Lot of Talk about Batteries.......

[w30bob]

Hi Guys,

Seems there's been a bit of talk about batteries in a few posts lately.........so I have a question. What size Optimas (or other AGM battery) are you guys using in the M37 battery box? I dug around with the search function and found out the stock lead acid batteries are a size 2NH, which converts to a 22NF for civilian batteries. Optima doesn't make a red or yellow top in that size........and I couldn't find a size chart on the Optima site, just an application page. So which of their batteries fits our battery box?

thanks,
bob

[RMS]

here are my red 75/35s wedged in the battery box with the aid of some wood and rubber blocks.

[w30bob]

Hi RMS,

That looks like a good fit! Are they sitting on the battery tray or just the bottom of the box?

thanks,
bob

[Sal]

I have 2 Yellow top Optima batteries in my truck , the size is D51. They fit pretty good in the battery tray and the stock hold down without having to modify anything. There only 450 CCA , but my trucks not a daily driver and I haven't had any problems with them in 4 years.

[tbone1004]

The D51/D51R is the civilian equivalent of 2hn. The R denotes the terminals being reversed from normal positions which match the original 2hn's.
The 22nf's are a bit wider and may not fit in all applications but the D51R is a bit narrower than the 2hn. Optima only has the D51R in the yellowtop not the red. If your truck is 12v you can certainly get away with a single battery because the 2hn only has 450CCA's. I don't see the 37/75's in their redtop catalogue right now. Group 35's will fit in the box but I don't have a tray and don't know the dimensions of that. I have two group 24F's in mine right now and the Group 35 is the same size

[RMS]

i must have been suffering from dyslexia i wrote 37/75 it should be 75/35.

the battery tray is still in the box with rotted bolt heads keeping me from an easy extraction of said tray.

[rcamacho]

Old thread but helpful, I'm considering dual yellowtop as well

[RMS]

after 12 or so years one of my red tops has finally started to die. I will replace and continue to use optimas on all my rigs

[ZGjethro]

I run a optima red top in my 4runner daily driver, and I use a yellow top in my pop up camper. They have been great batteries. However, these are $200 plus batteries, any we need two of them. Has anyone run something like this http://www.apexbattery.com/trojan-24-ag ... aQodjqwHzA It is a 24volt AGM battery with 945 CCA and it costs about $125. This was one of the first google search results for "24v AGM battery".That is a far cry from the cost of two Optimas at $400-$500, depending on what style you buy

I realize that was a solar battery. Just floating the idea about single batteries, which could be cheaper than dual 12v batteries. For the first two years that I had my truck, I ran the 12v fuel pump off a center tap on the batteries, and it kind of messed them up. The fire dept I bought the truck from had wired it that way. That was almost seven years ago, and I will be looking for a replacement battery soon. How about marine or aircraft batteries?

Edit; Nix the idea of aircraft batteries. They are quite expensive

[isaac_alaska]

the spec sheet calls that a 12V battery, i'm not sure what the 24 means. but down below it says "volts.....12V"

aircraft batteries CAN be cheap to the point of being free, if you happen to be friends with a small aircraft mechanic. FAA says they have to replace them after x hours, whether they are good or not. (they're nearly always good, aircraft don't fly with sketchy batteries.) However, I imagine dual 12V batteries is probably the easiest option.

[ZGjethro]

Darn, it did say 12v. I missed that, and it popped up in the 24v google search. Must have been the group 24 part. How about something like this for $99?
http://www.walmart.com/ip/EverStart-Max ... y/20531538

[isaac_alaska]

Again, that's a 12V battery, it doesn't explicitly say 12V or 24V, but one review says they used it in their travel trailer, which would be a 12V application. Unless it says "aircraft" you can be almost positive (haha, battery pun) it's a 12V battery. You'd have to look up the dimensions of a "group 24DC" battery and see how they compare to what is stock, if you want it to fit in the stock battery tray with the stock hold-down.

I actually just replaced one of those batteries due to freezing it (-10F with it totally dead for a month.) Took it to walmart after i had thawed it out and charged it (so they wouldn't tell me the warranty was void by freezing) and they almost wouldn't exchange it because it tested good on their meter. I'm sure it would have worked but i wanted a new one so i haggled with them for a bit till they gave in. Not real relevant, except that i can say from experience the everstart maxx can handle being frozen at least once and still start a vehicle after it's thawed out and recharged.

[ZGjethro]

I give up. Saw the 24 dc and thought voltage. You get the idea though. Are there any simple 24volt batteries we could use without running two 12v batteries in series? and not spend $200-400 plus to do so? My truck is pretty basic and I have no aftermarket ad-ons to suck a lot of power. The battery starts the truck and runs the lights/fuel pump

[isaac_alaska]

You'll be hard pressed to find a 24Volt battery cheaper than $200 that will be as good as using a pair of 12V walmart batteries in series. Plus, the walmart battery comes with a free 3year replacement, so just make sure if it seems suspect or maybe it's froze once or twice, take it in and get it replaced before the warranty is up. The only off-the-shelf 24Vdc batteries i know of are meant for things like electric barbie jeeps (kids toys), and wouldn't supply enough current to reliably start the high-torque engines used in these trucks.

[ZGjethro]

Thats where I'm at now. When I bought the old truck, I ran down to the local auto store and bought two $100 dollar batteries, and they have worked for years. I will probably do the same again.