Goal Zero Vs. Dual Battery Vs. Solo Group 31
- Thread starter markwin
- Start date
If the battery is literally dead e.g. shorted then it may need to be disconnected for anything to work.
In case you were serious, the rolling vehicle in gear spins the alternator enough to generate a spark and engine roars to life.
Then you just have to get driving to recharge or buy a replacement batt, remembering not to turn off the engine in the meantime.
In case you were serious, the rolling vehicle in gear spins the alternator enough to generate a spark and engine roars to life.
Then you just have to get driving to recharge or buy a replacement batt, remembering not to turn off the engine in the meantime.
shade
Well-known member
What's more fun is having a dead battery and alternator, with an electric fuel pump. The fuel pump was powered directly from the alternator, so even with a charged battery, it wouldn't run. To drive it home, we had to run a jumper directly from a charged battery to the fuel pump, and we went through three batteries to keep it powered enough for lights (it was night, of course) and ignition. It was interesting to drive right before the battery went flat, chugging down from 4-3-2 cylinders firing.
Yes an alternator dying is a lot more serious these days, and an other-means-charged battery doesn't get you far.
Could use an AC genset and mains charger I suppose.
Still, consider electric-only vehicles, stranded far from mains power, maybe need days after they get there if a 15A 110V circuit is all that's available.
Range anxiety indeed
Could use an AC genset and mains charger I suppose.
Still, consider electric-only vehicles, stranded far from mains power, maybe need days after they get there if a 15A 110V circuit is all that's available.
Range anxiety indeed
kalieaire
Observer
Yes an alternator dying is a lot more serious these days, and an other-means-charged battery doesn't get you far.
Could use an AC genset and mains charger I suppose.
Still, consider electric-only vehicles, stranded far from mains power, maybe need days after they get there if a 15A 110V circuit is all that's available.
Range anxiety indeed
I definitely love the idea of a hybrid system for offroad vehicles.
Honestly I'm driving in RWD 95% of the time. I go into 4 LO when I get stuck or I'm on an incline and I can't move w/o stalling. 2-Lo would get me 4.9% of the way there. The .1% of the time is if I end up rock crawling.
A typical hybrid system would be useful because FWD could be electric assist and RWD would be all other times. The advantage of a electric traction motors is you get 100% of the torque the entire time. They're literally the best option for rock crawling or going over obstacles in a slow and controlled manner.
In fact, I don't understand why Toyota's Rav4 isn't more capable with its hybrid system. It could literally be used to rock crawl in a stable fashion, instead it drives like a really typical automatic car w/o low range gearing over stuff.
Anyway, getting off topic.
Group 31 ******. Keep it simple, stupid.
If you mean just one battery for both uses, and need AGM, the Odyssey PC-2150 is a great G-31 choice.
Personally I'd use two and
isolate the Starter with an adjustable LVC,
setpoint a bit above the voltage where cranking starts laboring.
Then set as my goal never dropping below that voltage except in a "rare exigency".
That way the two wear as evenly as possible, get
double the CCA as well as maximum amps for high-amp House loads,
but at **half** the C-rate stress so less V sag
full benefit of Peukert's Law for maximum Ah capacity for House loads, more like 250 rather than 200Ah, and best of all,
overall half as deep DoD% cycling, so the pair lasts **much** longer, maybe a full decade
Best of both worlds at minimum extra cost. . .
Personally I'd use two and
isolate the Starter with an adjustable LVC,
setpoint a bit above the voltage where cranking starts laboring.
Then set as my goal never dropping below that voltage except in a "rare exigency".
That way the two wear as evenly as possible, get
double the CCA as well as maximum amps for high-amp House loads,
but at **half** the C-rate stress so less V sag
full benefit of Peukert's Law for maximum Ah capacity for House loads, more like 250 rather than 200Ah, and best of all,
overall half as deep DoD% cycling, so the pair lasts **much** longer, maybe a full decade
Best of both worlds at minimum extra cost. . .
Brainfart there sorry, Starter kicks over
With a small/light car, don't even need a hill, used to push start by myself on the flat, even on dirt roads.
Don't let it get away from you though, sent a Mazda station wagon down into a bush ravine that way once.
Better with others helping of course.
I take it you're pretty young? Heck I used to help my Dad start his Model A **hand** cranking!!
With a small/light car, don't even need a hill, used to push start by myself on the flat, even on dirt roads.
Don't let it get away from you though, sent a Mazda station wagon down into a bush ravine that way once.
Better with others helping of course.
