Battery type question

[SoulRaven]

Battery type question

I have been thinking of ways (solar, small gas generator) to charge a house battery and have come full circle to the keep it simple approach.

My thoughts are now to use the trucks alternator to charge a house battery with just a simple $20 disconnect switch.

I plan on using a group 24 in a plastic box with a circuit breaker right off the starting battery and a six-circuit fuse box off the house battery.

So the question is should I go marine starting/deep cycle or pure deep cycle?

 

[gadgetMe]

Charging house battery with the alternator ( no problem )

A pure deep cycle battery will last much longer, But the marine/start battery will work for quite a while also.

The longest lasting battery is the AGM sealed battery, trouble is they cost triple the money

Gadget

 

[SoulRaven]

To fine tune the question I will be on the move every 3-4 days.

In the meantime if I have to start the truck I want a battery that will charge up quickly conserving as much fuel as possible.

 

[Zil]

The problem with the AGM deep cycle battery is it requires special charging parameters or it would last long compared to cost. But they don't require venting or water checks. A pair of 6 volt golf cart batteries are the least costly way to have a reliable house bank. After you teach your self about battery management graduate to the expensive AGM. My personal recommendation is to skip the marine version batteries. You will eventually want a better charging source than the truck alternator. But if doing that run heaver wires from the alternator to the house bank.

 

[SternWake]

Good luck in even finding a true deep cycle group 24 battery. Most are either just starting batteries or dual purpose marine batteries.

Likely you would not benefit from a true deep cycle anyway as yours is s prescription for chronic undercharging and premature battery death. A true deep cycle might handle chronic undercharging better than a marine battery but is still damaged by it.

While the alternator, if wired to the house battery through fat cabling, can recharge a battery fairly quickly to 80% State of charge, that last 20% takes hours and hours, no matter what 'magical' charging source you use. No matter what some chargers or some people claim, that last 20% takes hours.

Getting that last 20% into the battery is paramount for battery longevity.

Getting that battery back upto 80% quickly, when driving should be your goal, and resign yourself to replacing the battery more often that you currently plan.

The alternator's energy generation is not free. Every 25 amps the alternator produces requires 1 engine HP. So trying to save gas by buying a battery which in theory can be recharged faster, like an AGM, will likely not be measurable, and certainly not without tools costing in excess of several batteries.

 

[akrvbob]

I agree with Sternwake. Chances are very good that this is going to be learning battery and it will die a premature death. No problem with that, I think most of us did the exact same thing. But don't spend a lot of money on a learning battery! I'd suggest a Walmart group 27 Marine and plan on replacing it in a year or two. The last Walmart battery I had came with a great warranty and when it died early they just gave me a new one. KEEP THE RECIEPT!
Bob

 

[SoulRaven]

I think I am going to go with a single Wall mart marine battery hooked to a controller and a 7 watt solar panel with a 25 foot extension cord.

My truck has a fairly new starter that does not draw a bunch of amps.

With east coast boondocking there always is a tree for shade. When it’s cold you just move into full sun.

Over the winter in Florida the ideal parking spot will get morning sun until about 10am then shade until nightfall for a reptilian like existence.

Would there be any issues if I bought two of the 7 watt $22 panels mounted both of them side by side to a piece of plywood then mounted both to an adjustable Harbor Freight bracket?

Could I take just one 7W panel and mount Reflectix to 1/8 hardboard in a solar oven like fashion to increase output?

I do keep receipts with the truck.

I am on my second free lifetime muffler!

 

[SternWake]

You are vastly overestimating the ability of a 7 watt solar panel to do any meaningful recharging.

Such a panel is designed to be a float charger. Designed to counteract the draw of engine computer memory, door locks, ect. One many newer vehicles, 7 watts would not be enough for this task.

As for returning anything into a cycled battery with a 7 watt panel, you are kidding yourself. It would take days to return what a laptop could remove in an hour. Especially if you plan on using a long extension cord.

Even with a reflectix concentrator. Most panels will say to NOT concentrate light on the panel. The extra heating would likely negate any increase anyway.

While a failing engine starter does draw more amps than a new one, it is hardly a meaningful statistic as far as your battery is concerned. The new starter will pull 245 amps instead of 265 for that 3 seconds. Big freaking whoop.

Plan on getting more solar, and plan on using fat wiring from alternator through your Disconnect switch to the Aux battery. At least 4awg , Fused at both ends or triply make sure no chafing of the wire can occur. The switch should be rated for at least 100 amps. The battery should be grounded to the frame with 4awg, or grounded to the starter battery(-) with 4awg, or grounded to the engine, with 4awg.


With 45 watts and 4awg cable from alternator to Aux battery, you will do fine with your listed draws.

With 14 watts, 18 awg and a 20 amp switch, you might have a burned out truck carcass, and/or will be asking for rides to walmart often in an attempt to get another battery.

Meeting your electrical demands is not where you should be trying to save money. Being cheap here, will wind up costing you more, and you will regret every penny pinched.

 

[SoulRaven]

So in conclusion I need a minimum of a 50-watt panel w/controller with a 35ahr deep cycle separate from the trucks electrical system.

