[NA] Boosting batteries

Let'sgoflying!

Let'sgoflying!

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Dave Taylor
Here is a thought I have never seen suggested; perhaps there is a good reason why - let me know.

I am talking about boosting the 12v auto battery you have in your truck or car.
I don't normally boost aircraft batteries.

Here is the TLDR for you:
A family member bought one of these tiny "Lithium ion" battery boosters. (no where can I find the actual chemistry on the packaging/label) "1000A 12V 24W"
Several people have said that it will start a vehicle that has a battery which is completely dead.
An employee says hers will start her PowerWagon Diesel from dead.
So I hook mine up to a dead car(the car battery is 6mo old); fresh charge on booster battery; good connections...and it doesn't have enough to crank the car. The interior lights do come on. (it's a ~5L engine which starts fine with a charged Pb acid battery).
The booster mfgr says it will start a 6L engine with a dead battery.
I think these promises are optimistic, and that the boost battery can help a weak battery but not start a dead vehicle.

Anyway, I'm thinking could this be a solution (or could it harm the vehicle)?

Can I remove the dead vehicle 12V Pb-acid battery from the circuit and then the boost battery might start the dead vehicle?
The dead battery is probably presenting a large drain on the boost battery once the booster battery is connected.
Removing the dead battery, then starting the vehicle, then reconnecting the dead vehicle battery might work.
Can any harm come to the vehicle's circuits from this?


A46A5456-E8F2-4C7A-B916-0C23D37135BD.jpeg
 
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Yes harm can happen if you try to run it with no battery while trying to change it.

I doubt it will start it by itself, only one way to find out. If it did start it I would be very surprised and would not try to swap in the dead battery with it running.

IMO so many think it is OK to lie about stuff nowadays to sell a product.

It probably would be enough to start something with a low battery but dead is a different story and the battery might be permanently damaged?
 
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Just as a point of reference I have started my O-360 with the model pictured with no problem. Did it just to test if it would work. Cranked right up.
 
Most of the jump packs I’ve been around have a smart enough circuit to detect when there isn’t a battery in the circuit it is connected to. So it might work with the battery disconnected but I’d be surprised.

As mentioned above, damage can be done if you do get the thing running and the charging system is trying to charge a battery that isn’t there.
 
There’s a “boost” button on many of them. It ups the amps for a brief period. I have one and it works awesome. Started my diesel from full dead after leaving the lights on for several days.
 
Keep in mind that simply clamping onto the cables that are connected to a dead battery may not work if the battery connections are not clean and tight. Many cars will experience a low battery when the charging system and battery are both good but the connections are dirty and/or loose.
 
Let'sgoflying! said:
Here is the TLDR for you:
A family member bought one of these tiny "Lithium ion" battery boosters. (no where can I find the actual chemistry on the packaging/label) "1000A 12V 24W"
Click to expand...
Some big mistake there somewhere. 1000 amps at 12 volts is 12,000 watts, not 24 watts, however briefly. Sounds really optimistic anyway. 24 watts would be 2 amps.

It might be a bit like the Craftsman power tools ratings of some years ago. Maybe they still do it. A 3-HP compressor that runs on a 115 volt, 15-amp circuit. 3 HP is over 2200 watts, which is over 19 amps, and that assumes a 100% efficient motor, which does not exist. I think they were measuring the very brief inrush starting current and multiplying that by 115 to get the wattage high enough to claim 3 HP. Most people are ignorant of stuff like electrical theory and are easily fooled by advertising hype.
 
Dan Thomas said:
I think they were measuring the very brief inrush starting current and multiplying that by 115 to get the wattage high enough to claim 3 HP.
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They include "Inertial Horsepower" - measure the peak torque (and RPM) when a brake is rapidly applied. You can pretty much get any number you want that way.
 
Dan Thomas said:
Some big mistake there somewhere. 1000 amps at 12 volts is 12,000 watts, not 24 watts, however briefly. Sounds really optimistic anyway. 24 watts would be 2 amps.
Click to expand...


Here’s the labels
“6L engines”
“24Wh” (I did miss the “h” next to watts)
But I agree with the advert hype.
Even specs can be full-on lies, esp with Chinese products.273FB50C-77A0-4077-A05E-36727C49D939.jpeg


F664F846-3763-4133-8A3A-EBD271FF2074.jpeg
 
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Daleandee said:
Keep in mind that simply clamping onto the cables that are connected to a dead battery may not work if the battery connections are not clean and tight. Many cars will experience a low battery when the charging system and battery are both good but the connections are dirty and/or loose.
Click to expand...

Good connections. I must have failed to mention
 
Several have said boosting with the ship’s battery disconnected ‘could’ be bad…so til I hear a more authoritative “It’ll be fine”, I believe I’ll hold off.
 
Let'sgoflying! said:
Here’s the labels
“6L engines”
“24Wh” (I did miss the “h” next to watts)
But I agree with the advert hype.
Even specs can be full-on lies, esp with Chinese products.View attachment 108489


View attachment 108490
Click to expand...


That's 24 watt-hours, not 24 watts. It's a measure of the battery's capacity. The battery should be able to provide 24 watts for an hour. But the number looks really low. It would be equivalent to only 2 amp-hours. That's a pretty small capacity.
 
Smart chargers are great and I use several, but need some voltage to work.

I still have my 38 year old craftsman 40 amp roll around charger with like a 125 amp starting boost? I recently put it in my pickup truck and hauled to the airport to start a friend’s car after he got back from a week trip. He couldn’t believe how old it was! It is better than any jumper cables and will bring some battery’s back to life with it’s amp’s. Still a very important charger to have.
 
