Large group 31 Battery with low voltage disconnect (any one else done this?)

[masphx]

My stock battery is taking a dump on my 4th gen 2003 v8. I would have just gone out an bought a stock battery size with a 3yr warranty at $120 but I'm considering this... Has anyone done this instead of duel battery setup? I don't really have plans for a fridge in the near future but possibly one a year or two off. Would be nice having the electrical system in place for it. Opinions?

Low Voltage Disconnects

This is also something I can swap into my 3rd gen as needed.

 

[Bumbo]

It's pointless buying an AGM if you are not going to cycle deep, and if you cycle that deep with a single battery setup, you won't be able to start your car either way.

I know the dude in the article is running an LVD, and go ahead and run a LVD on a single battery setup (its an awesome accessory), just save the cash and use a standard starter battery. You will end up using a higher disconnect voltage regardless. Use the saved money to buy a jump-start pack for emergency (the newer lithium/capacitor small ones, not the old school stuff).
Like This
https://www.amazon.com/NOCO-GB40-Ul...=1488050867&sr=8-2&keywords=genius+boost&th=1

There is a reason people want a 2nd battery, not just a better single battery.

Point being you have electronics(ACR) to isolate the starter from the accessory loads when the car is not running. That basically gives you absolute piece of mind that you car will start every time, regardless of the state/condition of the accessory battery. You could run that into the floor and still start the car.

I highly recommend a programmable LVD so you can actually set your disconnect voltages. Like this
https://www.bluesea.com/products/7635/m-LVD_Low_Voltage_Disconnect

Just get a good starter battery, like one of those Walmart EverStart Maxx made by Johnson Controls or a Costco Interstate battery and call it a day.

Group 27 or 24F should work out just fine. I had a group 35 in there before which was a much smaller battery.

Check dimensions and spec before buying, just because the number is higher doesn't mean its a bigger battery.

That said, if you want to pony up for an AGM for the starter go for it, its an awesome battery, you just won't be taking full advantage of what it has to offer in that configuration. For the price of that AGM, you could afford to do it 2-3 times over with a starter battery.

 

[riceandpho]

few members here are using just one group 31, i use dual group 31. but my needs are different from yours. i have the v6 tho, hopefully the v8 users will chime in.

 

[Zeimbo]

few members here are using just one group 31, i use dual group 31. but my needs are different from yours. i have the v6 tho, hopefully the v8 users will chime in.

Do you have any pics of your dual battery set up?

 

[flipflopnfly]

Yeah, I need to do a low voltage disconnect on mine. I have the 600W inverter and it drains the battery to 11.5v before it cuts off.

11.5v won't start the truck, I have to connect the jump pack to the battery if I don't monitor it closely. Thing is the LVD's I looked at are pretty expensive.

 

[Bumbo]

Yeah, I need to do a low voltage disconnect on mine. I have the 600W inverter and it drains the battery to 11.5v before it cuts off.

11.5v won't start the truck, I have to connect the jump pack to the battery if I don't monitor it closely. Thing is the LVD's I looked at are pretty expensive.

Which ones have you looked at... I thought they were really affordable in general.

How are you trying to wire it, and how much amperage are we talking about here?

 

[Bumbo]

Do you have any pics of your dual battery set up?

[MENTION=5149]riceandpho[/MENTION]

+1 on that picture request... Also curious how that is sitting in there.

I went with a 24F Starter / 34 House combo... I could fit larger, but for my AH capacity needs, I could have went smaller too.

I've seen some fenders start to cave in on heavy use rigs... Part of this was a weight savings measure in regards to not over sizing either.

I wanted to go LiFePO4 on the house side but it really complicates the setup.

 

[riceandpho]

main battery is under the hood.
my second one is in the trunk.
these are old pics and this is a different group 31, the old one i had did not need to be modify, and it was the sears die hard plat.
http://i.imgur.com/sYpO3FV.jpg

 

[flipflopnfly]

Which ones have you looked at... I thought they were really affordable in general.

How are you trying to wire it, and how much amperage are we talking about here?

I was looking at $250 and trying to be a punk to see what would come up. I haven't seen much discussion.

 

[Bumbo]

I was looking at $250 and trying to be a punk to see what would come up. I haven't seen much discussion.

Mind including a link?

That sounds wildly overpriced, and probably oversized... how big of a unit is this, and are you sure you are sizing it correctly for the application?

I also asked a question about amperage requirements... do you have an idea of what your load requirements are?

You really dont need to spend more than $50 to get a really, REALLY nice LVD that will take care of almost every load that would actually need an LVD. You can then scale from there, or even run them in parallel off the main...

 

[Bumbo]

[MENTION=5149]riceandpho[/MENTION]

Resize my good man, resize.

Imgur has a built in function for that...

I can see why you went with the 31... those were the good ole days, when Sears had those plats... too bad they dont offer then anymore, I would have stocked up on those deep. The only valid option now was to go to the people who made it for sears in the first place (Odyssey), and pay over double...

 

[hinmo24t]

It's pointless buying an AGM if you are not going to cycle deep, and if you cycle that deep with a single battery setup, you won't be able to start your car either way.

I know the dude in the article is running an LVD, and go ahead and run a LVD on a single battery setup (its an awesome accessory), just save the cash and use a standard starter battery. You will end up using a higher disconnect voltage regardless. Use the saved money to buy a jump-start pack for emergency (the newer lithium/capacitor small ones, not the old school stuff).
Like This
Amazon.com: NOCO Boost Sport GB20 500 Amp 12-Volt UltraSafe Portable Lithium Jump Starter, Car Battery Booster Pack, And Jumper Cables For Up To 4-Liter Gasoline Engines: Automotive

There is a reason people want a 2nd battery, not just a better single battery.

Point being you have electronics(ACR) to isolate the starter from the accessory loads when the car is not running. That basically gives you absolute piece of mind that you car will start every time, regardless of the state/condition of the accessory battery. You could run that into the floor and still start the car.

I highly recommend a programmable LVD so you can actually set your disconnect voltages. Like this
m-LVD Low Voltage Disconnect - Blue Sea Systems

Just get a good starter battery, like one of those Walmart EverStart Maxx made by Johnson Controls or a Costco Interstate battery and call it a day.

Group 27 or 24F should work out just fine. I had a group 35 in there before which was a much smaller battery.

Check dimensions and spec before buying, just because the number is higher doesn't mean its a bigger battery.

That said, if you want to pony up for an AGM for the starter go for it, its an awesome battery, you just won't be taking full advantage of what it has to offer in that configuration. For the price of that AGM, you could afford to do it 2-3 times over with a starter battery.

Thanks. Great input.

I have this with me, Amazon.com: TACKLIFE T8 800A Peak 18000mAh Lithium Car Jump Starter for Up to 7.0L Gas or 5.5L Diesel Engine, 12V Auto Battery Booster with LCD Screen, Portable Power Bank with USB Quick Charge: Automotive and 4 traction boards, winch soon. Run some heavy ice and cold winters in wet and snow up here so at least I'll grab a fresh regular 24.

Thanks for input everyone