Advice Wanted! Dual Battery/Solar Set Up
- Thread starter kins18q
- Start date
dwh
Tail-End Charlie
They all work. And after around 500 cycles down to 0% state of charge, they all die.
Last time I bought two group 31 deep cycle batteries - one to use as the starting battery - from O'reilly that were made by um...East Penn. But they have the SuperStart name on them. They have the same part number, but with a J at the end and those are made by Johnson Controls. I paid a bit extra and ordered the East Penn version. I guess coming up on two years now and still working fine (the starting battery would be of course - I don't thrash that the way I do the deep cycle). I'd guesstimate the deep cycle is still at around 80% of the original 115ah capacity, but that's just a WAG - I haven't actually been keeping track of it. I just buy 'em, ignore 'em and use 'em up. Babying batteries is not one of my favorite camping activities.
I'd wonder how long they've been sitting around, and what the state of charge is. If they've been sitting at a lower than full state of charge, they'll be somewhat sulfated. Still, with flooded batteries you could probably blow the rust off the plates with a good EQ cycle, so I'd be temped at that price.
I wondered that myself and asked the guy how to tell how old a battery was. He told me that the battery has a manufacturer's code that can be looked up. I didn't pursue it beyond the question. I'm in the process of figuring out what I need to do my project. Thanks for the info, didn't mean to hijack the thread.
WOW guys amazing info! I ended up listening to you guys and going with 2 100w flexible panels. They will both fit on the rooftop box. 100 ah battery, solenoid, 20amp PWM charge controller...Still need to pick up wires and fuses. My fridge is shipping, can't wait to get this all up and running.
I am making reflectix panels that velcro to all windows when not driving. Will probably put some reflectix on the fridge itself too. Hoping to fit it between the front seats, so it will see more sun than if it were in the back hiding behind the tint.
I love the idea of using the battery down to 0%... but I don't really know how much driving we will be doing, and if the alternator will be able to charge the battery. I love this idea if we were just headed out for weekends or week long trips and had a place to charge up in
I am making reflectix panels that velcro to all windows when not driving. Will probably put some reflectix on the fridge itself too. Hoping to fit it between the front seats, so it will see more sun than if it were in the back hiding behind the tint.
I love the idea of using the battery down to 0%... but I don't really know how much driving we will be doing, and if the alternator will be able to charge the battery. I love this idea if we were just headed out for weekends or week long trips and had a place to charge up in
You should be fine with that setup.
Currently, I have a Tacoma with an 80 (?) Amp alternator. I use a manually switched solenoid to charge my 105AH battery in the truck bed while driving. The switch is supplied by a source powered only when the engine is running. I can also charge the battery from a 100W portable solar panel or from an AC charger. My fridge is a small Dometic. So when I'm towing my dirt bike across the country, the alternator keeps the house battery charged and when I'm camped, the panel does the job. I've spent 5 days camped with the panel supplying all the power I needed.
Replacing the Tacoma will be a Transit van with a more robust solar system.
Good luck with your project, I think you'll find it does what you need.
Currently, I have a Tacoma with an 80 (?) Amp alternator. I use a manually switched solenoid to charge my 105AH battery in the truck bed while driving. The switch is supplied by a source powered only when the engine is running. I can also charge the battery from a 100W portable solar panel or from an AC charger. My fridge is a small Dometic. So when I'm towing my dirt bike across the country, the alternator keeps the house battery charged and when I'm camped, the panel does the job. I've spent 5 days camped with the panel supplying all the power I needed.
Replacing the Tacoma will be a Transit van with a more robust solar system.
Good luck with your project, I think you'll find it does what you need.
rayra
Expedition Leader
kins, IIRC your / our Suburbans have the 130 amp alternator. They come 105A, 130A, 145A.
Autozone wants $160 for a 145A, rockauto wants $126. And there are aftermarket / upgraded alternators in the police/EMS and high end audio markets. But at quite a premium.
I did a brush replacement and bearing re-grease on our Tahoe alternator at ~150k mi, 165k+ now, still kicking, I was going to suggest just buying the higher output alternator as a replacement when you current one dies, but who knows when that'll happen. You'd have to really do the math to see if that 15A difference in alternator capacity really matters in your situation, particularly since you have two panels now.
I'm curious about your saying fitting the fridge between the front seats, there can't be more than 12" between them, I've never seen a fridge that narrow and don't they need to breath on the side(s)?
Autozone wants $160 for a 145A, rockauto wants $126. And there are aftermarket / upgraded alternators in the police/EMS and high end audio markets. But at quite a premium.
