manufacture code dates and look for freshest/newest date.

Have alternator checked at same timem (most will do for free, but sure about Costco).

Enjoy.... sure makes winter driving & starting less stressfull.

 

OK, i will check on those numbers. The best batteries I found where 950 CCA and 190 minutes reserve but they might be 31 group or something else. They have the normal prung to connect, but they are bigger than the one at costco.
Where I go in winter does not have electricity and I leave the truck in a parking lot, to plug it in I need to run the generator for a couple of hours. It is a bit long, so the best batteries is most important.

 

Its not all about CCA. These come with durable 650-750 Motorcrafts which last really well. A higher CCA battery will not last as long because to get the higher amps they use a more porous lead which has more surface area. This lead wears out faster. I bought 875 CCA Interstates and wish now I had bought the 750 Motorcrafts for longevity.

 

I know everything varies but my stk. batteries lasted 37 months. One past the warranty period.

 

The batteries in both my and my dad's '03s lasted over 5 years. I retired mine because one was damaged in a collision and I replaced the pair. My dad's '03 is still running the stockers, but I think he'll replace them before this winter.

 

Mine are the original, they have 4 years now. They where good this summer, but last winter, they did not crank very long, they died pretty quick.

That is what I read on another forum, for the same size battery, higher CCA will not last as long. Plus, the starter will not pull much more CCA than what it is build, don't know

I would think that the higher CCA will be better like in the minus 20,

 

i just replaced my 03 750 cca batteries with a set of 850 cca motorcraft replacements even though my originals were still good.you can"t take a chance with the ficm running with low voltage.184,000 miles and running great.03 6.0 .

 

What is the problem with FICM and low voltage?

 

Low voltage equals higher current and the solder joints don't seem to like that.

 

The batteries on my 2005 F 350 diesel are exactly seven years old. These are the stock Ford 750 amp batteries.I will be replacing them this month. Probably with the Costco 65 batteries.

 

65-850? .