Half Fast said:
That's 24 watt-hours, not 24 watts. It's a measure of the battery's capacity. The battery should be able to provide 24 watts for an hour. But the number looks really low. It would be equivalent to only 2 amp-hours. That's a pretty small capacity.
Click to expand...
At 1000 amps and 12 volts, 24wH means a thousandth of an hour. 3.6 seconds. Sounds about right. Of course, the voltage will drop under load, decreasing the current flow and lengthening the discharge time. And not many starters draw 1000 amps anyway.
 
For comparison, a typical car battery will have a capacity somewhere around 50 to 75 amp-hours.
 
Short answer to "can it hurt the car to start it without a battery?" is yes. Might not hurt it all, might fry some of the electronics. Automotive electrical systems are designed around having a large battery in the mix, which reduces the severity of over voltages and reverse voltage surges. Now, any decent bit of electronics should be tolerant of something like -12 to +40V or so, compared to ground, but I don't know if they all are, and I don't know if the surges could exceed that. To me it's a roll of the dice, and you risk losing the alternator/voltage regulator or one or more computers.

I have one of the lithium booster chargers, and they usually work great. But sometimes they don't. So I also have a conventional set of heavy duty jumper cables. They always work.

For what it's worth, in my experience the leading cause of battery problems are corroded terminals, second leading cause just old batteries, and probably the third things that draw power when the car is off that shouldn't, continually draining the battery.
 
Using a booster to start the engine with the main battery disconnected might not hurt anything, but running the engine without a battery might, most voltage regulators require the load of a battery to operate properly.
 
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I have a HALO jump start battery and it has started the following:

- wife’s Cadillac
- my Subaru Forester
- 20 Hp garden tractor
- Cherokee 140
- 6 cylinder outboard motor
- various other cars

A few lessons to note. (1) It will NOT work if the vehicle battery is bad. The jump starter puts a quick charge in the vehicle battery. It is the vehicle battery that provides the slugs of current for the starter. If the battery is weak and will not take or hold a charge it will not work. (2) Based on #1 you must allow the jump battery to charge the vehicle battery. It may take more than one charge cycle to put enough charge in the vehicle battery to spin the starter.
 
Dana said:
Using a booster to start the engine with the main battery disconnected might not hurt anything, but ruining the engine without a battery might, most voltage regulators require the load of a battery to operate properly.
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ummm...interesting typo...

(sorry, couldn't resist :))
 
Bob Noel said:
ummm...interesting typo...

(sorry, couldn't resist :))
Click to expand...

Yep ... but he also makes a point that is very helpful. Sometime when trying to boost a car people connect the cables and turn the key. Allowing the low battery to be charged for a few minutes really increases the odds of a faster start.
 
It is not so much the dead battery being charged to do the start, it is that a very low battery takes a LOT of amps trying to charge.

So giving it a while when jumping, lowers the amp draw by the low battery.
 
Am I the only one wondering why not just replace the weak/bad battery? In the time it took to read this thread I could have run to the store and got a new one.


Dan Thomas said:
It might be a bit like the Craftsman power tools ratings of some years ago. Maybe they still do it. A 3-HP compressor that runs on a 115 volt, 15-amp circuit. 3 HP is over 2200 watts, which is over 19 amps, and that assumes a 100% efficient motor, which does not exist. I think they were measuring the very brief inrush starting current and multiplying that by 115 to get the wattage high enough to claim 3 HP. Most people are ignorant of stuff like electrical theory and are easily fooled by advertising hype.
Click to expand...

Explains why my Craftsman compressor won't run on a 15 amp circuit in my garage, unless it is the only thing on the circuit. Once past the initial start up surge, I can turn the light back on.
 
midwestpa24 said:
Am I the only one wondering why not just replace the weak/bad battery? In the time it took to read this thread I could have run to the store and got a new one
Click to expand...

For your plane?

If I get to the airport and my plane's battery is dead, I can jump it (or hand prop it) and go flying, instead of waiting several days for a battery.
 
I’m trying to remember the last time I had to jump start a car I owned…

I guess it was about 2016 or ‘17. That’s when we discovered that the starting battery in my wife’s Fusion Hybrid was dead, and also had been milled from a block of solid unobtanium.
 
Dana said:
For your plane?

If I get to the airport and my plane's battery is dead, I can jump it (or hand prop it) and go flying, instead of waiting several days for a battery.
Click to expand...

The original post was about a car, not an aircraft.
 
midwestpa24 said:
Am I the only one wondering why not just replace the weak/bad battery? In the time it took to read this thread I could have run to the store and got a new one
Click to expand...

Where the OP lives, the nearest WalMart is a three-hour drive away.
 
I have a few EarthX Jump packs and one NoCo equal. They all work great. Well, if starting a DEAD battery in an airport garage at 2:00 in the morning in -20° qualifies as great to you. My Jump Packs will start multiple dead vehicles between charges. Standard gear in my day pack.
 
Southpaw said:
My closest Wal-Mart is in a Foriegn country. You don't want to move here. ;)
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You mean Canada? I don't know...to me that part of Canada seems less foreign than some parts of the US. I remember when walmart didn't exist, and it was better times all the way around. No idea why we've let them exist. Ok, I do...we're short sighted, cheap, and lazy, overall.
 
Albany Tom said:
You mean Canada? I don't know...to me that part of Canada seems less foreign than some parts of the US. I remember when walmart didn't exist, and it was better times all the way around. No idea why we've let them exist. Ok, I do...we're short sighted, cheap, and lazy, overall.
Click to expand...

And apparently, a whole bunch of people were craving a store they could go shopping at in their pajamas. :D
 
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