I did a brush replacement and bearing re-grease on our Tahoe alternator at ~150k mi, 165k+ now, still kicking, I was going to suggest just buying the higher output alternator as a replacement when you current one dies, but who knows when that'll happen. You'd have to really do the math to see if that 15A difference in alternator capacity really matters in your situation, particularly since you have two panels now.
I'm curious about your saying fitting the fridge between the front seats, there can't be more than 12" between them, I've never seen a fridge that narrow and don't they need to breath on the side(s)?
dwh
Tail-End Charlie
Upgrading the alternator won't make much difference. 99% of the time, it won't be running at full capacity anyway. The resistance of the battery and wiring will regulate the amps allowed to flow through the battery. So even with a million amp alternator, if the battery is holding the amps flow down to 30a, then 30a is what the alternator will produce.
Much more important is the later model GM computer controlled temperature sensing voltage regulator. DiploStrat has that in his truck, and it makes a huge difference in getting his dual alternators to really crank out the power to the batteries. So, depending on what year they started with that smart regulator setup, you might or might not have it.
Of course, he's also using FatAss(tm) welding cable, which would make a bigger difference in shaving time off the charge cycle than a higher output alternator (IF you have the smart charging system). So if you have the smart charging system regulator, then by all means, go for some bigger wiring which will actually help more than a bigger alternator.
But even with the killer charging system, you'd still be looking at hours (4 at least) to achieve a bulk charge and then more hours (6-8) to finish off the absorb for a 100% charged battery. Without the smart regulator, you could be looking at 24-36 hours of drive time to fully top the battery up to 100%.
Best is to live with the charging system in the truck, which will do a halfway decent job of getting the battery up to 80% in a single day's driving, and then going with the max solar that can fit to top the battery up the rest of the way and keep topping it off each day.
Much more important is the later model GM computer controlled temperature sensing voltage regulator. DiploStrat has that in his truck, and it makes a huge difference in getting his dual alternators to really crank out the power to the batteries. So, depending on what year they started with that smart regulator setup, you might or might not have it.
Of course, he's also using FatAss(tm) welding cable, which would make a bigger difference in shaving time off the charge cycle than a higher output alternator (IF you have the smart charging system). So if you have the smart charging system regulator, then by all means, go for some bigger wiring which will actually help more than a bigger alternator.
But even with the killer charging system, you'd still be looking at hours (4 at least) to achieve a bulk charge and then more hours (6-8) to finish off the absorb for a 100% charged battery. Without the smart regulator, you could be looking at 24-36 hours of drive time to fully top the battery up to 100%.
Best is to live with the charging system in the truck, which will do a halfway decent job of getting the battery up to 80% in a single day's driving, and then going with the max solar that can fit to top the battery up the rest of the way and keep topping it off each day.
Glad to hear your system covers your needs, it sounds pretty similar to ours!
Took out the center console and there is more like 13 inches of room from leather to leather. The fridge is 13.75. I checked the frame on the very bottom of the leather upholstry and it is pretty pliable. I think I can bend it in to get the extra half inch on each side. I don't thinki it needs to "breathe" on the sides, but in any case it will be pretty easy to situate the little vent at the bottom in a possition that isn't pressed up against anything.
Here is a link to the fridge. The way I want to put it will actually have the vent near the driver's feet assuming that I can fit it. That way we can open the top towards the dash so we can access from the front seats and from the back.
http://www.equipt1.com/item/travel-box-30-liter-fridge-freezer
This is all purely speculation, the fridge hasn't arrived yet. Feels like it is taking forever!
Definitely not upgrading the alternator. We have pretty much maxed out our goal budget of 10k at this point. Saving the rest for the trip and whatever breaks on the road! More DIY to come though
This.... And I have the Bogart sc2030 charger that works with the trimetric monitor.... and it is awesome. Highly recommend.
Another Question
Thanks again everyone!
One last question, I know I have already been advised to install additional 12v sockets that are wired into the house battery and solar rather than get an inverter, do most people agree with this? I am sure I can find 12v chargers for our laptops and I have usb outlets for cell phones.
Is it much more efficient to run everything off 12v rather that use an inverter?
If I do end of needing an inverter for, do I need pure sine for the laptops/camera batteries and mayyybe a tiny blender?
Thanks again everyone!
One last question, I know I have already been advised to install additional 12v sockets that are wired into the house battery and solar rather than get an inverter, do most people agree with this? I am sure I can find 12v chargers for our laptops and I have usb outlets for cell phones.
