atikovi
Well-known member
I have many cars in storage that don't have a battery. Can the lithium jump starters be used to move or drive the cars without the battery installed?
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Can lithium jump starters be used without a battery?
- Thread starter atikovi
- Start date
Yes, technically, it works depending on the specific requirements of the car. But they are not meant for a sustained load, and this can and likely does overheat them. Not something you want to do to lithium-ion polymer packs which pretty much all of these use.
kctyphoon
Banned
All depends on the ACTUAL amperage you can supply, not "peak amps"..
rlitman
Well-known member
I'm going to say sort of, but it's not a great idea.
One issue is that the smart clamps will not close their protection relay unless they sense some battery voltage. Without that, they don't know whether or not your polarity is reversed. There is usually a hidden button to override this, but that then overrides all of the safeties, including the timeout that prevents you from burning up the battery (these have a VERY short thermal duty cycle), wires and clamps.
Another issue is that while it may run for long enough to spin the starter and run the engine, it cuts out within seconds. This will force the engine to run directly on alternator power. That works fine on my carbureted generator with points ignition (which I recently started without a battery like this), but may cause EFI and computer problems from the spikey voltage in something more modern.
One issue is that the smart clamps will not close their protection relay unless they sense some battery voltage. Without that, they don't know whether or not your polarity is reversed. There is usually a hidden button to override this, but that then overrides all of the safeties, including the timeout that prevents you from burning up the battery (these have a VERY short thermal duty cycle), wires and clamps.
Another issue is that while it may run for long enough to spin the starter and run the engine, it cuts out within seconds. This will force the engine to run directly on alternator power. That works fine on my carbureted generator with points ignition (which I recently started without a battery like this), but may cause EFI and computer problems from the spikey voltage in something more modern.
PhysicsDude
Well-known member
Depends on how the lithium packs handle voltage spikes and current backflow.
Many of the cheaper packs just have a huge diode on the positive leg to only allow current to flow out of the pack, and not in. This means the pack won't really act as a voltage regulator, and may damage electronics and ECUs.
I will say I've used a jump pack as a battery for a few minutes at a time in a 2003 Corvette, and it worked just fine.
I think you're unlikely to damage the actual lithium ion pack, assuming the cars charging system works properly.
I say go for it.
Many of the cheaper packs just have a huge diode on the positive leg to only allow current to flow out of the pack, and not in. This means the pack won't really act as a voltage regulator, and may damage electronics and ECUs.
I will say I've used a jump pack as a battery for a few minutes at a time in a 2003 Corvette, and it worked just fine.
I think you're unlikely to damage the actual lithium ion pack, assuming the cars charging system works properly.
I say go for it.
kctyphoon
Banned
So driving the car with them attached would damage them?
Wouldn't advise this unless you were completely desperate. I ran my fathers Audi TT off a bigger older style pack when his alternator and then battery died.. got it home the last 2 miles and had to stop twice to let the pack bleed enough juice into the battery. Drove it home with the hood hanging over the jump pack that was connected to the battery.. I wouldn't REMOVE the battery and try that though..
wkndwarrior29
Well-known member
Those lightweight jump pack cables are not made to handle sustained current. I would be interested to hear if it works though.
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Ole Slewfoot
Well-known member
YOu can get lithium starting batteries, Braille makes some nice light ones.
theoldwizard1
Well-known member
You can get lithium starting batteries, Braille makes some nice light ones.
Those are likely lithium iron (LiFe). Most jump starter packs use lithium cobalt oxide (LiCoO2). Very different.
Wamsutta
Well-known member
How about disconnecting the jump pack from the car after the engine is running? Can the engine run off pure alternator power?
kctyphoon
Banned
The Lithium pack from HF is Lithium iron. Suppose to be a safer, more stable chemistry.
WhiffySpark
Well-known member
- Joined
- Oct 22, 2009
- Messages
- 6,252
No I wouldn’t. Too many stories of kabooms once the alternator starts charging it.
I might try it with a jnc jumpbox thiugh.
I might try it with a jnc jumpbox thiugh.
Wamsutta
Well-known member
That could fry some modules.
So that by that you mean the alternator wouldn't be able to provide the constant Amperage needed by the modules; or would it be the constant Voltage needed by the modules?
Was going to buy the HF model yesterday for $80+tax but turns out they won't take the 25% off coupon. Next choice is https://www.cloreautomotive.com/sku.php?id=556 I can get locally OTD for $105.
lafester
Well-known member
I've started and idled for awhile with a noco gb70. nice thick cables and the pack didn't even get warm. It was just a test for worst case scenario though in case I need to limp home (or to a cell signal) from the mountains. The electronics inside the vehicle were not too happy though as it did not provide a steady power supply.
So that by that you mean the alternator wouldn't be able to provide the constant Amperage needed by the modules; or would it be the constant Voltage needed by the modules?
More worried about voltage spikes. Most every owners manual I've read says not to disconnect the battery with the engine running.
Why not keep a smallish car battery on a tender that you could move from car to car as needed. A bit more work, but eliminates worries about jump packs or cables overheating.
I've got a conventional lead acid jump box I use but lugging around 20 pounds of lead on the bus or subway and then walking a half mile or more to pick up a car isn't much fun.