12V Jump Start Packs?

[verdesard0g]

As long as you get a good one they work fine. The smaller cables and clamps don't matter for the short time they are in use. Be careful, don't leave in a hot car in the desert, the batteries will swell and could burst and start a fire!

 

[john61ct]

I think lots of your vehicle interior would be melting long before that point.

The cells operate just fine in high **ambient** temperatures.

The (yes pretty high) fire risk is from thermal runaway of internal chemical processes

and (in theory) the BMS electronics are designed to prevent that.

Once you notice they're losing their oomph, say 100 uses or after a couple of non-abusive years, toss and buy new.

Would be nice if they made ones with user-replaceable cells, even top-notch ones would only be $50-80 delivered.

Be great to be able to just add the circuitry to an already existing battery bank, like the Yeti, or an eBike pack.

 

[verdesard0g]

Do a search for swollen jump pack....you will find a bunch of them.

 

[luthj]

Most of those cells have an absolute max temperature of 130F. A car can definitely got hotter than that in some places.

 

[Martinjmpr]

I just picked this up from Amazon:

Amazon.com: BEATIT G18 2000Amp Peak 12V Portable Jump Starter (Up to 8.0L Gas and Diesel Engine) 21000mAh Power Bank With Wireless Charger Smart Jumper Cables: Automotive

Buy BEATIT G18 2000Amp Peak 12V Portable Jump Starter (Up to 8.0L Gas and Diesel Engine) 21000mAh Power Bank With Wireless Charger Smart Jumper Cables: Jump Starters - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

Haven't tried it yet. One thing I like about it is the ability to charge "on the go" via one of the many USB ports on the F-150.

It comes in a nice little zippered carrying case and I plan on taking it on our camping trips, probably won't leave it in the truck.

 

[calicamper]

I use costco packs haven’t had any issues starting big v8’s. One thing tho they look for low voltage before they power up. I’ve had them simply not power up on dead flat batteries. But put a 9v battery on it and they power up.
They are all pretty much made the same exact way and come from china. Buy a cheap one using decent anderson plugs and use it to charge small usb devices and charge it regularly to cycle the battery.

 

[john61ct]

Correct me if I am wrong, but my understanding of this battery packs discussion is;

When you connect the batteries. The higher voltage from the higher voltage battery flows to the lower voltage. Like water and a siphon hose between 2 buckets, they will continue to flow until they are level. If you were to connect the jumper battery for a while before cranking on the starter. The lower voltage battery would increase (rise) to bring up the battery. Then the heavy combined amp draw would not be put on the jumper battery, but split between the 2 batteries. This would reduce the the draw on the jumper pack when cranking on the starter.

The quick connect and crank of the batteries and run the starter motor as well, right off the get-go, the jumper battery is trying to bring up the charge of the dead battery and start it at the same time. This is a big drain for the smaller lithium packs wires and can be to much draw for the (as was pointed out (2 gage wire)) wire to handle. In my view this could be a operator mistake. Would the quick connect method work if the original battery was partly charged or a small engine not needing that much power to kick over the motor? There is a good chance it will work. For a heavily discharged battery and a larger engine, maybe not.

All depends on just how bad the Starter batt is.

If a healthy newish batt you just left the radio going too long no problem.

If old and worn could suck all the juice out of a dozen jumper packs and still not start.

Sometime like an internal short, have to disconnect the old Starter to crank and maybe even leave it that way with the powerpak in place to get the rig home.

 

[john61ct]

They have a limited lifespan, cycling them to charge your gadgets is **not** a good idea if you might end up stranded in Death Valley.

Leave it charged, test it monthly and top it up, should be fine for two years then replace.

Get a separate one for your gadgets.