Lithium jump starter fails on very low Jeep battery

[John From Detroit]

I have one of those, it usually works good if the battery is low.. but.....

They sense if they are hooked up to a car battery (read the voltage) and if the battery is low enough on my Jeep Grand Cherokee where the battery is under the seat and hard to reach but the "Jump points" are a couple of things under the hood, passenger side, it just goes into alarm mode as it did yesterday for the 2nd time.

FIrst time it did this I called for a Pro who used one of the heavy luggable AGM boxes (I now have a small one too)

This time I'm moving better (Way better) (I'm a bit mobility limited but no where near what I was) and brought it upstairs for testing.. Worked fine when I fed it voltage (This was yesterday)

So I need to take my porta-power radio box to the car for use later today so I took it down along with some jumper leads and hooked it up with a bit of help. now the radio box won't start the car (well of them might) but the "jumpers" are about 20ga so nope. they did, however convince the jumper to jump. and VAROOM.

I drove to Harbor Freight and got their smallest Lead Acid (AGM) box... Those do not have that sense if you are hooked up feature. But even if it's not the OOMPH it will "Trick" the little one.

And I can always use another "Luggable" for the radios

 

[TheBar]

I have a 1200 amp tire inflator and jumper. I keep it inside for power outages. In addition to a couple USB type A USB phone charger ports, it has a single 2 amp 120v outlet that will keep a 60w floor lamp illuminated. I tested it for 24 hours and it was still bright. Also tested a 10" table fan for 8 hours which would be a life saver in the summer.

Being a lead acid gel battery it is almost as heavy as a car battery but a lot more convenient. Its a little heavy to use as a tire inflator but it will top off all 6 tires. Not as fast as my Viair but I don't have to run 20' cables to the engine battery. But the best part is I can completely disconnect the RV engine battery and it will start the 460 ci engine by itself.

 

[Brad Buchanan]

I have a 1200 amp tire inflator and jumper. I keep it inside for power outages. In addition to a couple USB type A USB phone charger ports, it has a single 2 amp 120v outlet that will keep a 60w floor lamp illuminated. I tested it for 24 hours and it was still bright. Also tested a 10" table fan for 8 hours which would be a life saver in the summer.

Being a lead acid gel battery it is almost as heavy as a car battery but a lot more convenient. Its a little heavy to use as a tire inflator but it will top off all 6 tires. Not as fast as my Viair but I don't have to run 20' cables to the engine battery. But the best part is I can completely disconnect the RV engine battery and it will start the 460 ci engine by itself.

If I might ask, what kind of tire inflator did you get?

 

[NY_Dutch]

I have one of those, it usually works good if the battery is low.. but.....

They sense if they are hooked up to a car battery (read the voltage) and if the battery is low enough on my Jeep Grand Cherokee where the battery is under the seat and hard to reach but the "Jump points" are a couple of things under the hood, passenger side, it just goes into alarm mode as it did yesterday for the 2nd time.

FIrst time it did this I called for a Pro who used one of the heavy luggable AGM boxes (I now have a small one too)

This time I'm moving better (Way better) (I'm a bit mobility limited but no where near what I was) and brought it upstairs for testing.. Worked fine when I fed it voltage (This was yesterday)

So I need to take my porta-power radio box to the car for use later today so I took it down along with some jumper leads and hooked it up with a bit of help. now the radio box won't start the car (well of them might) but the "jumpers" are about 20ga so nope. they did, however convince the jumper to jump. and VAROOM.

I drove to Harbor Freight and got their smallest Lead Acid (AGM) box... Those do not have that sense if you are hooked up feature. But even if it's not the OOMPH it will "Trick" the little one.

And I can always use another "Luggable" for the radios

My lithium jump box works fine on my lawn tractor with a totally dead battery. My meter reads zero volts. It works well enough that I haven't bothered to replace the tractor battery for three years.

 

[bigbAZ]

FIrst time it did this I called for a Pro who used one of the heavy luggable AGM boxes (I now have a small one too)

What is a luggable AGM box? Is it just a regular battery with a carrying strap or something special for jumping dead vehicles?

 

[TheBar]

If I might ask, what kind of tire inflator did you get?

It is a Schumacher 1200 amp I bought about 8 years ago. I replaced the battery about 2 years ago. This is a newer model of the one I have. I've heard the DeWalt brand is maybe better but more expensive.

Before that I had an Everstart brand that jumped the battery ok but the air compressor was weak at high pressure and broke after a couple years.

Then I bought a ViAir compressor and plugged it into the Everstart cigarette lighter socket. Carrying both around to me was easier than stringing 30' of cables from the engine battery in the front to the back wheels to power the ViAir. If my tires are really low I still use the ViAir that way because it pumps more air.

What is a luggable AGM box? Is it just a regular battery with a carrying strap or something special for jumping dead vehicles?

I think he is referring to the type of box I have. This is a newer model of the one I have. It weighs 24 lbs. So the battery is just about the same as a small import car battery like a group 21.

 

[Wmlunt-WO]

I’ve used the “Jump Smart” lithium jumper on my 2020 GC Hemi V8 and it works to turn it over after sitting for a month and a half.

 

[John From Detroit]

What is a luggable AGM box? Is it just a regular battery with a carrying strap or something special for jumping dead vehicles?

The Bar nailed it, it's lead acid batery (AGM type) in a carry case around 20-30 Amp hours generally.

 

[John From Detroit]

I’ve used the “Jump Smart” lithium jumper on my 2020 GC Hemi V8 and it works to turn it over after sitting for a month and a half.

I've used mine several times too with success but alas it does not work on my jeep when the battery is low unless I trick it into thinking the battery is not that low.,

 

[gwinger]

Some of the newer jump packs have a feature to bypass the "low" battery problem.
My Anitgravity has a "boost" button. It will start even if the battery is below the minimum required voltage.

 

[Wmlunt-WO]

I've used mine several times too with success but alas it does not work on my jeep when the battery is low unless I trick it into thinking the battery is not that low.,

How do you trick it into thinking it is not low battery?
Thx! Bill

 

[John From Detroit]

Part of this is due to the way the jeep is wired with teh lugs under the hood and the battery under the seat. Likely would not have worked otherwise but I jumpered n a small LiFePO4 battery I use for portable radio operation.. Did not have enough "oomph" to start the car but had enough to signal "Connected" to the jumper that did.