oldfrat

After reading about this last week in the Dallas morning paper, I bought one and it arrived today. I find it a really neat product for those of us who own old cars that sometimes stay parked for a long time. It is a storage battery that will jump start a car, but is only roughly 6" X 3" X 1" and weighs only about a pound.

It loses only 2-3% of its charge a month. The manufacturer recommends you store it only 60% charged and recharge it to that level about every 3 months, but claims it will still start most cars if it hasn't been recharged in a year.

Super easy to carry in your car and way easier than carrying around jumper cables. Based on the instructions, also easier to use than jumper cables.
And it comes with attachments to charge your phone of laptop.

Here's a link to a $120 Amazon bundle that includes a free smaller storage battery.

As a disclaimer, I have not tried jump starting a car with it yet. But, I also didn't find any bad reviews of the product.

Brad

Speedtoys

They work great. They get the shi* beat out of them at auto auctions.

dr bob

Today's Harbor Freight flier includes a jump-start/power supply unit that has 12V lighter-sockets and a USB charger. $40. Has a 17AH wet lead-acid battery in it, and a charge sensor that will run the battery dead in a week or so (undocumented feature...). With a decent battery they last a few years, just isolate the charge sensor.

It's too big to leave in the car though. The lithium ion one would fit behind the tool panel, but I'd forget to charge it until after I needed it. Or I could do as Alan has done, and mount the same 17AH battery that comes in the H-F version someplace in the car, charged and ready.

potdog

HI every one, is the one at $120 the JS12 1200 M.H.A ,if it is they will not start a 928.Bought a similar thing in U.K. 1400M.A.H. there all made in China will not start my 928 or Audi a8 with flat battery ,was told by seller "sliding jack barker it would start up to 3 ltr diesel and 5 ltr petrol cheers.

dr bob

Seems many of them depend on being able to charge the installed battery some, and charge a capacitor in parallel to handle initial starter inrush to get the engine rolling. The tiny lithium-ion ones don't have enough available instant current available to crank the engine on their own.

Meanwhile, I tried one of the 17AH wet batteries as primary in a personal watercraft a decade or so ago, and on its own it would not crank/start the engine. I ended up with 35AH AGM batteries in the baby boats and never a worry. But those are way too big (U1 size) to haul around for casual use. So it seems that all of the small-battery models depend on sharing some current initially with the host battery, evidenced by the requirement that you have it connected for 10-15 mins before attempting to start.

oldfrat

Again, I have no experience jump starting a car with it yet. I bought the JS12 model. The packaging claims it will start gas engines up to 6.4 liters. The instructions do not call for waiting after connecting it.

Brad

dr bob

I guess we'll find out if it works shortly after you do.

hacker-pschorr

Are you referring to the model in question in the OP or jump packs in general? I've always been curious how well these smaller units work.

This has been my go-to unit when a jump pack is needed. Narrow enough to fit behind a seat and powerful enough to start my brother-in-laws F250 diesel.



I've found with a totally dead battery, they work better if you ground the pack to the engine vs the battery. It seams connecting them directly to the cars battery, you loose cranking power to the battery trying to charge. Might just be my imagination...

Speedtoys

Ya..I may have jumped...the answer.

The capacitor based ones...have been rock solid in the auction lots Ive worked at.

This is the one they use.

http://www.r2batterysaver.com/produc...aptop-charger/