Mitch, I've heard of that before. Don't know if it's true or not.

Would make sense.

I was told a long, very long time ago, when jumping, to connect the cables, rev the engine/high idle it, for about 2-3 minutes. Shut the vehicle off, then start the offending vehicle and then disconnect the cables.

Still leery about doing that... that's why I don't recommend it.

 

Another thought is that if the other vehicle has a bad voltage regulator and it's putting out high voltage your vehicle will see that voltage too. Not good.

 

Manual, the technique you describe is what I've been told too. It effectively isolates/removes all YOUR vehicle electronics from the big voltage variation/drop that occurs when the jumped vehicle's starter engages. I see it as a perfectly safe way to jump start another vehicle. Just don't let the other guy move his ignition to ON or START while your ignition is ON.

 

Over the years, I've owned many of those devices. Some where flat out better quality. The best units, back in the day, were http://www.cloreautomotive.com/ . The old Sears DieHard brand was also reliable. Problem is that they are big and heavy!

In recent years, with lithium batteries, you no longer have to carry this huge, heavy box with a car or motorcycle battery inside of it.

The new devices are usually just a little bigger than a cell phone, weigh almost nothing, and fit in your glove box. Tons of them are sold online via Amazon, eBay, AliBaba......and most are not worth buying. You may be tempted by low pricing. But don't.

Note that you will have a battery 600 - 900 CCA under your hood. Don't buy a jump starter rated for less amp. Those 500, 400, 250 amp devices sold online will only leave you disappointed. Buy something rated at 800, 1,000, 1,200 amp or more. Now do a little more research. I have made the mistakes of buying a whole bunch of those, and sending them all back, because even if it claims 1,200 amp; it didn't work and couldn't start my 1/2 ton truck. Some were so bad, that they failed to start a Honda Civic. A few of those units would not even charge up correctly. Several units showed a full charge, then the charge level indicator dropped when the device was connected to the car. A few of the devices had battery clamps so small, I couldn't even get the clamps onto my battery terminals. Some units were so bad, they were dead on arrival. Completely dead. Nothing happens when you plug in a charger. Leave it overnight, and still nothing.

Secondly, you only need the jump starter. Don't buy a device for the flashlight, tire inflator, or cell phone charger. While it may be nice to get all the attachments, a free tire gauge, and a carrying case.....those are useless if the device can't start your truck.

Since I have already wasted my money, I will share what I have paid to learn. I have a couple of older cars that I don't drive often. A Honda, and an Explorer. I will intentionally install a couple of old batteries into the cars, leave the lights on and the radio on to drain the batteries overnight. I charge the jump starter overnight. Than I can test the jump starters in the morning. Most of you will not have the luxury of intentionally draining a car battery overnight, just for the purpose of testing a jump starter. Keep in mind that these cars are maintained and operable, and the old batteries I drain are only for testing. The rest of the time, there is a good battery installed, and they are driven several times a month. Just not daily drivers.

I may need to start anything from a motorcycle to a medium duty, flat bed truck. Very rarely, a heavy duty truck.......it can happen with really old equipment. The brand that I now use is Genius Boost. I have one in each car, 1 in the motorcycle's saddle bag, and I keep one in my garage. In the garage, I have a model GB150 rated for 4,000 amp. In the vehicles, I carry a model GB40 rated for 1,000 amp.

 

 

Glad this got sorted! I can say from personal experience that those jump boxes are worth every penny!

 

Only if you get the right jump box.

There is a lot of garbage on the market. I've seen them with 10 AWG cables. Only 200A starting current. Some just flat out do not work. And in some cases, the sellers are liars. They purposely misrepresent their product. They will advertise that their product has XXXX amp & XXXXX mAh; only for customers to test the devices and find out that the numbers are completely false, and nowhere near what the unit actually does.

In November 2017, I purchased a DBPower N01. Advertised as 1200A, there was a Lightning Deal price on Amazon. I did not rip the product open immediately. I wrapped it up and gave it away for Christmas. By the time the gift recipient discovered that it would not charge up, my Amazon.com 30 day return window was closed. Now here comes the good part.......I contact the seller.........and the seller responds August 2018......9 months later! I get a replacement. It does not work. I get another replacement. It does not work. They sent me 3 units, all defective. Then they send me a different model. DBPower DJS50. It worked. It charged up. It powered up. A multimeter showed 12V @ the alligator Nipple Clamp.

The problem is that it is now September 2018. It took 10 months, for the seller to deliver a working product. And the real problem is that I paid for a 1200A jump starter, and now I have a 600A jump starter. It's only half the power, but it works. Now I'll just have to go out to my medium duty truck, with my 600A jump starter, and not be able to start it because my jump starter does not have the proper amperage.

The seller sent an e-mail: So that is a lesson learned.

I still like those old, big, heavy jump packs. You could actually open it up and replace the battery on the inside. Then you can own the product forever! Problem is that they are big & heavy.

From what I see, the right person could take apart a lithium jump starter, and replace the battery. Those batteries are typically proprietary, and will not be an easily sourced part. Lithium batteries are usually good for 1,000 charges. So if you need to recharge the unit every 6 months, or twice a year, you'll need a new battery in 500 years. Not really. Realistically, if a jump starter is good for 5 years, then you have probably gotten your money's worth. Within that 5 year period, you may have used it a few times, charged it once or twice, and that $100 that you spent could be seen as only $20 per year. From there on, it's paid for, and keeps working until it doesn't work anymore and you will buy a new one.