Hello experts,
I need to replace my two 8D batteries in my 1976 MCI 5B.
They are 7 years old and have ben causing me issues.
Should I get AGM or stay with the standard?
Where can I get them?
I at a campground in Maine.
Thanks
Rick
You can go to 4 group 31 could be cheaper but you have to do cable work,the 8D's can be had at Auto Zone,O'rileys,Napa just about every place that sell batteries will have,the last 2 I bought from Bulbs Plus,Inter state will have those I would not go the AGM route for starting batteries most owner are going with group 31 truck dealers always have the 31's on sale
We buy our 8D batteries from Sam's Club with substantial savings. 7 year life for an 8D is good IMO.
Quote from: dtcerrato on June 05, 2026, 08:50:49 AMWe buy our 8D batteries from Sam's Club with substantial savings. 7 year life for an 8D is good IMO.
The sealed 8-D like Cat uses and the ones like Interstate sells the 8D-XHD with the thicker plates seem to last around 7 to 8 years, I never got more than 3 years from the Duracell Sam's sells, and they don't have much of a warranty either,I think it is only 6 months now
Quote from: luvrbus on June 05, 2026, 12:39:52 PMThe sealed 8-D like Cat uses and the ones like Interstate sells the 8D-XHD with the thicker plates seem to last around 7 to 8 years, I never got more than 3 years from the Duracell Sam's sells, and they don't have much of a warranty either,I think it is only 6 months now
Does the 8D-XHD have any kind of warranty?
When I got my last set of battery's from Interstate All Battery Center. That the warranty didn't really apply.
So hey a secondary duty for my solar is maintaining the battery charge. I am in the process of redoing the heart of my solar system and have managed to flat line both the 24V and 12V systems in the process as I get my new configuration into play.
The Interstate 8D-XHD have a 18 month warranty not bad for the 8D
When I looked up the Interstate 8D XHD it stated it had a 6 month warranty.
It seem all warrantys are getting shorter.
That doesn't look like the sealed 8D-XDS,it has the specs of the MDS 8-D the XDS has 1400 CCA and 1750 CA and weighs more, I did notice in the new Interstate catalogue the warranty for 8D-XDS is 15 months now,something is screwed up I will ask my Interstate guy Monday
The last set of 8Ds we went through in four years were NAPA commercial. We think we prematurely killed them by keeping a 3 stage converter on them. We replaced them with the Sam's Club brand because we've gotten four years out of them in the past for a lot less money. We have five group 31s in the house bank we purchased the same time as the Napa 8D that are the same level commercial and they're still going strong but receiving more TLC hooked to a Magnum 4 stage inverter/charger. A lot has to to with how well they're maintained, right?
It's not an 8D but I priced a battery for a friend that his Chevy Duramax pickup has the stop and start feature they use an Enhanced Flooded Battery (EFB) the price is crazy for those, I am staying with the older stuff
I'm going to buy two from local Rural King. About $214 each and 2 year warranty. We'll see how they do. At my age, they don't have to last 8 years.
Quote from: luvrbus on June 07, 2026, 01:18:25 PMIt's not an 8D but I priced a battery for a friend that his Chevy Duramax pickup has the stop and start feature they use an Enhanced Flooded Battery (EFB) the price is crazy for those, I am staying with the older stuff
The problem with the Start/Stop feature is that the vehicle has a BMS that must be reset when you change the battery, depending on vehicle something only the dealer can do. Even though you change the battery it soon marks the replacement as also bad.
switch to group 31 for start batteries. The first set went about 7 years and I just replaced then with two on sale at NAPA at $99 each. I did change the starter to 39MT geared but that was a few years after installing the 31s.