At what point do you install a dual battery system? (1 Viewer)

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Call me a +1 on the portable battery versus hard wired. You may get a little more bang for the buck on a built in system, but being able to take a GZ into the house for power outages or to campsite away from the car is primo. If you are worried, get a high CCA agm as your primary and top it off with a good charger once a month.

but honestly, I doubt you would need it.
 
Solar panels can also be used for dual battery systems. I have a solar panel and use it to keep the auxiliary battery charged when I'm camping and don't want to move my car.
 
When do you make the call whether or not to go with an aux battery?

I want to install lights, radios, more AC output power, winch, fridge, etc(do I need 2 batteries to run all this stuff?). This would happen over time, but I would hate to get the lights and radios done for example and then have to re run the wiring to an aux battery setup.

I want to say, ok fine just make the dual battery the first thing that happens. But then there's really no load on it.

What would you do?

Dual battery for sure. Especially from the point you add a fridge onwards. Even fixed radios can draw quite a few amps at full blast. My ICOM 5100 draws up to 13 amps at full power TX!! That's quite a bit more than my fridge (~6 amps when compressor cycles), and your starter (main) battery will not like it with the vehicle off.

Plus you get the safety net of cranking your main battery in case you face a problem down the road
 
We've camped in a travel trailer, tents, park cabins etc... for years-and probably have seen it all.

We now have a goal zero 1500X AND a 2nd group 35 battery charged by a Redarc BCDC 1225D AND a Merlin XP170 folding solar array. All acquired in the last year in preparation for upcoming trips.

Why: because with power you can call for help, jump start your car or someone else's, have light and cooling, cooking, refrigeration and probably a dozen other things.

If you have power you almost have it all, IMHO.
 
A somewhat related question

How long do you guys run say just the radio with the engine off. Or run the entertainment system.

I know we are talking more overland/camping, but with 3 kids and numerous activities and softball games and soccer practice too, sometime the car becomes a mini-living room for the younger ones. This also is the case when camping...when there is some delay or bad weather sometimes you just have to hunker down in the car.

I know you can turn the ignition on occasionally ....(which turns off everything momentarily and can set off a cranky 2 year old)
Or leave the vehicle running which I prefer not to do especially when at a public space like a park
Yes you can give them an iPad but batteries can be low and curious fingers can go from youtube mickey mouse clubhouse to some snuff video pretty quick (jk)

I am planning to add a 2nd battery so that I can:
Use it as a mini living room occasionally
I can leave work lights on when setting up camp without having the engine running
I can use my compressor and accessories without worrying too much
Have a backup system in case something drains the battery and I can jump start the starter
Hook up my 150W solar panel blanket and trickle charge the aux battery while at the campsite
And when the kids are all grown up maybe convert the back into a drawer, fridge area

I hate when the kids turns on a dome light or something at the campsite and forgets to turn it off and we are faced with a dead battery the next day.
Our portable battery jump pack usually had 1 or 2 attempts before that is drained....
You don't always have friendly neighbors around that can jump your car....
 
Those seem like good reasons.

My wife has killed a couple of car batteries from listening to the radio with the car off.

Related topic: power drain from lights. I am a huge fan of LED lights because of incandescent lights killing the battery on my 80 series when camping many years ago. Since then, I always upgrade to LED lights and I’ve never had it happen since. The 16+ has a lot more LED lighting but the 08-15 can benefit from swapping the lights out for LEDs. They’ve become super affordable too...
 
A few things worth being aware of, all from my personal experience with dual batteries:
- dealerships will blame absolutely every problem on the "complicated, custom electrical work"
- detailers will refuse to wash the engine bay due to "complicated, custom electrical work"
- you can't take it with you to your next vehicle, and re-selling it will incur huge losses
 
A few things worth being aware of, all from my personal experience with dual batteries:
- dealerships will blame absolutely every problem on the "complicated, custom electrical work"
- detailers will refuse to wash the engine bay due to "complicated, custom electrical work"
- you can't take it with you to your next vehicle, and re-selling it will incur huge losses
Hmmm.... I took my dual battery setup from my last 200 to this 200. My local dealer never commented on my battery setup. My dealer has never washed any car for me. Sounds like we’ve had very different experiences.
 
How long are you going to sit still at one point without running the truck? That’ll answer your question on if / when you need a dual battery setup.

I did the dual battery setup on my 100. Spent lots of time and money and added weight in the engine bay.

In the 200 went with a single grp31 battery and a 100w solar suitcase and a lithium jump pack. Cheaper simpler and reliable. The group 31 could run the fridge for two full days with no solar. Arrive to camp Friday night. Leave sometime Sunday.

With solar could run for a 3-4 day weekend depending on time of year and how much sun.
 
I have a 2011 tundra and the 200. I also have the arb fridge.

I didn't want to pay for 2 dual battery setups as I use both to go camping depending on where I go.

