Lowest Starting Voltage?

[SnoViking]

Hey All, I've done some research and haven't quite come across what I'm hunting for. (I'm not sure if I'm wording it correctly either though)

Does anyone know, or have any experience;

What is the lowest voltage is needed for a 3rd gen to crank.
(I'm not talking about cranking over as if it's out of fuel. My truck usually kicks off as soon as the stated engages).

Is there a cut off (i.e. 11 volts) and the starter solenoid won't kick?

I ask because I am in the process of shopping for a fridge. Most of them have built in cut offs at a preset voltage (I've seen all the way down to 10.5 VDC, but they're adjustable). I'd just like to get some insight before I go messing around and possibly get stuck.

Thanks in advance!

 

[KidVermicious]

There's no set number, too many variables. You should be carrying a little lithium ion jump pack anyway and then you won't have to worry about it.

 

[nobb]

Too many factors other than just voltage. Voltage also isn't a good indicator of how much current your battery can supply.

 

[SnoViking]

Thanks for the insight. I know the basics, the power is in amps, and not volts, but I wasn't sure if there was a cut-off below a certain threshold where it won't even try to crank.

I was planning on picking up one of the little power bank jump starters just for an "emergency".

 

[TXLX1]

http://www.arttec.net/Solar_Mower/4_Electrical/Battery Charging.pdf

This should give you an idea of resting charge % and volts. Anything under 11V is probably going to give you a real slow crank. You really don't want to run a standard car battery under 12V repeatedly, they are designed to start the car and be charged and be used when the vehicle is running.

I use fridges in both of my trucks. Have a deep cycle in 1 and an oversized standard battery in the other, but monitor the voltage on that battery closely.... You can buy one of those cigarette voltage meters or a hard wire one for cheap. And great idea to carry a small jump pack... can use for jumpstart, charge devices, etc.

 

[SnoViking]

Awesome! That's a great article.

So adding that to a bit more research I came up that I really shouldn't drop below 11.5V at 65-85 degrees at my predicted rate of discharge. Anything below 11.5 will drop me below a 50% state of charge and start to wreck my battery.

I'm planning on adding a 100w solar panel to put some watts and Amps back into the system to negate the fridge draw during the day when it's sunny and warm. Eventually I'll end up with a dual battery setup but until then I wanted to learn more.

��

 

[TXLX1]

Awesome! That's a great article.

So adding that to a bit more research I came up that I really shouldn't drop below 11.5V at 65-85 degrees at my predicted rate of discharge. Anything below 11.5 will drop me below a 50% state of charge and start to wreck my battery.

I'm planning on adding a 100w solar panel to put some watts and Amps back into the system to negate the fridge draw during the day when it's sunny and warm. Eventually I'll end up with a dual battery setup but until then I wanted to learn more.

��

You may want to look at AGM or deep cycle batteries versus a dual setup, depending upon your needs. I have a group 31 deep cycle in my LX and it has tons of power, I never really worry about the fridge on it as long as I start the truck up once a day.

The 4runner is a little more tricky, I know a group 31 agm or deep cycle will fit, but the cabling and/or terminals will have to be modified. There is one company that makes a 27f AGM battery (no modification to cables but the battery is pricey) and that's what I plan to install in the 4runner next and run a single battery.

 

[idlingmike]

Be very careful doing this based on voltage if you're in the middle of nowhere. Batteries can have a good surface charge and drop like a rock as soon as it sees load. I'll second the previous reply about carrying a small lithium jumper pack in these situations.

 

[SnoViking]

Yup. I already have one on order. Found a decently priced one on Amazon that says it'll do up to 500cca and got a bunch of good reviews. . Should be good to get me going If I kill my battery.

I'm hunting down options for an AGM battery. It looks like Optima makes a yellow top in the 27 size that has the correct terminal configuration. I think Enersys makes one also.

Be very careful doing this based on voltage if you're in the middle of nowhere. Batteries can have a good surface charge and drop like a rock as soon as it sees load. I'll second the previous reply about carrying a small lithium jumper pack in these situations.

 

[idlingmike]

Avoid the red top Optima's. I can't speak for the yellow tops, but I've had a number of red tops over the years, none lasted very long.