I take it you're pretty young? Heck I used to help my Dad start his Model A **hand** cranking!!
shade
Well-known member
I like it.
What about going cheap and FLA with a pair of Sam's Club Duracell/Deka GC2s in a similar arrangement? Carry a jump pack in the event a fault drops the main battery out of 12V, of course.
Iirc someone already mentioned this, but a significant issue with any dual battery installation under the hood of a Toyota Tacoma is the stress of all of that weight. The worst of the options is the side-by-side arrangement of a pair of G31 batteries in the OEM location. Over time, even if the truck never leaves pavement, there's a good chance that the supporting structure will crack and fail from having 150 lbs of lead focused in that spot.
shade
Well-known member
I've hand cranked an air-cooled Wisconsin engine many times. It absolutely sucks. I never got bit by the detachable crank, but it was always a concern.Brainfart there sorry, Starter kicks over
With a small/light car, don't even need a hill, used to push start by myself on the flat, even on dirt roads.
Don't let it get away from you though, sent a Mazda station wagon down into a bush ravine that way once.
Better with others helping of course.
I take it you're pretty young? Heck I used to help my Dad start his Model A **hand** cranking!!
Yes self-building mudbrick houses off grid, had a concrete mixer on a trailer powered by this huge old single-cylinder Lister from the 30's maybe even older.
50-lb flywheel with a folding inset crank handle held in with a bit of fencing wire. Almost rip your arm off cold mornings, and if that handle didn't fold in, we'd make a fence around that end or it would break legs for sure.
OSHA would not have approved
50-lb flywheel with a folding inset crank handle held in with a bit of fencing wire. Almost rip your arm off cold mornings, and if that handle didn't fold in, we'd make a fence around that end or it would break legs for sure.
OSHA would not have approved
Yes depends on the truck of course, could weld-reinforce proactively.
But with just a parallel pair, the intra wiring can be long, as long as it's thick, say 2-3/0 AWG?
so can mount one or both halves under-carriage, on the bumper with the winch, wherever you like, really.
> What about going cheap and FLA with a pair of Sam's Club Duracell/Deka GC2s in a similar arrangement?
Sure but big advantage with my scheme, is that the same model batteries comprise both the "Starter sub-bank" & the "(rest of) House" halves, same mfg datestamp, great redundancy, ideally both wear evenly, get retired at the same time down the road as I said maybe a decade, carry over from old truck to the next one
Which of course you **could** do with FLA GCs, plenty of oomph for cranking, but many here won't believe it and prolly not what you meant.
Is there room in the stock Starter batt tray for 2x 6V 215Ah GCs?
> Carry a jump pack in the event a fault drops the main battery out of 12V, of course.
Those are failsafe 3rd level belt & suspenders for sure, not primary backup.
shade
Well-known member
Yes depends on the truck of course, could weld-reinforce proactively.
But with just a parallel pair, the intra wiring can be long, as long as it's thick, say 2-3/0 AWG?
so can mount one or both halves under-carriage, on the bumper with the winch, wherever you like, really.
> What about going cheap and FLA with a pair of Sam's Club Duracell/Deka GC2s in a similar arrangement?
Sure but big advantage with my scheme, is that the same model batteries comprise both the "Starter sub-bank" & the "(rest of) House" halves, same mfg datestamp, great redundancy, ideally both wear evenly, get retired at the same time down the road as I said maybe a decade, carry over from old truck to the next one
Which of course you **could** do with FLA GCs, plenty of oomph for cranking, but many here won't believe it and prolly not what you meant.
Is there room in the stock Starter batt tray for 2x 6V 215Ah GCs?
> Carry a jump pack in the event a fault drops the main battery out of 12V, of course.
Those are failsafe 3rd level belt & suspenders for sure, not primary backup.
The Tacoma is pretty flimsy up front and would require extensive work to reinforce the OEM location for a second battery; 150 lbs is a lot to ask of the fender liner and front framework. I haven't seen under the hood of a 3rd gen, but there may be enough space on the passenger side of the engine bay to locate another battery. When I was considering adding a house battery to the exterior of the cabin of my truck (2nd gen Tacoma), I decided that I'd probably be better off with it tucked under the truck bed. The same may be applicable to a 3rd gen.
The dual GC2 idea had more to do with finding the cheapest, hardiest solution for the most Ah. At their cost and with their construction, wear issues wouldn't be as important as with pricier alternatives. I'm pretty sure that set up would be able to spin the 3.5L engine in a Tacoma just fine. There may be room for two squeezed into the OEM location, but it'd probably be close on height. The weight would still be a problem, though.