I just bought power inverter plus 120 w solar suitcase to charge during the day. Works well for me and most importantly it's versatile since I do weekend camping with both vehicles.
 
If you want a dual battery system without the "complexity" of a dual battery system I'd recommend the National Luna Power Pack. They have two versions, one that uses an old school solenoid and another one that uses a DCDC charger. It is essentially a dual battery system in a box, all you need to do is add your favorite flavor of battery. It's also easily moveable from vehicle to vehicle or can be used as a portable system like a Goal Zero unit. I think it's kind of the best of all worlds between a dedicated engine bay mounted dual battery system vs a Goal Zero. I bet if you slapped a big LiFePO4 (iron not ion) it would be pretty awesome, robust and offers longer life than the typical AGM setup. Another point is that with engine bay mounted systems you can't really run a lithium battery in there as the operating temperature range is more narrow, it doesn't like too hot nor too cold. By mounting it in a box in the cargo area or footwell the vehicle at least has some insulation and you can control the in cabin temperature. The problem with the Goal Zero units is that they still use Lithium ion batteries vs lithium IRON and the batteries are technically not linked and you can't jump yourself from it.

 
Wow, lots of good responses! I'm feeling like it's almost not worth the effort and weight gain to go through a full dual battery install though. I'm liking the solar suitcase option for sure.
 
Portable systems are great until the day you forget to move them to the vehicle you are using that day and have the rare situation where you need them.
 
Most of the portable systems do not have a 12V input other than via a cigarette lighter - i.e. you can only charge at a very low rate from your car (2-7amps/hr. Your cigarette lighter is supplied via 16-18 gauge wire so it can't handle much in the way of current). Depending on how long you are driving each day, this may or may not fully charge up your portable solar generator/Goal Zero/Jackery. A dual battery set-up benefits from a DC/DC converter that will charge the battery at rates of 30-50 amps/hr (maybe more). So your 100Ah battery will charge in 2-3 hours at the wheel and be ready to go when you hit camp or the tailgate event - whatever. You need to carry a lot of solar panels to charge your solar generator that quickly - assuming you have the sun with you - plus the expense of the panels. While I think solar is a cool concept (free energy from the sun) it does come at a price - the cost of panels and diminished payload space. I watch a lot of the YouTube overland channels who hawk Jackery and the rest and everyday they are laying out 3-4 solar panels to juice their systems. This seems like a lot of unnecessary work every day you're out there. This is changing tech and I am sure someone will wake up and make a Jackery-type unit that has a built in DC/DC converter to allow for fast charging while traveling - maybe they already have. That is the main reason I went with a dual battery set up over a Jackery-type unit which certainly has some KISS benefits. In my system, I ran a line from the starter battery through a battery-protect unit to the cargo area and the secondary electrical system is fully contained in the drawer system. Easily maintained, kept clear of dust/dirt/moisture and easily transferred/removed if I ever want to.
 
Most of the portable systems do not have a 12V input other than via a cigarette lighter - i.e. you can only charge at a very low rate from your car (2-7amps/hr. Your cigarette lighter is supplied via 16-18 gauge wire so it can't handle much in the way of current). Depending on how long you are driving each day, this may or may not fully charge up your portable solar generator/Goal Zero/Jackery. A dual battery set-up benefits from a DC/DC converter that will charge the battery at rates of 30-50 amps/hr (maybe more). So your 100Ah battery will charge in 2-3 hours at the wheel and be ready to go when you hit camp or the tailgate event - whatever. You need to carry a lot of solar panels to charge your solar generator that quickly - assuming you have the sun with you - plus the expense of the panels. While I think solar is a cool concept (free energy from the sun) it does come at a price - the cost of panels and diminished payload space. I watch a lot of the YouTube overland channels who hawk Jackery and the rest and everyday they are laying out 3-4 solar panels to juice their systems. This seems like a lot of unnecessary work every day you're out there. This is changing tech and I am sure someone will wake up and make a Jackery-type unit that has a built in DC/DC converter to allow for fast charging while traveling - maybe they already have. That is the main reason I went with a dual battery set up over a Jackery-type unit which certainly has some KISS benefits. In my system, I ran a line from the starter battery through a battery-protect unit to the cargo area and the secondary electrical system is fully contained in the drawer system. Easily maintained, kept clear of dust/dirt/moisture and easily transferred/removed if I ever want to.

This is probably true for the Jackery. The GZ costs more relatively but has expanded capabilities. GZ can charge 5 or 10 amps from one $39 car charger. Gang two of them for 10-20 amps charge rates. Or add the GZ Yeti Link Car Charger Module for up to 40+ amp rates. I recall at least a couple that have installed the big link charger on this board.

