Battery "jump packs"

Thank you for the link wbwood, I think that will work.
I checked my jump pack. It is a Schumacher 400 amp and the inverter is 140 watt.
It is a lead acid type battery. So I should be able to charge it back up easily.
These very seldom get used, but it never hurts to have a back up plan and the ability to keep everything charged.
Thanks everyone for your help.

You can buy a male-male 12 volt plug on amazon...it will charge the schumacher in the car. But, you have to monitor it manually as you can overcharge it...

Some jump packs now use LiPo batteries, and should be charged only using the supplied cords for safety reasons (don't want to interfere with the BMS or charge limiters). If it uses a lead-acid battery, pretty much anything that works will be fine.

If you are trying to supplement battery power I recommend just adding an addition deep cycle battery and 200 watts of solar. The jump-box is just a crutch.

dockmasterdave wrote:
I have one of these in the tt for emergency jump starts, and have used it to run tv and ant booster in a pinch.
My question would be, if it is used, can it be recharged from my tow vehicle?
Can I make up a cord to go from the 12 volt receptacle on the jump pack, to a 12v accessory outlet in the truck?
Would I need to use a small inverter to charge it via the 120 plug?
I appreciate any opinions and look forward to the gurus setting me straight.

The short answer is: YES.. You can, in fact some of them come with what at 120 volts is called a "Suicide cord" (Double male) you can also buy cords already made up like this.

If there is room in the battery area you can clamp them to the main battery while driving as well but this does not always work as well

NOTE it may take a lot of driving to fully charge it.. HOURS.

We used to bring these along when tent camping all the the time. The fans and Incandescent lights would really do a number on them over night.. I still got a couple of those YELLOW ones around here somewhere but they need new batteries in the thm... Never did open one up to order new batteries.

google image

Now that LED lights are on the sceen I bet they would last a long time...

They don't have a very big AH battery in them and will not hold a charge for a long time when you are using them...

Back in the camping days it was always a bag full of D-CELLS and some white gas for the stove and heater to use. All you needed haha...

Roy Ken

The one I use charged with 110v

I thought it should be able to charge in the reverse of how it was discharged, but didn't want to damage anything.
I am NOT an electrical engineer, but I see a lot of comments on here from people who know a lot more than me.
Thanks for the opinions so far.

I bet a 100W inverter would charge the jumper-box. They have those little transformer plugs and the charging current is very low.

The one I had came with a male-male 12V cig plug to use the recept on the box and plug it in to the outlet in the truck/trailer. I don't see any reason why you couldn't do the same.