Adding an Auxiliary Battery

[akrvbob]

4 gage 12 volt wires?  The voltage has nothing to do in this usage.  A 4 G wire will handle up to 600V. 4G is large, and passes the power without excess resistance.

I want to tell him the minimum amount. You used the word stranded which needs to be explained to him. If he goes in and say I want a 4 gauge, 12 volt wire, they'll give him stranded wire. He'll get what he needs and it's one less thing he needs to learn.

One of the most most fundamental beliefs of this forum is to Simplify. But for some reason when it comes to electrical we insist on complicating things to the ultimate degree--potentially overwhelming the newcomers. We seen to think they have to learn everything (and all of it's possible complications) RIGHT NOW.

I'm much more of line-upon-line, layer-by-layer--that's how I did it.

We just think differently and maybe I'm wrong.
Bob

 

[bgq007]

To determine the actual power consumption of your MacBook (or anything you plan to run using AC power), I suggest that you get a Kill-a-Watt meter.  Do a search on this forum; there are plenty of posts about them.

Concerning the battery, what you'll want to look at in terms of capacity is the 20-hour rate.  Don't get a battery until you have at least some idea of your loads.  If you will have both  AC and DC loads, the easiest way to keep consistent is to convert all your loads to Watts and Watt*hours.  The battery to which you linked would have a capacity of 912 Watt*hours (12V * 76 Amp*hours).  For a learner AGM battery (which you'll likely end up murdering prematurely), you might want to look at one of the foreign-made brands such as Universal.  That way, when it dies early, you're not out as much cash.

Absorption refrigerators (the kind that can run on either propane or electricity) are not well-suited for battery power.  The way they operate is that they have a heating element, and creating heat by using electricity is very inefficient.  There are quite a few high-efficiency compressor refrigerators that have been discussed on this forum.  I'm sure that folks here with experience using them would be happy to share their insights.

So, are you saying that the battery I mentioned is capable of putting out 912 watts every hour for 20 hours (or 76 amps every hour for 20 hours)? Before the battery is dead? And by dead I mean I "murdered" it and no way to bring it back even by charging? Thus the idea that a solar solution is probably needed to be installed at the same time?

I have been searching online to better understand how these systems work. Its slow learning for me.

One question, if I am parked at a place that has shore power, could I plug in a surge protector (using adapters) to merely power/charge my laptop? Without risking the battery on my laptop?

 

[GotSmart]

I want to tell him the minimum amount. You used the word stranded which needs to be explained to him. If he goes in and say I want a 4 gauge, 12 volt wire, they'll give him stranded wire. He'll get what he needs and it's one less thing he needs to learn.

One of the most most fundamental beliefs of this forum is to Simplify. But for some reason when it comes to electrical we insist on complicating things to the ultimate degree--potentially overwhelming the newcomers. We seen to think they have to learn everything (and all of it's possible complications) RIGHT NOW.

I'm much more of line-upon-line, layer-by-layer--that's how I did it.  

We just think differently and maybe I'm wrong.
Bob

That answer is perfect.  

Electricity is scary, but taken one simple thing at a time extremely easy.  

After 40+ years I take some knowledge for granted.  

Other times I ask Sternwake. :s

 

[bgq007]

I want to tell him the minimum amount. You used the word stranded which needs to be explained to him. If he goes in and say I want a 4 gauge, 12 volt wire, they'll give him stranded wire. He'll get what he needs and it's one less thing he needs to learn.

One of the most most fundamental beliefs of this forum is to Simplify. But for some reason when it comes to electrical we insist on complicating things to the ultimate degree--potentially overwhelming the newcomers. We seen to think they have to learn everything (and all of it's possible complications) RIGHT NOW.

I'm much more of line-upon-line, layer-by-layer--that's how I did it.  

We just think differently and maybe I'm wrong.
Bob

Bob,

No, you aren't wrong. I was overwhelmed and confused before I even posted here. I wish I could say that has gone away, but it hasn't. At the same time, it is important for me to express my appreciation and to say that I am learning. Even if I am confused about things, I am still learning. 

