The car battery discharged in backcountry, now what?

[JackSilb]

Here's a great way and inexpensive - solar!

http://www.icpsolar.com/4105/portabl...r_charging.asp (http://www.icpsolar.com/4105/portable_power_charging.asp)

I starting this Thread as a follow-up of the discussion on power packs. (http://www.4wdtrips.net/forum/showthread.php?t=3734)

OK, assuming you don't have a power pack and/or your power pack was not charged some some reason. For another reason, such as someone forgot to turn off radios and other gear, your truck battery is discharged in the morning. And you are alone, I guess you got the picture.

How one would use solar power to charge a battery?
a) Charge the truck main battery
b) Charge the power pack

What is the best way? a or b?

I would imagine we should disconnect the main battery from the truck so it can be charged. Can it really be charged after running low using a solar power unit as listed above?
Can we charge a power pack using solar power?

Lets talk.
-JACK

[JackSilb]

It seems that this unit (http://www.solarcharger.com/Sunsei-Solar-Charger-SE-1200-TEMPORARY-OUT-OF-STOCK?sc=2&category=62)can charge a battery



Model SE-1200
Power: 1200mA, 15V (18W)
Plug’n’Play® for quick connections, connect multiple panels in seconds without tools or rewiring
The box includes
1 solar panel SE-1200
+ 1 multi-purpose adapter set (cigarette lighter, female cigarette lighter, battery clamp, terminal ring connector and wire connector)
+ 1 extension wire connector
+ 1 set mounting screws
Important: for this powerful solar panel you’ll need a charge controller, please consult the related products section
Dimensions: 39.4” x 13.8” x 1.2” / 100.0 cm x 35.0 cm x 3.0 cm
Weight: 9.5 lbs / 4.3 kg
Weatherproof
10 year power warranty

[alanh]

Jack,

My two cents worth. The logic may be faulty, but at least I'm trying to apply logic!

Before deciding which to charge, the main battery or the power pack, I think I'd consider the size and state of discharge of each.

If the main battery was just a bit weak and the power pack is really dead, I'd try the main battery. Do the opposite if the battery condition is the other way.

I'm wondering if you should consider the relative size too. If both are equally "dead", maybe use the solar charger on the smaller battery. My theory being that it might take a lot more energy (and thus time) to get the bigger battery charged up to a usable state than the smaller one. One has to consider voltage. (I don't think a 3 volt battery will turn over the starter no matter how big it is.) The smaller battery would get up to a usable voltage quicker because the cells are smaller. There would be less energy there than a big battery at the same voltage though. But I still think the smaller one would win out because it would take less energy to get a high enough voltage and enough current capacity at the same time in the smaller battery. Its all dependent on battery chemistry too though. Its getting too complicated - time to let someone else take over.

[JackSilb]

Good points Alan.

Also, I believe it may take more than a day to have enough juice to start the engine.

In the case the main battery is really discharged, I would disconnect the main battery, start the truck on the battery pack then connect the main battery again once the engine is running.

Of course, if it is a stick shift an you happen to be close to a down hill, go for it.
-JACK

[MountainBiker]

At 18 watts, it is going to take a LONG time and a lot of sun to get either battery to a useful state. I would hike out before waiting for that thing to charge the battery.

[JackSilb]

Maybe,

Quick computation: 1.2 A x 20 hours (over two days) = 24 A.
It may be just the juice needed to add to the recovery power of your battery.
Assuming your battery can have a high current / rapid discharge capability, it can have a pick current to run the starter. That is more than 24A for a short period time.

I know I am getting out of my comfort zone on starters and batteries here.
I hope people can jump in the discussion.

-JACK

[MountainBiker]

The common scenario that I can foresee is a lamp or radio was left on, so you will have a nearly fully discharged battery. I don't know that 24 amps will get it to a state where it will start a cold engine, but that is an okay ballpark goal for most car batteries.

The key questions: are you in any shade at all? Are there any clouds? How many hours of sunlight do you have? From what I've seen on solar charger efficiency, they need nearly full sun to get close to their rating, and morning/afternoon sun will provide quite a bit less than the max rating. My point is, that to get 10 hours of full sun in a day will be difficult. And the charging is not 100% efficient.

I suppose there will be times when you are in the desert in summer, and full sun will be available. And if the battery wasn't fully discharged, but is just weak, then a solar charger might be useful.