Is it much more efficient to run everything off 12v rather that use an inverter?
If I do end of needing an inverter for, do I need pure sine for the laptops/camera batteries and mayyybe a tiny blender?
DiploStrat
Expedition Leader
Yes!
Hard to tell. Unfortunately the usual way that you learn that you DO need PSW is by watching the smoke come out of your appliance.
luthj
Engineer In Residence
For low power devices 12V native chargers will use half the power of the inverter+AC charger.
Most electronics use switching type power supplies when powered from 120V (battery chargers as well). These power supplies will happily run on a modified sine inverter (most of them at least).
Devices with induction loads (all AC motors) will pull more power and run hotter when used with a modified sine inverter vs a pure sine unit. That being said, short run times are generally not a problem.
If you need an inverter, get the smallest unit that will meet your need. Inverters are more efficient running above 50% of their rated output. Another option is a small and cheap 200W inverter for your electronics (the ones you cant get 12V chargers for). If you need to run a blender, a second larger inverter would run this unit. Even when not powering anything the inverters will use power (some more than others). So turn the inverter off whenever you are not using it.
Most electronics use switching type power supplies when powered from 120V (battery chargers as well). These power supplies will happily run on a modified sine inverter (most of them at least).
Devices with induction loads (all AC motors) will pull more power and run hotter when used with a modified sine inverter vs a pure sine unit. That being said, short run times are generally not a problem.
If you need an inverter, get the smallest unit that will meet your need. Inverters are more efficient running above 50% of their rated output. Another option is a small and cheap 200W inverter for your electronics (the ones you cant get 12V chargers for). If you need to run a blender, a second larger inverter would run this unit. Even when not powering anything the inverters will use power (some more than others). So turn the inverter off whenever you are not using it.
dms1
Explorer
What chargers are 12v to 12v? All the chargers I saw on the NOCOweb site run off of AC 110V
77cruiser77
Observer
I too suggest you change your batteries. Not to a specific brand but to AGM. You will want a sealed battery if its stored inside your vehicle as the off gassing from conventional batteries is deadly stuff.
I'm building a similar system and will be using a small pure sine wave inverter. Doesn't work out every time but to give a general idea if the cord from device plugs directly into an outlet it probably needs a pure sine wave. if however it goes through a transformer (laptops, camera batteries, headlamp, etc) then a modified sine wave is all thats needed.
I'm building a similar system and will be using a small pure sine wave inverter. Doesn't work out every time but to give a general idea if the cord from device plugs directly into an outlet it probably needs a pure sine wave. if however it goes through a transformer (laptops, camera batteries, headlamp, etc) then a modified sine wave is all thats needed.
mmaattppoo
Adventurer
CTEK sells the D250S Dual 12V DC to DC multi-step smart charger. This product includes the ability to charge a house battery from both your vehicle's alternator and from solar panels using an inbuilt MPPT solar charge controller. This product is readily available in Canada and the States through the usual online sources.
There are other products out there but I'm not sure about their availability in North America.
I've been running the D250S Dual in my Jeep to charge a Northstar 76 Ah AGM deep cycle marine house battery for almost two years and more recently with 150 Watts of rigid monocrystalline panels. Charging from the alternator is at a maximum of 20 amps unless you opt for the Smart Pass add on which bumps the maximum charging current from your alternator up by an additional 80 amps (100 amps max total). Charging from the solar panel is limited by the capacity of the panels (minimum of 40 Watts I believe) and solar irradiance and environmental conditions.
For my setup (pictured below) I've seen charging currents of up to 6.5 - 6.9 amps from my panels under clear sky mid-day summer sun. These values decrease when the sun is lower on the horizon
Solar Panels
D250S Dual, inline power monitor, distribution panel, and house battery.
Based on my usage (primarily a 37 qt ARB fridge/freezer at approximately 312 Watt•hr per 24 hr period) my panels take approximately 4-5 hrs to recharge back to 100%); easily achieved where and when I tend to camp (southern British Columbia in the late spring and throughout the summer). YMMV. More sun, higher capacity panels, and/or a larger capacity battery would allow you to harvest more power each day and ride out days with less than ideal solar charging conditions.
I also hardwired a CTEK Multi US 7002 battery charger to my starting battery (pictured below) for the occasions when I have access to 120 Volt mains shore power. The battery charger charges the starter battery and the house battery (through the D250S Dual).
Battery Charger
NOCO weather resistant socket for plugging extension cord into battery charger.
Hope this helps.
Cheers.
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