I just asked a question about using shore power to charge my laptop. As I sit back and really think about what I NEED (right now) compared to what I might WANT for the future (since I am broke and unemployed looking for a way to make some under the table cash while I keep my fingers crossed for a Computer Forensics job), I have learned that my biggest desire is to be able to run and keep my laptop charged (along with my cell phone and any other small devices). 

That is what I need, so maybe I am parking at a place that I can plug into power (although I probably can't afford the camp fees). Or maybe I figure out some other alternative for the time being. I really don't know, but I am learning about things.

At the same time, I do believe people have been talking over my head. My hope in my OP was that I was going to tell people what I wanted and someone was going to give me a shopping list! LOL... Unrealistic, I know. But that is my level of understanding (and being comfortable in the understanding). 

Thanks!

Billy

 

[GotSmart]

Bob,

No, you aren't wrong. I was overwhelmed and confused before I even posted here. I wish I could say that has gone away, but it hasn't. At the same time, it is important for me to express my appreciation and to say that I am learning. Even if I am confused about things, I am still learning. 

I just asked a question about using shore power to charge my laptop. As I sit back and really think about what I NEED (right now) compared to what I might WANT for the future (since I am broke and unemployed looking for a way to make some under the table cash while I keep my fingers crossed for a Computer Forensics job), I have learned that my biggest desire is to be able to run and keep my laptop charged (along with my cell phone and any other small devices). 

That is what I need, so maybe I am parking at a place that I can plug into power (although I probably can't afford the camp fees). Or maybe I figure out some other alternative for the time being. I really don't know, but I am learning about things.

At the same time, I do believe people have been talking over my head. My hope in my OP was that I was going to tell people what I wanted and someone was going to give me a shopping list! LOL... Unrealistic, I know. But that is my level of understanding (and being comfortable in the understanding). 

Thanks!

Billy

You were given several shopping lists, but right now you do not need a list, but an immediate solution.

McDonalds, Laundromat, library.  They always worked for me for emergency charging.  

For long term use, there are a number of solar kits you can get that are not expensive that will do the immediate job.  

$60 for a folding panel that will do your small electronics.

If you have a battery, from $270.  Suitcase. (all in one w battery) about $500

For a full time large power solution expect to spend about $800 to 1K.  This is for van size. Parts battery and panels wires

 

[AuricTech]

So, are you saying that the battery I mentioned is capable of putting out 912 watts every hour for 20 hours (or 76 amps every hour for 20 hours)? Before the battery is dead? And by dead I mean I "murdered" it and no way to bring it back even by charging? Thus the idea that a solar solution is probably needed to be installed at the same time?

I have been searching online to better understand how these systems work. Its slow learning for me.

One question, if I am parked at a place that has shore power, could I plug in a surge protector (using adapters) to merely power/charge my laptop? Without risking the battery on my laptop?

No, it can put out a total of 912 Watt*hours (or 76 Amp*hours) before it's deader than Elvis.  Ideally, you'll refrain from drawing more than 50% of that before recharging.  Even a 50% drawdown is something to avoid on a routine basis; 25% is better.

So, if your MacBook's average power use is 50 Watts (the rate at which it uses power), you could run it off this battery for about 4.5 hours to a 25% depth of discharge, or about 9 hours for a 50% depth of discharge (50 Watts * 4.5 hours = 225 Watt*hours).

Of course, since you'll need an inverter to power the MacBook's power brick, you'll need to figure in conversion losses.  That will depend on the inverter in question.

Shore power is standard utility power, so I can't see any problems running your laptop from it.

