Auto jump start packs?

[Hawkmoon]

My faithful old jump start box finally kicked the bucket. It doesn't owe me anything -- it's more than 20 years old -- but new ones are expensive, and it seems a lot of the new ones don't perform as well as the old ones.

Has anyone ever just replaced the battery in one of those and brought it back to life? The circuitry in mine seems to work, but the battery won't hold a charge.

[KD5NRH]

Has anyone ever just replaced the battery in one of those and brought it back to life? The circuitry in mine seems to work, but the battery won't hold a charge.

If you can get in there without destroying it, go for it, but do make sure you use a battery suited to massive rapid discharge. The results of pulling starting current from batteries made for low drain applications can get ugly fast.

[230RN]

Mine from Harbor Freight wasn't all that expensive.  Had it two years, only used it once, worked great.  Left a light on in the car over two or three days, killed the battery.

I'm curious as to why you need one as often as you imply.  Are you servicing a fleet?   Might be time to diagnose a problem with the vehicle.  Perhaps an unexpected drain on the battery while the ignition is off.  (Had that happen once ---cigarette lighter half in/half out of the socket.)

I have long suspected that about 50%* of any jump-starting technique's effectiveness is simply due to kicking the on board computer into action.  Ante-on-board-computers, I remember starting cars with pretty darned low batteries.  Shhhh.  Don't tell anyone I suspect that, lest someone accuse me of being a luddite.

 

Terry

* Arbitrary Plucked-From-the-Air (PFA) number, not a genuine statistic.

[Hawkmoon]

I didn't say anything that I can see implies needing one often. In fact, I believe the problem is just the opposite. I am a widower with a number of old Jeeps, but I can only drive one at a time, so some of them may sit for months without being driven, or even started. I try to keep the ones within range of the garage on battery maintainers, but I can't do that for all of them. I don't use the jump start box often, and I believe I allowed it to run down without recharging often enough that the battery lost its ability to hold a charge.

Looks like Amazon has a direct replacement for the battery, for $31. I'm going to take a chance on it, because I hate discarding something that's not really broken. And new ones seem to start at around 100 bucks, and they all seem to include work lights or compressors, or both. All I need is a jump starter box.

[230RN]

I am a widower with a number of old Jeeps, but I can only drive one at a time, so some of them may sit for months without being driven, or even started.

OK, so "fleet."

I charge mine up about once a month.  One of the worst things you can do with a battery (of almost any kind) is let it run down, since one cell must have lower capacity than the others.  So further discharge through any connection reverse-charges that one cell.  Bad.

Reverse-charging one (or more) cells.  Consider a 12V battery with six 2V cells in series, one cell completely dead, that is, cell 3=0 voltage.  Terminal no-load voltage would show as 10V or less:

| (+ -/+ -/0 0/+ -/+ -/+ - )  |
|                                        |
|                                       ^
------>connection flow>-----^

Note that connecting the outside terminals of the battery with any load results in current flowing from the minus internal terminal of cell 3 to the positive terminal, resulting in its being recharged in the reverse direction from the other good cells.

Note this is not true if cell 3 is internally shorted.

Note this is NOT true of a "battery" with only one cell.

Note also I am not just writing this for the OP.

Conventional current flow assumed.

Edited for housekeeping.

Terry, 230RN

[Firethorn]

Maybe some of those solar trickle chargers?  It would extend your reach.

http://www.homedepot.com/p/Coleman-2-Watt-12-Volt-Solar-Battery-Maintainer-58012/203241468?cm_mmc=Shopping%7cTHD%7cG%7c0%7cG-BASE-PLA-D27E-Electrical%7c&gclid=CPWw2q_R3NMCFQ6dfgodzQUFrg&gclsrc=aw.ds

https://www.harborfreight.com/15-watt-solar-battery-charger-68692.html

But good luck on just replacing the battery.  I've done that with my UPS units multiple times.

[Hawkmoon]

But good luck on just replacing the battery.  I've done that with my UPS units multiple times.

That's next. I have three American Power Conversion UPS units with dead batteries, and I need to get at least one of them up and running.

[charby]

I am a widower with a number of old Jeeps,

Time to let some go?

[zahc]

Technically on-topic, does anyone have experience with the new lithium jump starters? The local warehouse club has units about the size of a multimeter or so, that have lithium batteries and claim they can jump start engines up to 4 liters.

[Hawkmoon]

Time to let some go?

"They don't make 'em like that any more." It is definitely NOT time to let some go, because Jeep doesn't make anything today that's even remotely like a real Jeep. Heck, even the Wrangler isn't suitable for off-road unless you spend a pile of money reinforcing the front axle tubes and Cs.

[Hawkmoon]

Technically on-topic, does anyone have experience with the new lithium jump starters? The local warehouse club has units about the size of a multimeter or so, that have lithium batteries and claim they can jump start engines up to 4 liters.

Those are what I want to avoid. I don't trust lithium batteries.

[Triphammer]

On UPS batteries, "Batteries Plus" will match & swap out UPS batteries for just the cost of the batteries.. Plus THEY get rid of the old batteries.

[Firethorn]

Technically on-topic, does anyone have experience with the new lithium jump starters? The local warehouse club has units about the size of a multimeter or so, that have lithium batteries and claim they can jump start engines up to 4 liters.

I have one, it started my Tacoma just fine in the winter when I screwed up and left my lights on.

