Which car jump starter should I have bought.

[micky]

I finally bought a mini-battery-jumper. I shopped carefully, I thought. I bought this. It and its wrappings are like new without a bit of dirt and I can still return it. It was only 3 or 4 dollars more than the next choice, and it is 2000A instead of 1500 and it has two USB-A, one USB-C, and a tubular output jack*** for charging things They both have flashlights.

I didn't buy this: It has only 1500A and only 1 USB-A output jack total. BUT, somewhere it says that it will jump totally dead batteries, by your pressing the Boost button.

How to decide which feature is more important. Well, none of the very clear, labeled pictures even showed a Boost button, and I figured they are really all the same, one can be bigger than another, but otherwise they all work the same and the only difference is the advertising.

So I bought the first one. Would you have done that? Do you think they are really all the same?

B) So they've delivered it and it's nice, but I notice this label on the end with things they never said in the advertisement:

Do not crank the engine for more than 3 seconds** Allow the jump starter to cool down for at least 1 minute between each starter attempt. Please ensure the device is at least 50% power before use. --- When I read this 3 days ago I thought it meant the car had to be 50%+, and I thought that proves it's not as good as the one that says it can jump totally dead cars. Does it? But maybe it means make sure the jump starter is +50%. Which is it?

**Doesn't my car sometimes take more than 3 seconds even when it's working fine?

So all these warnings are making me think maybe the second one above would have been better??? (Although it might come with lots of new warnings too!)

C) I went back and looked again at customer comments for the first one and three people praise that boost button: 1) ...off too early and battery was completely dead) no problem. Be sure to use the boost button if it is completely dead. 2) ...manual on this unit states that even with a totally dead battery, pressing the boost button will charge it. I don't yet have a dead battery to test it on, but so far, it looks positive: Pros: boost button, very small and lightweight, even.. 3) This jump starter can start a completely dead battery by pressing the boost button.

Well, only one of the three says he used the boost button. (One cites the manual and one says it can without saying how he knows.)

So is the second one, the one I didn't buy, better? Does it really have a boost button? (Even though the picture doesn't show a boost button. Maybe they haven't upgraded the pictures.)

OTOH will the first one also start a completeky dead battery? Because they are raally all the same? Will the first one in practice start every car the second one will?

***Yes, it's really an output jack, though it's a cyclinder with a center pin. I've never seen that before but it says it's 12v, 10A.

[Clare Snyder]

I have one of each - the "boost" button is NOT on the pacl - it is on the "booster cable" - as is the "reverse connection" warning light

[invalid unparseable]

I have owned this kind of jump starter for decades. Most of them have idiot-proof protection to prevent reverse polarity connection and short-circuit connection (accidentally banging the clamps together when handling). When the car battery is totally dead with terminal voltage close to 0V, after connecting the clamps to the car battery, the booster's computer would think that you have short-circuited the clamps so it won't energize the clamps (because there will also be 0V across the clamps when you short-circuit the clamps). The "boost button" is to over-ride this.

Lithium jump starter pack (booster pack) can provide very high current output but the totally capacity is quite small. If your engine cannot start within 3 seconds, you should give the booster pack a rest before you try again. I suggest you turn off the booster pack when resting between jump start attempts.

It is always advised that you should avoid using a lithium battery when the capacity has dropped to below 40% in order to extend the useful life of the lithium battery. This holds true for cellphones and laptop computers too.

Besides, a lithium booster pack has 3 x 3.7V lithium cells inside, if you use the booster pack to jump start when the internal cells are weak, there is a chance that one of the cells may dip to zero volt and get reversely-charged during the jump starting process. That will greatly shorten the life of the whole booster pack. This is also true for traditional sealed lead-acid booster packs.

Another useful tip is that you should try to crank your car engine as soon as possible after you have connected the booster clamps to the dead car battery. Don't try to use your booster pack to charge the dead car battery because booster pack can provide high current output for only a short time due to the small size of the internal battery pack. Connecting the lithium booster pack to the dead car battery without attempting to re-start the car immediately will drain the internal battery of the booster pack. You will end up with two dead batteries - your booster battery and your car battery.

[Thomas]

I have the iClever 600/15000mh with a boost button on the cable part. It does do dead jumps. It amazes me whenever I use it. It will not jump that dead bat without pushing the boost button. I know it works but cannot elaborate on how.

[invalid unparseable]

The booster thinks that you might have short-circuited the clamps when you connect the clamps to a dead battery. When the battery is totally dead, the terminal voltage across the battery is 0V. When you accidentally bang the clamps together while handling, the voltage across the clamps is also 0V. The booster cannot tell the difference whether you have connected the clamps to a dead battery or accidentally banged the clamps together. You have to press the button to confirm that you have connected the clamps to the battery correctly.

This is a safety feature so that you would not cause an explosion if you short-circuit the clamps or connect the clamps to the battery in the reverse polarity.

If your car battery is not totally dead, like having 10V terminal voltage for example, the booster will know that you have connected the clamps correctly, and probably doesn't require you to press the "boost button".

[Bob F]

My suspicion is that mine unit does not source current until it senses the voltage drop of the engine being cranked.

[invalid unparseable]

I have not seen one that does what you said.

The sealed lead-acid battery type booster has wrong-polarity warning and a manual rotary switch for the user to actually switch on the large current source. Apparently before you turn on the large current source, the clamps merely function as voltage detector for the booster.

The lithium battery type booster has push-buttons, and every time I use it I can hear a relay inside booster activating the internal connector.

[micky]

That makes sense.

That makes sense, and it means it's probably true for all the other models too.

So they meant the booster, not my car battery. When I thought they meant the car battery, it was the contrast from the other one, which could jump a totally dead car, that bothered, me. But the one I got still won't jump a dead car and the other will.

Except the one with the boost button is out of stock now!

There are 3 bigger sizes, 2500A, 3500A, and 4500A (for more money**), by the same company as the one out of stock, and scores of other models by loads of other brands, but I don't feel like checking them out.

**I hate to spend even more money, and they take up more room. I'll probably never need this in the first place. I have a device called Priority Start***, that disconnects the battery when the voltage gets too low and reconnects it when you put your foot on the brake. Plus I'm still going to carry battery cables (unless my next car is really small.) ***OTOH, there was no room for Priority Start when I first got this car. Not until I replaced the battery with a smaller one (which Autozone claims is just as good) was there room.

Also the extra 2 charging jacks don't mean much. I'm probably never going to charge anything from it, since I already have a car charger, and if I did charge sometthingit would be only one thing, not two at a time. It's not like I go camping for days and need to charge things.

Hmmm.

Okay. Makes sense.

[micky]

I thought for sure I answered you already but I don't see it now. ??

I said I was glad to hear the ad had not lied to me.

And now looking at a picture of the *cable*, I see the boost button.

[micky]

Good enough. I think I bought the wrong one, but now the other one is out of stock. I hate returning thigns anyhow, not because it's a nuisance for me, but because it's a nuisance for them.

[micky]

Duh. Maybe I should have thought of that, but I'm happy to hear they are not lying (and forging reviews!)