 

[akrvbob]

This really is the very simplist answer you can get:
[font=Verdana, Arial, sans-serif]Okay, here it is in one simple sentence that will meet all your requirements. [/font]

[font=Verdana, Arial, sans-serif]Buy two 4 gauge, 12 volt wires, and a basic On-Off Switch made for batteries and wire them from your starting battery, to the on-off switch, to the house battery. As was pointed out, you also must run a 4 gauge wire back from the negative post of the house battery back to the negative post of the starting battery.  [/font]

[font=Verdana, Arial, sans-serif]It should cost $50 and will charge your battery off the alternator and anyone can do it--no wiring required except 6 simple bolts (2 on the batteries and 2 on the back of the "on-Off" switch and one each on the negative posts of the batteries. The hardest part will be drilling the hole to get the wire into the van. I'd put the battery on the floorboard of the passenger seat so the wire is close[/font]

[font=Verdana, Arial, sans-serif]It's not automatic--you have to remember to turn it on and off. To get automatic you need a continuous duty solenoid, but that will require some wiring, not much, but some.[/font]

[font=Verdana, Arial, sans-serif]If you have leftover money, get a Renogy 100 watt solar kit and mount it to the roof--some wiring required. Or a 100 watt Renogy suitcase solar kit--virtually no wiring required.[/font]

[font=Verdana, Arial, sans-serif]Buy the biggest Walmart marine battery you can find--be sure to save the receipt. It's a learning battery and you are probably going to kill it--that's normal, most of us do that! Chances are you'll kill it while it's under warranty so you can exchange it.[/font]

[font=Verdana, Arial, sans-serif]Don't let the complexity paralyze you, start simple and small and learn as you go. Expect to make some mistakes, just try not to lose too much money making them.[/font]

[font=Verdana, Arial, sans-serif]A Nearly Totally Free Solution That's Super Easy:[/font]

[font=Verdana, Arial, sans-serif]Get a standard daypack/bookbag and a standard powerstrip. Put the powerstrip in the bottom of the daypack and plug all your electrical devices into the bag and plug them into the powerstrip. Run the cord from the powerstrip through a very discrete hole in the bottom of the bag.[/font]

[font=Verdana, Arial, sans-serif]Go to McDonalds, the library, bookstore, a cafe--anywhere you can plug in. Sit the book bag down on the floor beside you and plug the powerstrip in and you are now charging all your devices and no one knows it. Stay there for as long as you can and hopefully all your devices will be charged.[/font]

[font=Verdana, Arial, sans-serif]If you can afford it, get a battery pack with the USB ports and charge it too. It will recharge your phone multiple times away from the power source.[/font]

[font=Verdana, Arial, sans-serif]Bob[/font]

 

[bgq007]

No, it can put out a total of 912 Watt*hours (or 76 Amp*hours) before it's deader than Elvis.  Ideally, you'll refrain from drawing more than 50% of that before recharging.  Even a 50% drawdown is something to avoid on a routine basis; 25% is better.

So, if your MacBook's average power use is 50 Watts (the rate at which it uses power), you could run it off this battery for about 4.5 hours to a 25% depth of discharge, or about 9 hours for a 50% depth of discharge (50 Watts * 4.5 hours = 225 Watt*hours).

Of course, since you'll need an inverter to power the MacBook's power brick, you'll need to figure in conversion losses.  That will depend on the inverter in question.

Shore power is standard utility power, so I can't see any problems running your laptop from it.

Thank you! This all makes sense to me. Realistically I could consider the battery I mentioned and a solar panel like this (http://portland.craigslist.org/mlt/rvd/5081053790.html) and a charge controller (not sure which one) and just run a system separate from my starter battery to power my laptop when I want. Then if I ever needed to jump my battery, couldn't I just set the AGM next to my engine and put jumper cables on both batteries and crank it? 

This would put me in a place where I get what I need now, but flexible for modification in the future. HMMM.....

