Biggest battery in stock location?

Thanks. I think I would rather go the single bigger battery route over the more expensive dual battery route.

 

Hi, can the stock alternator charge the group 31? I was told it can not, can you confirm?

 

The 3rd gen stock alternator won't charge an AGM battery to 14.7V. But you can charge it on a 7/8 stage charger once a month to keep it happy.

They have a 20A too.

https://www.vmaxtanks.com/BC8S1215A-12V-15A-8-Stage-Smart-Battery-Charger-Maintainer-_p_218.html

 

If the stock alternator will not fully charge a group 31 battery are you guys/gals changing the alternator?
Will the stock alternator fully charge a group 27 battery?

 

Or add a solar panel. I’m debating either going dual battery or just a larger main batter and a solar setup.

 

Got one of these for all our AGM batteries. Love it! If your spending a good amount on a AGM battery make sure your getting a good charger also. Most AGM batteries need more juice than the Taco alternator can put out.
https://4xspower.com/shop/charging/intelli-chargers/1005-121416v-battery-intellicharger-5a-15a-25a/

 

The group "size" is just that. It's the physical size of the battery. A group 27, 35, 65 has nothing to do with amps/volts/charging/reserve capacity/ability to run a refer, dildo, or razor...wait....no dildos. It's just a standard used to fit batteries into trucks and cars.
Zim

 

My background is Medicine and the above comment did not make sense to me. If it has "nothing to do with amps/volts/charging/reserve capacity/ability to run a refer, dildo, or razor..." then why get a "bigger" battery? I thought the goal was to get more reserve capacity and longer use before it needs recharge otherwise a smaller, group 24, would work just as well as a group 31 !!!!
I do understand that in order to get more "capacity" it has to have more or bigger cells therefore needing to be bigger in physical size.
Please educate me on this subject or point me to an article/book etc if the explanation is too lengthy for the forum.

 

Here is a prime example of this misconception.

Advance Auto Parts sells (2) Group Size 27 batteries;

27M is 8.8"x12"x 6.8" has 800 cold cranking amps, and 182 minutes of reserve capacity. It is a AGM battery.

27F is 8.8"x 12" x 6.8" has 710 cold cranking amps, and no reserve minutes. It is a normal car/truck starting battery

Autozone sells (2) Group Size Batteries;

27 is 8.8" x 12" x 6.8" has 810 cold cranking amps, and no reserve minutes. It is a normal car/truck starting battery

27M is 8.8"x 12"x 6.8" has 800 cold cranking amps, and 182 reserve minutes. It's a AGM battery, same as the Advance battery.

All these batteries are the same size (27) but 3 of them have different capacities and abilities. Here is the bottom line. Toyota will design a specification for the electrical needs of the truck, and the "space" available and come up with a "group size" to fit it. If you want to add another battery to run all your accessories, you should do your research with a professional shop, person to help you determine what you need.

While regular lead acid batteries need a topping charge every six months to prevent the buildup of sulfation, AGM batteries are less prone to sulfation and can sit in storage for longer before a charge becomes necessary. The battery stands up well to low temperatures and has a low self-discharge.

Deep Cycle AGM:- AGM batteries should be charged using a charger with a mode switch for AGM type batteries. It is recommended to use a charger, current limited to 20% or 0.2C of the batteries capacity at a charging voltage of between 14.6 – 14.8V following deep cycle use, or 13.6V – 13.8V for standby use.

Here is the argument. Toyota alternators will not charge between 14.6 and 14.8V. You will need additional charging methods like solar or battery tender like I have, in between trips to the mountains.

There is a dual battery thread here that is really good and I encourage everyone to go see it.
https://www.tacomaworld.com/threads...ts-see-them-multiple-batteries-thread.295653/
and also ken the electrical guy;
https://www.tacomaworld.com/threads/ken-the-electrical-guy-q-n-a.632969/

 

Thanks for the information. It's starting to make sense. There are many hours worth of information in the 2 threads you recommended. Looks like I have a lot of reading homework to do.
As always, the information found in this forum is amazing and so easily shared by everyone.

 

As far as replacing the oem battery, i'd just buy a deka of the same size and be done with it for years.

 

Trying to setup a system for my fridge/ DD tacoma.. 2016 I currently have a stock battery, and am drawing off it for a winch, lightbar 20" BD driving light, 2 CaliRaised LED ditch lights, and as soon as I have the appropriate wiring (6AWG cable to a 4 circuit fuze block in the bedside cubby), I will have power for my ICECO VL60DZ (45W draw), and 2 USB ports in the bed.... and 12v source for my diesel heater.

I heard there is a simple solution to the oil filler neck to be able to run a group 31 battery, as the oil cap will screw directly into the valve cover... can anyone confirm this?

and I also am looking to use the factory battery tray to hold an G31 X2 AGM. I understand I will need longer J-hooks.. and not really concerned with the extra 30lbs of battery...