---

Would you recommend this kit with a 35 ahr deep cycle?

http://www.amazon.com/Solar-Panel-Starter-100W-Monocrystalline/dp/B00BFCNFRM/ref=pd_cp_hi_3

 

[SternWake]

I'd say get a bigger aux battery. Remember only half the battery capacity is useable. Using more than 50% seriously shortens the life of the battery.

If you are vigilant about monitoring battery voltage, you can hook the solar to a battery without a controller, but it is better to get a controller and not worry about frying the battery. Small PWM controllers are not expensive.

Wiring the Aux battery to receive alternator amps might overwhelm the electrically unsavvy, but any and all charging sources should be taken advantage of. It is not really that difficult.

http://www.expeditionportal.com/for...ke-a-cheap-isolated-dual-battery-setup-for-50

And the alternator is very effective at bringing a battery upto 80% charged, if the cabling between alternator and battery is thick. With a sub 85 amp hour battery, 4 awg might be a bit overkill, unless the distance is more than 25 feet round trip.

Most solar newbies act like the panel's rating is met anytime there is sunlight, when the rating is almost never achieved, as ratings are established under ideal conditions in a lab with a cool panel, not a baking panel with too thin wiring. Generally around noon 90 minutes before and after, 85% of the panels rating will make it into the batteries.
It is very hard to oversize a solar and battery system. Few individuals on this planet have installed solar and then said, wait, I bought way too much.

Far too many that thought x amount was all they needed, found out that it was not, and then had to add more to meet their needs which requires more than just another panel. Usually the wiring, mounting system and controller need to be updated as well, and the abused battery replaced prematurely too.

Costing more in the long run vs doing it right the first time.

---

My 130 watt framed Kyocera panel, in 2007, cost 710$ before shipping, and I spent another 450$ on the Blue sky 2512i MPPT charge controller and IPN pro remote battery monitor.

In 2012 I added a Non framed unisolar 68 watt to the other side of my roof for 230$

When I see the prices on Solar kits available today.............

 

[akrvbob]

Mr.LooRead, I've heard lots of good things about that solar kit and I think you would be well served by it.

With that kit you want an even bigger, better battery. A Walmart group 29 marine would be good. It'll only be another $20 or so.

In case you're wondering, no problem following Sternwakes great advice on wiring the battery to the alternator and solar panels at the same time. Having both is a great idea and they compliment each other very well!

With that kit you can easily build a little stand and hook it up with an extension cord so you can have it out in the sun and the van in the shade. I have a friend who bought two of those kits and hinged them together and sets them out in the sun.
Bob

 

[Starlight]

Mr. Loo --

My "simple" system has pretty much come down to -- a solar battery charger. I considered a larger battery system, thinking about keeping foods cold -- running fans -- using lap top --

I haven't set it up, yet, but I can attain my goals without a large setup, from a special solar charger I found on Bob's blog. Some solar battery chargers have 110v capacity for a fan, lap top charger -- and I can set up a food cooler with double insulation built around it -- and get good use out of a bag of ice.

I like simple. This was simple.

 

[TALLMAN]

Have a 36 ft Holiday Rambler, 96 any suggestions what would be the best batteries for boon docking, no solar at this time. What I have now seems to run down after about 4 hours, they are 5 years old. Couple small lights, and gas refrigator is all I have running. they go from about 12 to 7 in four hours, though am not sure what that measures. am new and learning, its a thing that I stick into the lighter.

 

[Mac J]

check out my post in .....how many watts is your solar set up.... It may answer some of your questions Mr LooReed.

 

[Lucky mike]

Have a 36 ft Holiday Rambler, 96 any suggestions what would be the best batteries for boon docking, no solar at this time. What I have now seems to run down after about 4 hours, they are 5 years old. Couple small lights, and gas refrigator is all I have running. they go from about 12 to 7 in four hours, though am not sure what that measures. am new and learning, its a thing that I stick into the lighter.

the odds are if the batteries are 5 yrs old its time for a fresh pair or at least rebuild those if its not in the budget..(youtube has a link for refreshing deep cycles)....the odds are the converter charger in your RV is not designed for more than 2 house batteries..you could save alot of power by changing lites to LED , even if its not all of them , just changing a few in key ligting areas make a big difference...the fridge running on gas does not pull enough power to draw the batteries down..if you are charging your batteries thru the generator it takes around 4 hours to charge them correctly so keep that in mind..also never run your batteries below 12 to 12.5 volts or you will damage them .....hence the reason there dropping off so fast..

 

[WheelEstate USA]

MrLoo...you can get the same kit from Renology on eBay for cheaper...
http://www.ebay.com/itm/100-Watt-So...692?pt=LH_DefaultDomain_0&hash=item3f298e4e6c

Renology has good panels. I've used and installed several of their kits.
I recommend them for a fair priced entry level kit that's expandable by adding another 100W panel as needed. The controller isn't fancy, but is durable.

 

[anm]

In case anyone's in the area, someone in Chandler, AZ is selling T105 batteries for $109.20 but you have to go there and get them.

They're available here:
http://www.ebay.com/itm/Lead-Acid-T...US_Rechargeable_Batteries&hash=item258ffa7866

If I was further along I'd drive out there and pick up a pair, it's only 421 miles...