2nd Battery and solar choice -- more questions

[Dust999]

I'm starting down the path of a 2nd battery install on my Tacoma. I've read most of the threads on this forum discussing batteries, solar panels, wiring and isolators....lots of great info, but, I still have some questions.

1. Battery choice.

The 2nd battery will not be used to start. Must power 50qrt arb fridge, some led lights and when needed an arb compressor. Might have to help when winching. Research points to a deep cycle battery, but there is a debate between 'thin' and 'thick' plates. Thick being better for constant discharges. I've narrowed my choices down to the following brands and models. Lots of discussion around odyssey, but does anybody have any experience or insight into vmax, rolls and northstar? Is it better to go for max 20ah capacity and RC minutes or lighter weight with less output?



2. Solar panel/s.

Is it better to go with 2x100watt panels or 1x240watt panel? Pros and cons? I'm assuming the more wattage the better? I will be standing for 2 to 3 days max, good sun exposure i.e. out southwest.

3. Isolator.

Choice is the bluesea ACR 7622

 

[dwh]

1. Rolls is one of the old big battery battery companies. Very popular with the off-grid solar crowd. Dunno anything about Vmax or Northstar. Everything else being equal, having more amp*hours capacity is better. First, you won't drain the battery as deeply under whatever your "normal use" is, which translates to more cycles of lifespan, second, Peukert effect comes into play - i.e., whatever your loads are, they will be a smaller percentage of the battery capacity with a bigger battery.

Thick vs. thin plates doesn't always apply. Some of the AGMs like Odyssey use thin plates, which is good for cranking but they can also be used for deep cycling because of the way they make the sandwich of lead plates and fiberglass fabric, so the fabric prevents the thin plates from warping and touching each other as they heat up under extended load and recharge time.

2. With solar, more wattage is always better - until you get to a point where you have more than you need. Figure out how many amp*hours you'll draw from the battery in a 24 hour period. That will tell you how much solar you need to recharge the battery in a single day of "good sun" (4-6 hours is the general estimating rule of thumb). Two panels gives you redundancy in case one gets broken or quits working - otherwise it doesn't much matter.

3. Good stuff.

 

[calicamper]

Dust
I'm building a similar set up. But no ARB. I think you only need an 80 watt panel from your description, but you go bigger on the Amp Hours stored ie larger battery. In my thread it was pointed out the ARB draw is basically 2amps per hour. One poster noted he was running his arb on a 75ah marine battery and had a 80watt solar panel, he noted full sun the 80 watt does about 4amps and in cloudy conditions 1amp conservatively etc. The 75ah battery will run the 2ah arb 3 days with no added juice.

My set up is 18ah battery in a 50cal ammo box just fits height wise, my power needs is running 1-2 amps for small Led lighting for not much more than 2-3 hrs a night then worst case maybe 9ahrs of juice from recharging small electronics.

The brains of the system if you will in my case is a $27 street lamp solar controller. Its basically a battery manager with a out put to power a light max output 20amps with a cut off at 11volts to prevent battery damage.

So in my case im driving power to a small fuse block via the power port from the controller to use the battery management aspect of the controller. My solar plan still in testing is a 10watt small renogy panel it runs around 1-1.5 amps in ideal sun and about .5 amps in shade. I may add a second one, but they are small and easily packed in a secure case etc. I figure max I need to generate 9-12amps a day solar to meet my needs. You need more like 60 amps generated during the day to both power the fridge and charge the battery to replace burned power from the night time span.

The comment about an isolater is to allow you to charge your car battery but all your powered stuff is only drawing off your secondary battery, so no dead car due to too many Margaritas mixed in the mixer the night before.

 

[Joe917]

Rolls is the best if you can afford it. Lifeline did not make your list, it should be considered. You want Deep Cycle. Period. Not marine or dual purpose or thin plate AGM marketing crap. Deep Cycle.
As far as amp/hrs the more the better. Better quality high amp/hr batteries are heavy. beware any lead acid battery claiming high numbers with low weight.
Excess solar is better, you will always get stretches of poor sun.A large panel is generally less expensive than two smaller panels of equal wattage. Large high voltage panels are even cheaper (ie 48v) and will allow smaller wiring but will require an MPPT controller which you would not need for 18v panels. More important for a full time rig over 500watts. A high quality charge controller installed close to the battery bank is important. You can't go wrong with Morningstar.

 

[Dust999]

Adding these batteries to the mix.



They mention that this the only 'true deep cycle' battery available on the market. The T1275 is big, but might fit behind the rear seat.

Thx for the feedback.

 

[calicamper]

For kicks and reference

This is my basic gear
With lights and wiring Im pushing $260 invested
The solar charge controller is impressive for $27 It manages the battery in the same manner the 15amp $400 unit on my boat does.
https://www.amazon.com/gp/product/B00NCTST4U/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1
https://www.amazon.com/gp/product/B00A82A3RK/ref=oh_aui_detailpage_o06_s00?ie=UTF8&psc=1

https://www.amazon.com/gp/product/B00QMTAZ1W/ref=oh_aui_detailpage_o05_s00?ie=UTF8&psc=1
https://www.amazon.com/gp/product/B00JXPE7IO/ref=oh_aui_detailpage_o04_s01?ie=UTF8&psc=1

ATV light tested at 1amp
https://www.amazon.com/gp/product/B00GJKXW8M/ref=oh_aui_detailpage_o04_s01?ie=UTF8&psc=1

 

[calicamper]

I have two group 31 trojens in my boat, they are heavy big and might be way over kill unless you have limited solar capability.