 

[bgq007]

This really is the very simplist answer you can get:
[font=Verdana, Arial, sans-serif]Okay, here it is in one simple sentence that will meet all your requirements. [/font]

[font=Verdana, Arial, sans-serif]Buy two 4 gauge, 12 volt wires, and a basic On-Off Switch made for batteries and wire them from your starting battery, to the on-off switch, to the house battery. As was pointed out, you also must run a 4 gauge wire back from the negative post of the house battery back to the negative post of the starting battery.  [/font]

[font=Verdana, Arial, sans-serif]It should cost $50 and will charge your battery off the alternator and anyone can do it--no wiring required except 6 simple bolts (2 on the batteries and 2 on the back of the "on-Off" switch and one each on the negative posts of the batteries. The hardest part will be drilling the hole to get the wire into the van. I'd put the battery on the floorboard of the passenger seat so the wire is close[/font]

[font=Verdana, Arial, sans-serif]It's not automatic--you have to remember to turn it on and off. To get automatic you need a continuous duty solenoid, but that will require some wiring, not much, but some.[/font]

[font=Verdana, Arial, sans-serif]If you have leftover money, get a Renogy 100 watt solar kit and mount it to the roof--some wiring required. Or a 100 watt Renogy suitcase solar kit--virtually no wiring required.[/font]

[font=Verdana, Arial, sans-serif]Buy the biggest Walmart marine battery you can find--be sure to save the receipt. It's a learning battery and you are probably going to kill it--that's normal, most of us do that! Chances are you'll kill it while it's under warranty so you can exchange it.[/font]

[font=Verdana, Arial, sans-serif]Don't let the complexity paralyze you, start simple and small and learn as you go. Expect to make some mistakes, just try not to lose too much money making them.[/font]

[font=Verdana, Arial, sans-serif]A Nearly Totally Free Solution That's Super Easy:[/font]

[font=Verdana, Arial, sans-serif]Get a standard daypack/bookbag and a standard powerstrip. Put the powerstrip in the bottom of the daypack and plug all your electrical devices into the bag and plug them into the powerstrip. Run the cord from the powerstrip through a very discrete hole in the bottom of the bag.[/font]

[font=Verdana, Arial, sans-serif]Go to McDonalds, the library, bookstore, a cafe--anywhere you can plug in. Sit the book bag down on the floor beside you and plug the powerstrip in and you are now charging all your devices and no one knows it. Stay there for as long as you can and hopefully all your devices will be charged.[/font]

[font=Verdana, Arial, sans-serif]If you can afford it, get a battery pack with the USB ports and charge it too. It will recharge your phone multiple times away from the power source.[/font]

[font=Verdana, Arial, sans-serif]Bob[/font]

Bob,

Thanks. I am warming up to the manual switch idea. I am sort of considering a separate house system and forgetting about tying it in to the main battery at this moment. Just going solar and a battery. 

The powerstrip idea is a good one, and if I found myself in a town then I think this would make sense. The scenario was about "boondocking" if I understand the term correctly. 

Billy

 

[GotSmart]

Due to the fact that clean potable water is critical, you must come to town fairly often. That is when you can charge your items.

 

[SternWake]

Due to the fact that clean potable water is critical, you must come to town fairly often.  That is when you can charge your items.

The Manual switch method is a good one, but it is not for everybody.

One can definitely forgo hooking the Aux battery to the alternator.

however the Alternator is a very capable charging source that can recharge a battery upto 80% quickly if it has thick cabling run to it.  All batteries limit how much current they can accept  in this state of charge range, and there is no way to safely speed it up.

Once you rig up a solar system, you will have more confidence in running wires, and can add an alternator charging circuit later, for when the sun does not shine.

 

[akrvbob]

If you are thinking of mainly boondocking and not driving much, solar is by far the best idea.

If you are thinking solar and want things to be as simple as possible, and get really good bang for your buck, then you want to get a Renogy kit. Decide how much you can spend and buy the kit that fits that budget. We'll help you decide which kit and then hel you install it by answering questions.

It's true you can build your own system by buying the parts separately. You can buy better components and pay less per watt for the panel. BUT, there is a steep learning curve--is that what you want? If it is we will be glad to make recommendations for controller, panel, batteries, cables and fuses. And shipping may eliminate the savings unless you are near solar stores.