It's about the size of a multimeter, came in a nice box, and can charge my cellphone and tablet.

[KD5NRH]

I am a widower with a number of old Jeeps, but I can only drive one at a time, so some of them may sit for months without being driven, or even started. I try to keep the ones within range of the garage on battery maintainers, but I can't do that for all of them. I don't use the jump start box often, and I believe I allowed it to run down without recharging often enough that the battery lost its ability to hold a charge.

Since you're not using several for long periods of time, and most likely aren't heavily computerized, why not pull the batteries on the ones not near the garage?  Maintain one or two and just drop them in as needed.  Not sure if they're still common, but I used to get tool-free heavy duty quick disconnects reasonably cheaply.

[Frank Castle]

"They don't make 'em like that any more." It is definitely NOT time to let some go, because Jeep doesn't make anything today that's even remotely like a real Jeep. Heck, even the Wrangler isn't suitable for off-road unless you spend a pile of money reinforcing the front axle tubes and Cs.

https://youtu.be/MvgN5gCuLac

[AJ Dual]

Technically on-topic, does anyone have experience with the new lithium jump starters? The local warehouse club has units about the size of a multimeter or so, that have lithium batteries and claim they can jump start engines up to 4 liters.

In terms of actual ability, the energy density in a LiPoly brick is absolutely there to crank even some rather large diesels.  And those suckers can dump amps in pound-for-pound the way SLA can only dream of doing. So in the most basic terms of "does the tech work?" the answer is a definite "yes". They're not a rip-off, and will do what they say they do.

However, because the application hit our shores pretty much immediately in the manner of lowest-bidder Chinese commodity item, there's a lot of "and, if, or but..."  And a 8000 - 16000 mAh LiPoly that gets angry is one hell of a incindendary device. And cold and hot will affect the battery too. So it might not be at it's best if left in a freezing glove box, or in a 120 deg. + car in summer.

I'd probably lurk car forums and see if there's a thread on these, and if they have brand recommendations for the types who are jumping cars repeatedly with them and haven't had one go kablooey on them.

[230RN]

Those are what I want to avoid. I don't trust lithium batteries.

And as touched on by AJ Dual.

I'm kinda with you on that, mainly becuase I don't understand the rather ticklish handling and charging requirements.  Also, I've heard of a couple of recalls of Li-powered devices by rather large and supposedly reliable companies because of their fire danger.

And I seem to recall some plane crashes where a cargo of Li batteries was suspected of being the cause.

I'm amazed at the energy density and output power they can provide; my sons have Li-powered R/C aircraft and the energy specs on those batteries boggled my luddite brain.

I mean, like 10A output for 10 minutes from something you can hold in your palm.

But then I remembered that power = energy / time, and as time approaches zero, power becomes astronomical.

So they don't like being shorted out, either internally or externally, and apparently a lot of things make them short out.

Including connecting them to a dead automotive battery, which looks like a dead short to any charging supply.

Which my ancient Sears plug-in-the-wall charger can handle.

Terrified Terry

[KD5NRH]

I'm kinda with you on that, mainly becuase I don't understand the rather ticklish handling and charging requirements.  Also, I've heard of a couple of recalls of Li-powered devices by rather large and supposedly reliable companies because of their fire danger.

All my cheap Chinese lithiums (i.e. not the packs for the smartphones, laptops and tablet) charge in the dirt floored, rock walled garage.  If they flare up high/hot/long enough to light the wood ceiling, I guess that could be bad, but fairly impressive too, since I never have more than a 2s/2p 18650 pack charging at once in one place.  Worst case would be if the pack for my bike headlight lit off while charging attached to the bike, and trashed the aluminum frame.

[230RN]

^ You're sure that bike is aluminum-framed?  Not.... Mg?

Yes or no will do, lest we run off into a thread drift.

But I was glad to see that others also have concerns about Li batteries.

[KD5NRH]

^ You're sure that bike is aluminum-framed?  Not.... Mg?

Always seen it listed as aluminum.  Haven't tried to light it.

[Declaration Day]

Has anyone ever just replaced the battery in one of those and brought it back to life?

Yes, I have on a few different models, without any trouble.

[lupinus]

I have one of the Stanley branded units from Walmart. Even has work lights so you can see what you're doing and a slow but usable air compressor.

Price wasn't bad and I've had it for a few years now. Holds a charge fine and works like a champ both times the crappy Ford battery went tits up two winters in a row and needed several jumps before I could get a new battery.


Sent from my iPhone using Tapatalk

[KD5NRH]

However, because the application hit our shores pretty much immediately in the manner of lowest-bidder Chinese commodity item, there's a lot of "and, if, or but..."  And a 8000 - 16000 mAh LiPoly that gets angry is one hell of a incindendary device.

https://youtu.be/ZTzEHsJVZhA

[AJ Dual]

https://youtu.be/ZTzEHsJVZhA

18650? Pfft. That's about 2500mAh tops.

Here's an 8000mAh brick like for RC cars, quadcopters, and a lot of these car starters.

https://youtu.be/tatq8KcaGY0

Granted, he did a direct short piercing several layers of the cathode, anode, and flammable electrolyte all at once, but honestly, it's almost better if it's mostly all over at once like that, rather than a drawn out continuous fire.

[Ben]

I'm not sure of the differences between Li-Ion and Li-Po, other than I think Li-Po has more energy per unit, but I'm pretty sure all the car jump starters are Li-Ion.