IMO, a fully charged 2nd battery, or jumper cables and 2nd vehicle are much better usage of space and dollars than a solar charger for this purpose. Again, that is of course just my opinion, for most situations I can think of.

[JackSilb]

I agree that a second battery or a battery pack is better. I was wondering besides that, what can we do.

I see your point on the efficiency. That cut on the useful hours of a day to use.

Thanks
-JACK

[cruiser guy]

I'm a firm believer in the manual tranny! Less prone to breakdown and it can help you with a discharged battery as Jack has pointed out!

For folks like me with a diesel that REQUIRES two batteries for starting I think I'd be waiting a LONG time for a solar charge.

[JackSilb]

Charles, now that you mentioned that, I remember pushing my VW many times under 40C sunny and "cold" rainy days. Not cool to ask your girlfriend to give you a hand. I guess I survived.

-JACK

[cruiser guy]

See, I've rescued one guy in the past year with a burned out automatic tranny and there have been 2-3 others with similar problems over that time. My cousin has been left on the road when his auto tranny lost a gear yet I have driven my truck from Mazatlan, Mexico to Vancouver, Canada once when a small part ($20) in the shifter broke and I did it all in only 3rd and 4th!
Enough hijack on the bad battery in the backcountry thread!

[HenryJ]

I agree that a second battery or a battery pack is better. I was wondering besides that, what can we do...From time to time I carry a small two cycle generator. It has a battery charger and I have a quick connector to attach to the truck. It has been my thought that in a pinch I could actually operate the truck on the voltage provided by the generator.

Mine is a Coleman UltiMite 1100w generator made by Robin for Subaru. It is in a tube steel cage that measures 12" x 12" x 12" and weighs 25 lbs.
As best I can find these discontinued generators were part of a Subaru promotion (http://www.irvinesubaru.com/interests/generator.html). The UltiMite Portable Generator (item No. SOA926U100) sells for a suggested retail price of $595 and is available from Irvine Subaru parts department.You may be able to contact Frank Irvine Subaru (desi@irvinesubaru.com) for one. There are stories of magnets failing and I am not sure I would spend $595 on a discontinued generator. 15. What generator do you recommend?

We have not used a generator ourselves so can't recommend any specific unit, but here are several that have sufficient output and are small enough to carry in your aircraft:

Honda's 1000 watt portable unit weighs only 29 lbs, 18"L x 9"W x 15"H www.hondapowerequipment.com/genligframe.htm

The Coleman UltiMite 1100 watt unit weighs only 25 lbs, www.ultimite.com/welcome.htm

The Generac Model 1532-0 G1000M
www.generac-portables.com/products/generators/generator.cfm?ID=181

Yamaha EF1000 www.yamaha-motor.com/01gen/premium_frame.html

Arctic Cat www.arctic-cat.com/generators/AC750GD.asp

This info is provided as a service for our customers. We have no relationship with any of the above companies. Be sure the generator you choose has 12 volts too. All you need to do is add some quick connectors so that you can attach the generator and warm the batteries with a quick charge. I set up quick connectors front and rear for the winch. I made a short adapter cable to attach the generator. I also set up my jumper cables for this attachment-

http://www.s-10crewcab.com/coppermine/albums/userpics/10006/boosterc.jpg

I do have a small solar panel for charging AA batteries and use it to maintain the battery in the boat. It is a small trickle charge. It will charge a couple AA batteries in a day to a usable charge, but I would not want to have to rely on it every time.
I think the generator is a better idea for an emergency power supply in the event of battery failures. I do pack a jump start battery pack as well for my remote power needs and as an emergency back-up. The generator could charge either.

[David A. Wright]

How one would use solar power to charge a battery?
a) Charge the truck main battery
b) Charge the power pack

What is the best way? a or b?

1.) My truck has a manual transmission, so it's possible to start by rolling down an incline or push starting it.

2.) If I couldn't roll it to a start, then I'd (a.) charge the truck battery. My Instant Power takes at least two full days to charge to full capacity, I'm sure I could get the truck battery to turn over the starter far quicker.

[MountainBiker]

1.) My truck has a manual transmission, so it's possible to start by rolling down an incline or push starting it.
Yeah? Is that possible with fuel injection and a fully dead battery? I haven't tried it on a modern vehicle.

