31M Battery Replacement

So I had a Diehard 31M AGM battery...those were discontinued...all the other 31M AGM batteries I've found don't have the posts in the right spot...

Looking at the battery with the posts closer to me, negative is on left and positive is on right...all the other 31M batteries I've found are reversed...anyone have recommendations?

 

No info on your truck - year/model/engine size - assuming Tacoma

 

If stuck, the 24F AGM fits Tacoma as in my 2009 but only 710CCA compared to your 31M beast in the 900CCA range.

 

Lots of people used to speculate that the Odyssey batteries were rebranded Diehards, they might have the same post layout. Very expensive though.

 

X2 power/northstar should work. Heres my 31M northstar in the stock location. Had to make a differrent battery tie down though and the stock positive lead just barely reached

 

I had to make my own wires for this very reason. Not that difficult though. But I can see why someone would wanna keep things OEM as much as possible. I have the v6 though.

 

I had the same issue with a Pelfrey tray. Positive was stretched to the max; made me uncomfortable. Relocated to behind rear seat.

 

I took one of the plastic pieces off that hold the harness onto the fender and that got me a little more slack. Only one wire that is really stretched that i dont like coming out of the fuse box. Ill probably end up making that one longer just to be safe. Have any pics of your relocate?

 

I was motivated by a better weight bias, countering the Taco lean, and the fact that the Group 31M was succeeding at ripping the front of my truck off. The radiator core support and inner fender are shredded.

Ran both positive and negative because of reported grounding issues I read of. Used 4/0 welding cable to account for long run and amp draw from winch. Sheathed the cable in DuraFlex and added a little red shrink to the hot for easy ID later on. The White fitting is a boat hull pass through. I opened up an existing hole in the floor.

There are lots of convenient 6mm bolts that follow along the brake and fuel line looms. I used rivnuts where needed otherwise.

I built my own cage because all the existing ones clamp together in the front. The 31M fits with not much room to spare, so the top strap had to secure from the side. There are a ton of awesome Optima specific battery trays out there for the go fast guys.

I used a bunch of Swag Offroad fab tools I’ve been amassing over past projects.

 

Nice job, good looking install!

 

Northstar/X2 Power 27F FTW.

 

2006 Tacoma V6 TRD Off Road

 

Does the 24F come with dual post like the 31M?

 

If you are asking is a 24F setup like a marine battery? - no

1 pos. post - 1 neg. post like most automotive batteries

V6 4.0L come with a 24F or 27F if tow pkg.

Unless you have some unusual cabling - 24F should work.

 

My winch power cables are connected to the marine posts.

 

Unless this is a real game changer for you, the regular Odyssey battery I run has the winch cables right at the main terminal post or close on a couple of different rigs. I've been happy with the PC1500 battery and this one fit like a glove in my '06 Access Cab V6 TRD OR with towing package. Seems it would likely work for you too.

As for the prior comment about Odyssey being re-branded Diehards, the poster has it backward at best. EnerSys is a huge stored power company.

 

24F is a pretty weak battery.
Go w/a 27F.











(is there an echo in here?)

 

Not sure the above is true now or in the recent past. It hasn't ever applied to my AGM batteries.

I just read the EnerSys Odyssey owner's manual and the only reference to car charging was for storage purposes. With 12.84 volts indicating 100% charge, the battery can be stored for two years or until it reaches 12 volts and then re-charged and made ready for service.

The only reference to vehicle supplied charging power was related to V-twin motorcycles and stator/alternators providing 32 amps or less of power. Other than that, and from my own experience, install it and forget it if it's a daily driver. If it sees use only every few weeks, I put it on a AGM specific maintenance charger.

Mine have lasted for many years without any further work involved and certainly not boosting amperage or voltage as suggested above.

 

I ran an AGM 27F in my FZJ80 for 5 years & never had an issue. When I sold it, voltage was 12.8 right after killing it & it would take 3 days before it dipped to 12.3V.

 

What's interesting to me is that the Odyssey warranty info specifically states alternators must output 14.0 volts minimum and 14.7 volts maximum and to see their additional documentation for temperature variances. I've got an email in to my contact there to ask if they a) have an opinion on this and b) would it void a warranty on the battery if the alternator had to be/was modified to accommodate the voltage change.

If it's something that needs to be done for deep cycle use with lights/refrigerators/stereo systems/large loads/etc. why would there not be a more widely seen mention of charging voltage? My guess is the majority are used simply for starting and that being at 75% +/- of capacity is good enough. :shrug: