Extra 12 volt battery

[TOMMY47]

Anyone carry a cheaper 12v car battery in case regular battery won't start vehicle.
I have a conversion van made into a camper. Also have an extra interior battery, charged by solar, to run various( both 12v and 110) appliances. Also have some extra 12v plugs hooked up to van battery.
In my shakedown trip to Shenandoah NP, I encountered heavy fog for several days and ran both batteries too low to start van and needed a jump start. I was parked for a couple of days, not running van.
I will be traveling through the Northwest NPs and expect I will be without sun at times.
This is the system I'm going with and won't be changing it. Does the extra battery seem like a good alternative, just in case?

[GoPackGo]

I added a battery isolator from Blue Sea to isolate the house and start batteries on my trawler. I think it's just what the OP is looking for.

Something like this -

https://www.bluesea.com/products/7650/Add-A-Battery_Kit_-_120A

[nevadanick]

I havent need it yet which is a good thing.

[DrewE]

CavemanCharlie wrote:

nevadanick wrote:
I have one similar to this http://www.cnet.com/news/pocket-sized-jump-starters/

Have you ever used it?

I didn't think battery technology has come that far along yet to be able to make it that small.

I'm doubtful. Interested ! but doubtful.

These are 6AH or 12AH batteries, or about 75 or 150 Wh. When you compare the energy density and physical dimensions to laptop batteries or lithium ion cordless screwdriver batteries, it's not really unbelievable. These just happen to be able to be discharged at a very rapid rate without (undue) stress/damage; but obviously they can't sustain that for very long without running out of juice.

[CavemanCharlie]

nevadanick wrote:
I have one similar to this http://www.cnet.com/news/pocket-sized-jump-starters/

Have you ever used it?

I didn't think battery technology has come that far along yet to be able to make it that small.

I'm doubtful. Interested ! but doubtful.

[nevadanick]

I have one similar to this http://www.cnet.com/news/pocket-sized-jump-starters/

[CavemanCharlie]

I agree the simplest way to solve the problem is to get a Jumper Pack. They are light and recharge up quickly.

They even have a spot to recharge your cell phone in a emergency.

[wa8yxm]

NOTE: The Link is an EXAMPLE of what I recommend.. I do not, however, recommend a 300 dollar model.

50-100 dollars, I like to have 750 or more peak amps though... Sams, Costco, your favorite Auto Department, all carry lower priced units than this link.

Ebay Jump Start Pack

[TOMMY47]

Thanks all. I think I've got the alternatives. I'll decide what will work best.

[Dakota98]

I agree with SeaDog,

Get a small generator & Never have to worry about another thing, period.

And if you still wanted to get a back-up battery, do so. You'd be able to re-charge one battery while the other is in use whether that is being charged by the solar ( weather permitting ) or generator.

[Sea_Dog]

Why not something like this?

http://www.atgstores.com/generators/sunpentown-tg-1000ca-1000w-20-hp-gasoline-generator-with-carb_52...

[DrewE]

I had a rather more lengthy reply, but it basically said what smkettner said while using a lot more words, so I've trimmed it down.

The usual practice is to have only the engine and vehicle related loads on the starting battery and everything else--everything that might be used while parked/camping--on the house battery. That way camping won't run down the starting battery, and the two batteries can be types best suited to their duties (deep discharge for the house battery, and a starting battery capable of supplying high current for the chassis). There's usually an isolator device to permit the vehicle alternator to charge the house battery; this is either a high current diode or a substantial continuous duty solenoid (relay) controlled by the ignition switch. If it's the relay type, it's easy to also add an emergency start button to temporarily connect them and have a sort of built-in jumper cables if your starting battery is dead for some reason while the house battery is charged.

[time2roll]

I would carry just a jump box for emergency starting. Probably some good jump cables with at least #4 copper wire.

Also consider a Trik-L-Start battery combiner to charge the chassis battery when you have good sun. Assumes you don't already have such a system.

If I carried an additional battery I would have it connected in parallel and put it in general service. In conjunction with this I would move those 12v connectors off the chassis start battery and onto the parallel house batteries.

[TOMMY47]

oz--the extra battery would not be used for anything else. Will just be stored in a trailer I'm towing until/if needed. Won't need much charging.
The 2 batteries I am carrying now are not connected in any way.

[TOMMY47]

donn-They're on totally different charging systems. Didn't run the engine while using plug. Strictly my carelessness. Had nothing to do with improper charging--just too much use.
Just trying to get ideas if similar events happened.
Jump starter is an alternate idea.