[cruiser guy]

Yeah? Is that possible with fuel injection and a fully dead battery? I haven't tried it on a modern vehicle.

Maybe not with a FULLY dead battery but most batteries "bounce back" a little after you take off the load.
Fortunately my vehicle doesn't have a computer, electric fuel pump or any of those "goodies" than require a battery. It follows the KISS principle and that's fine with me.

[David A. Wright]

Yeah? Is that possible with fuel injection and a fully dead battery? I haven't tried it on a modern vehicle.
I really don't have an answer for that question regarding a FULLY dead battery (such as one in which one or more cells shorted out). I'm sure each vehicle is unique in how it will handle a dead battery.

However, if the battery was drained by leaving on lights, etcetera, there's still residual charge left; just not enough to turn over the starter and engine. There might be enough juice left to trigger the fuel injector(s) and a spark plug or two. If gas and spark occure, then the engine should fire.

Rolling down a hill long enough should also start the alternator pumping some juice into the power system, which would also aid the process to get the engine running again, even if none of the voltage/amperage is being stored into the battery.

[Montara Ranger]

I know this is an old thread, but I found this while researching battery chargers. This may be a good solution for preventing a dead battery. Having a single battery set up I may just have to pry the wallet open and get one. The device is the Battery Brain. http://www.secondchancegarage.com/public/676.cfm (http://www.4wdtrips.net/forum/.%20%20http:/www.secondchancegarage.com/public/676.cfm) . The battery Brains monitors the battery charge and drain and disconnects the battery before the battery drains below a point where the vehicle will not start. I not sure what the specs are on how this works but does have me thinking it might be inexpensive insurance. Does anyone have any experience with this?

Regards

[darmbruster]

I really don't have an answer for that question regarding a FULLY dead battery (such as one in which one or more cells shorted out).

There might be enough juice left to trigger the fuel injector(s) and a spark plug or two. If gas and spark occure, then the engine should fire.
I think it does depend on how 'modern' the truck is, but I've had a battery that was too flat to turn the starter but had no issue pop starting it. In the end I think once you get the engine running, the electronics will work fine. This is the same with a EFI or carb truck, both need juice to fire the plugs and pop starting it will get the engine turning, which generates power with the alternator turning. It is easier to get a simple carb truck started this way because all it needs is spark, where the EFI truck additionally needs to have the computer coherent to fire the injectors. I have no idea what the minimum that my engine needs (it's a 22R-E), but it did pop start OK with the battery at ~9V.

[David A. Wright]

My '02 Tacoma has 105,000+ miles on it now and still has the same battery it came from the factory with (I bought it new June, '02). The above thread is exactly why I carry my power pack 24/7 in the truck ...

Fortunately the only times I've killed the battery is just after I installed my Hella driving lights, wired direct to the battery. The switch got knocked on a couple of times during the day when I didn't know it. A few minutes later when I went to start the truck, I got the click ... click ... click indicative of a dead battery. A quick hop into the back of the truck to retrieve the power pack, hook it up, and fire away.

[JPzKJ]

6 years on the same factory battery.....thats quite a trick, I' haven't been that lucky yet for sure ! Battery pack is a great Idea for sure...maybe it's time to spring for a new battery for that Yota ! I can vouch for the battery pack...great insurance when your out on your own...just remember to keep it charged :)

[JackSilb]

Hello,

Thanks to Mitch raising the idea, I got one of these units (http://www.solarcharger.com/Sunsei-Solar-Charger-SE-400). It is a way for me to play with Solar power and leave the battery conditioner out of the grid. The solar power panel is really well built. Lots of connection options including cables to daisy chain units.
In the website shows it costing $99, but if I am not mistaken, I paid $69 at Frys' electronics.

We will see how it works. I have something draining power from my truck's battery. If I don't run it for 3 weeks or so, I can't start it. I believe is one of the battery connectors with several cigarette light adapter that I have. It gets warm all the time. I need to play with a current meter to find out who is sucking the power, if needed, after I replace this easy one. Until then, this unit should help.

Thanks Mitch!
-JACK

[4RUNAMOK]

When did I suggest this? I am a firm believer in using solar panels to relieve a battery from harmful sulfation, but I just don't recall bringing it up recently.... did I?