Renogy kits have very little learning curve and are very good bang for your buck and good decent equipment. For most people, they are by far your best choice. From what you've told us about you, that's what I would recommend to you.

A 100 watt kit from Amazon will meet your simple needs, cost about $200 and probably be within your abilities to install. If not then the suitcase kit will be more money, but be super simple to install.

Bob

 

[bgq007]

If you are thinking of mainly boondocking and not driving much, solar is by far the best idea.

If you are thinking solar and want things to be as simple as possible, and get really good bang for your buck, then you want to get a Renogy kit. Decide how much you can spend and buy the kit that fits that budget. We'll help you decide which kit and then hel you install it by answering questions.

It's true you can build your own system by buying the parts separately. You can buy better components and pay less per watt for the panel. BUT, there is a steep learning curve--is that what you want? If it is we will be glad to make recommendations for controller, panel, batteries, cables and fuses. And shipping may eliminate the savings unless you are near solar stores.

Renogy kits have very little learning curve and are very good bang for your buck and good decent equipment.  For most people, they are by far your best choice. From what you've told us about you, that's what I would recommend to you.

A 100 watt kit from Amazon will meet your simple needs, cost about $200 and probably be within your abilities to install. If not then the suitcase kit will be more money, but be super simple to install.

Bob

I think getting something that has a good reputation and that is a solid product makes sense. The fear I have from the link I shared is that I am not sure how well the seller stands behind the product. On a couple of occasions I have looked at Renogy. My issue is really getting something for the least amount of money that meets my needs. 

Like I said, to start, I really just need to power my laptop. Because it is a MacBook, there is no DC adapter so I will need to use an inverter. The AC brick says it is 85W. I posted the other details in a different post. I realize that it would make sense to actually measure the volts but I don't have a meter. 

The battery is going to need to be sealed and safe to have inside the van. So it really becomes what can I get that will charge a battery (12v) relatively quick. 

But maybe it might be easier to do this... Bob... Let's say (hypothetically) I am giving YOU $600 to spend on everything you need to add solar to a van. What would you buy? Remember, you only have $600 to buy EVERYTHING (literally, nothing can be extra). What is this system and how is it going to operate? How fast will it charge? How will it charge my laptop? How many times can I charge? Etc. Oh and of course I will have other odds and ends that need charging, but nothing bigger than a laptop unless I can find a small fridge cheap.

Billy

PS - I live in Oregon, get great sun in the spring/summer but crappy after mid-September. We have no sales tax.

 

[GotSmart]

I will show you what Renogy has.  You go through their website, and free shipping and no OR tax.

If you want a system that you can plug and play I would recommend a suitcase.  25 year power warranty on this.

http://www.renogy-store.com/Renogy-100W-12V-Mono-Portable-Solar-Suitcase-p/kit-stcs100d.htm

That has 100w of power and a controller.  It has clips to go on the battery. $279.00

Amazon has some decent inverters for less than $100 if all you are going to use is small equipment. The ones Renogy has are a lot more expensive.  

http://www.amazon.com/s/ref=nb_sb_noss_1?url=search-alias=aps&field-keywords=inverter

Now all you need is to find a decent battery in your location. Again the Renogy ones are high dollar. 

The alternative is to get components and build a custom setup.  That requires a lot of details..........

 

[bgq007]

I will show you what Renogy has.  You go through their website, and free shipping and no OR tax.

If you want a system that you can plug and play I would recommend a suitcase.  25 year power warranty on this.

http://www.renogy-store.com/Renogy-100W-12V-Mono-Portable-Solar-Suitcase-p/kit-stcs100d.htm

That has 100w of power and a controller.  It has clips to go on the battery. $279.00

Amazon has some decent inverters for less than $100 if all you are going to use is small equipment. The ones Renogy has are a lot more expensive.  

http://www.amazon.com/s/ref=nb_sb_noss_1?url=search-alias=aps&field-keywords=inverter

Now all you need is to find a decent battery in your location. Again the Renogy ones are high dollar. 