That said, IMO there's a preoccupation with charge rates. It really comes down to usage. I find even with heavy use supporting my family of 4 for car camping: coffee, old George Foreman (makes a great portable sandwich panini press and food warmer with a sheet of foil for easy cleanup), 5-10amps will keep up all day. I also use my GZ in my camper (did I mention it's flexibility is awesome!), where it powers all the 120V stuff: microwave, rice cooker, hair dryer, Keurig, charge laptops, TVs: all I need there is still just 5 amps charge rates (via installed solar on roof). It's easy to get caught up with more and bigger numbers. Research made it seem I needed the highest capacities, MPPT upgrade, etc. Reality is I didn't need any of that, for me.

Though everyone's use is different and it's good to have options. The GZ has good options. So does custom installed dual batts which can be anything one wants to make of it.
 
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This is probably true for the Jackery. The GZ costs more relatively but has expanded capabilities. GZ can charge 5 or 10 amps from one $39 car charger. Gang two of them for 10-20 amps charge rates. Or add the GZ Yeti Link Car Charger Module for up to 40+ amp rates. I recall at least a couple that have installed the big link charger on this board.

That said, IMO there's a preoccupation with charge rates. It really comes down to usage. I find even with heavy use supporting my family of 4 for car camping: coffee, old George Foreman (makes a great portable sandwich panini press and food warmer with a sheet of foil for easy cleanup), 5-10amps will keep up all day. I also use my GZ in my camper (did I mention it's flexibility is awesome!), where it powers all the 120V stuff: microwave, rice cooker, hair dryer, Keurig, charge laptops, TVs: all I need there is still just 5 amps charge rates (via installed solar on roof). It's easy to get caught up with more and bigger numbers. Research made it seem I needed the highest capacities, MPPT upgrade, etc. Reality is I didn't need any of that, for me.

Though everyone's use is different and it's good to have options. The GZ has good options. So does custom installed dual batts which can be anything one wants to make of it.
My goal zero YETI 1500X has a 45A Anderson Power Pole for a charging input. With the engine running, I connected it with jumper clamps to my 2nd battery (group 35 AGM) and was able to dump almost 300W into it IIRC. With the engine running there was about 14V on the 2nd battery. Without the engine running the voltage on the 2nd battery would charge the Yeti until the battery voltage fell below the charging threshold of what I observed to be about 13.6 V and charging stopped. This is no doubt a safety feature, to prevent those of us who make mistakes, from draining the main starter battery. So I could charge the Yeti really fast and run all kinds of stuff while going down the road.

Just curious: is there a regulator gizmo that will take a DC input voltage say 8-14V and output a constant of something like 13.8-14V? The idea would be to drain the 2nd AGM battery on the car to charge the Yeti 1500X WITHOUT running the engine.
 
My goal zero YETI 1500X has a 45A Anderson Power Pole for a charging input. With the engine running, I connected it with jumper clamps to my 2nd battery (group 35 AGM) and was able to dump almost 300W into it IIRC. With the engine running there was about 14V on the 2nd battery. Without the engine running the voltage on the 2nd battery would charge the Yeti until the battery voltage fell below the charging threshold of what I observed to be about 13.6 V and charging stopped. This is no doubt a safety feature, to prevent those of us who make mistakes, from draining the main starter battery. So I could charge the Yeti really fast and run all kinds of stuff while going down the road.

Just curious: is there a regulator gizmo that will take a DC input voltage say 8-14V and output a constant of something like 13.8-14V? The idea would be to drain the 2nd AGM battery on the car to charge the Yeti 1500X WITHOUT running the engine.

Yes, there are what's known as regulated DC step up transformer or boost converter. That's actually what the GZ car charger is, a small step up transformer, but it has a voltage cutoff similar to what you found, so it only functions when there's excess charging voltage.

You can do what you want with a little ingenuity as you can find those boost converters all day on Amazon. Just need to find the right one, with the right target voltage. IIRC, the GZ doesn't want anything great than about 18V. So any converter with an output about 14-18V should do. You'll want to double check my numbers as I'm just going off memory.

It'll be similar to what this guy is doing, but he's using it to boost the output of the GZ, and you'll want it to boost the output of the car to the GZ.
 
Yes, there are what's known as regulated DC step up transformer or boost converter. That's actually what the GZ car charger is, a small step up transformer, but it has a voltage cutoff similar to what you found, so it only functions when there's excess charging voltage.

You can do what you want with a little ingenuity as you can find those boost converters all day on Amazon. Just need to find the right one, with the right target voltage. IIRC, the GZ doesn't want anything great than about 18V. So any converter with an output about 14-18V should do. You'll want to double check my numbers as I'm just going off memory.

It'll be similar to what this guy is doing, but he's using it to boost the output of the GZ, and you'll want it to boost the output of the car to the GZ.

Got it. I didn't know what these things might be called if they existed at all. I'd ideally want one that would allow me to charge quickly so I'd dream of one that could do 150+ watts. Thanks!

Edit: I'd only do this If I had to as flattening an AGM battery ain't too good for it. :cool:
 

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