 

[Dust999]

Rolls is the best if you can afford it. Lifeline did not make your list, it should be considered. You want Deep Cycle. Period. Not marine or dual purpose or thin plate AGM marketing crap. Deep Cycle.
As far as amp/hrs the more the better. Better quality high amp/hr batteries are heavy. beware any lead acid battery claiming high numbers with low weight.
Excess solar is better, you will always get stretches of poor sun.A large panel is generally less expensive than two smaller panels of equal wattage. Large high voltage panels are even cheaper (ie 48v) and will allow smaller wiring but will require an MPPT controller which you would not need for 18v panels. More important for a full time rig over 500watts. A high quality charge controller installed close to the battery bank is important. You can't go wrong with Morningstar.

Added lifeline.

 

[AndrewP]

The needs you describe are *roughly* 40-50 Amp hours per day. So 1 solar panel in the 120 watt range will pretty much fulfill your needs. Of the choices you state, I would get 2 100 watt panels. Look for "12 volt panels" which are really roughly 17- 20 volt panels unless you want to buy an expensive MPPT controller. Otherwise you can use a PWM controller. Morningstar SunSaver is good, and reasonably rugged for $50. A 200 watt system would give you plenty of power most days for your stated needs. In fact you could probably get away with 100 watts if careful. Now park in the shade or a rainy day and all bets are off.

Regarding batteries, I have given up on expensive batteries. For me, little extra performance with lots of extra cost. Flooded lead acid marine batteries have worked well. I could be talked back into nice batteries, but for the last several years, I've had good performance from the Costco Marine Grp 27 batteries. 100Ah, $80 or so. So in the average day, you discharge is 50% and recharge it on solar. It's actually a little less, because your fridge runs the most when the panel makes it's peak power and so not directly discharging the battery, but consuming solar power as it is produced. If I was travelling full time (not a working stiff like everyone else) I'd have the best AGM batteries I could find. If you want to be practical though, you can spend a lot less.

Regarding your "isolator". It's a charging relay that isolates your batteries, not the old school diode based "isolators" that prevent a full battery charge on #2. In my view, the Blue Sea ACRs are the deal of the century in relay based battery isolation. Easy to install, work perfectly, can sense a charging voltage from either battery and close the relay. Yours is a great choice. If you want to spend less, the Blue Sea 7610 is 1/2 the price, smaller, even easier to do a basic install and will meet all but the most extreme challenges you will throw at it.

One last thing that in my view is a critical part of a truck/solar/dual battery system is a smart shore charger. They can keep all your batteries in top condition full time even if you are not using the truck. It can markedly extend the life of your batteries. I've had good experience with BatteryMinders but there are several other brands that have equally good reputations.

 

[Dust999]

Everything else being equal, having more amp*hours capacity is better.

Which is more important--amp hours spec or the RC spec. i.e., The rolls battery has 115 and 115 vs the northstar at 59 vs 115. Which one is better for longer power delivery?

 

[Dust999]

Rolls is the best if you can afford it. Lifeline did not make your list, it should be considered. You want Deep Cycle. Period. Not marine or dual purpose or thin plate AGM marketing crap. Deep Cycle.
As far as amp/hrs the more the better. Better quality high amp/hr batteries are heavy. beware any lead acid battery claiming high numbers with low weight.
Excess solar is better, you will always get stretches of poor sun.A large panel is generally less expensive than two smaller panels of equal wattage. Large high voltage panels are even cheaper (ie 48v) and will allow smaller wiring but will require an MPPT controller which you would not need for 18v panels. More important for a full time rig over 500watts. A high quality charge controller installed close to the battery bank is important. You can't go wrong with Morningstar.

I have morningstar on my list as well as a steca controller. (Solarix MPPT 2010 or the PR2020)

 

[calicamper]

Just asking why a $300 battery manager? Im just wondering given the logic these units use is all the same, the build quality is all from the same makers in china. Rough roads Id rather replace a $27 controller due to rattled loose innards vs $300 unit that suffers the same result.

 

[Dust999]

Just asking why a $300 battery manager? Im just wondering given the logic these units use is all the same, the build quality is all from the same makers in china. Rough roads Id rather replace a $27 controller due to rattled loose innards vs $300 unit that suffers the same result.

I like the LCD readout on the steca ($140)

But, point taken.

 

[Joe917]

Just asking why a $300 battery manager? Im just wondering given the logic these units use is all the same, the build quality is all from the same makers in china. Rough roads Id rather replace a $27 controller due to rattled loose innards vs $300 unit that suffers the same result.

Why spend money on a charge controller? Because that $27 made in China won't be the only thing you have to replace after you let it loose on your battery bank. Chinese build quality is a function of the build specification, usually something specified by Walmart to be as cheap as possible. No wonder its mostly rubbish. Do your research, invest in quality, do it once.
While we're at it you are missing the most important part of the system : a battery monitor. Not a voltmeter, they are useless for SOC in a working system. You need to add a true amp/hr counting monitor to know what your system is actually doing. Trimetric or equivalent.

 

[calicamper]

When they fail your battery simply doesnt get managed. With dirt road use they will all fail in the same manner as in scrambled innards broken board etc. None of them are built special to handle dirt road vibrations. Just keep that in mind. As for functions they all operate the same way given the charge management process for a 12volt battery is pretty much written in stone already.

I'm simply just pointing out that in our use case price doesn't really translate to performance regarding durability. I like the displays too, the one I picked up toggles between, charge voltage, amp then battery status, charge mode, load if your pulling through the unit, and you can adjust the battery voltage protection levels if you want a custom protection level. Standard typically is 14 volts the units cut the float trickle charge to avoid cooking the battery and most have a load kill switch at 11volts to avoid killing the battery etc. That and unless your settong up a solar farm to light the whole camp were not running big power.