The alternative is to get components and build a custom setup.  That requires a lot of details..........

GotSmart,

That kit looks good. I was thinking of just getting a large panel because I have a Packasport box and it is so large that I could mount the panel to the top of it. Might make it too heavy to lift though....

 

[akrvbob]

I'd buy this 200 watt kit and and a 12 volt agm battery:
http://www.amazon.com/RENOGY®-Solar-Bundle-200W-Monocrystalline/dp/B00ZYURFK4/

The kit is $355 and that leaves you $200 for the battery and $50 for a cushion.

200 watts is plenty for most people and probably too much for you. But you can run LED lights, a fan and even a 12 volt compressor fridge if you can ever afford it.
Bob

 

[bgq007]

I'd buy this 200 watt kit and and a 12 volt agm battery:
http://www.amazon.com/RENOGY®-Solar-Bundle-200W-Monocrystalline/dp/B00ZYURFK4/

The kit is $355 and that leaves you $200 for the battery and $50 for a cushion.

200 watts is plenty for most people and probably too much for you. But you can run LED lights, a fan and even a 12 volt compressor fridge if you can ever afford it.
Bob

Thanks Bob... Does the controller on that package have the ability to modify the voltage so that it will be acceptable for the AGM battery? I didn't see anything in the description.

Also, I am not sure how I would mount 2 panels on my roof.... Would 1 panel be enough power to start and then I could save the other panel until I can figure out a mounting system?

Billy

 

[akrvbob]

Just buy a 100 watt kit and save yourself some money. You can always buy a second kit later or a suitcase system that doesn't go on the roof.

You don't have the money to get a high end controller, it will be a minimum of $200 by itself and probably much more. Better to spend the money on an extra solar panels so your batteries are always kept full and happy. Batteries that stay at 75% or above all the time and most of their time at 100% are happy batteries. An extra panel can easily do that but few chargers really give you the perfect charging style for AGM.

AGM batteries only want higher voltages during bulk charging. By having too much solar, they rarely are in the bulk charging phase so they don't need a charger that gives very high charge rates.

Don't let perfection be the mortal enemy of very good.
Bob

 

[Optimistic Paranoid]

Like I said, to start, I really just need to power my laptop. Because it is a MacBook, there is no DC adapter so I will need to use an inverter. The AC brick says it is 85W. I posted the other details in a different post. I realize that it would make sense to actually measure the volts but I don't have a meter. 

As you probably know, there are two kinds of inverters.  Pure Sine Wave inverters and Modified Sine Wave inverters.  Pure Sine Wave inverters (called True Sine Wave by some manufacturers) put out exactly the same kind of power that the public utilities put out.  Modified Sine Wave inverters put out a square wave that's been modified a bit to make it semi-similar to a true sine wave.

Inexpensive inverters are always MSW.  PSW is a lot more expensive.  MOST things run more or less ok on MSW, but a few don't.  As an example, I've read that some brands of cordless power tools recharge just fine on MSW, but some brands won't recharge at all unless they get a PSW.  Some things run, but run slower.  Microwave Ovens take longer to cook on MSW than they do on PSW. Some kinds of electronics are actually damaged by MSW.

I'm not a Mac guy, I have no idea if a Mac will work off an MSW or not.  I suggest you research this before you buy.  Don't know if anyone here would know or not.  Your best bet is probably to get out on a Mac forum and ask questions.  If you do find people that are successfully using an MSW inverter to power a Mac, ask them what BRAND they are using as well as how much power they are.

Regards
John

 

[GotSmart]

GotSmart,

That kit looks good. I was thinking of just getting a large panel because I have a Packasport box and it is so large that I could mount the panel to the top of it. Might make it too heavy to lift though....

You would be asking for trouble mounting a panel to that box.  The box is not designed for that. To do that you would need a flex panel.  Use the KISS method and do it simple.  Once you have a job and money you can upgrade and sell the unneeded parts on CL.  They keep value.