Car starter (dead battery) Lithium battery power bank

[lumen aeternum]

Ran my 3 year old car battery down to 6 volts in ACC mode - these new cars have TINY batteries!
Looking for a powerbank designed to start a dead car battery.
I have searched and not found many threads talking about this.
Anyone know how many years they should last before the batteries just deteriorate (even if kept charged) ?

Looked into the Ultracapacitor types, but it says a lot of cars electronics are programmed not to start below 8V. You have to jump thru some hoops in that case, disconnecting the POS lead & then reconnecting it while the charger is still connected to it -- and do it without grounding your other hand...

 

[turbodog]

With what sounds like a quite dead battery... I think you're gonna have a tough time jump starting it without letting it charge some first. The jump start current would be split between starting and simultaneously trying to charge the battery. Would take some serious power.

That said... I've had very good results from the noco brand of chargers. They also make jump boxes as well.

 

[lumen aeternum]

I think you're gonna have a tough time jump starting it without letting it charge some first.

No, the ultracap type takes low amperage charge from the low battery; if its not completely dead it just takes a few minutes. The the cap discharges 400 Amps to start the car. Once the car is running the alternator takes over.

 

[knucklegary]

I own Noco GBX75 2500a jump starter, power bank, emergency (8) LEDs 500lms with SOS beacon, which is really cool! Their boostX units incorporates a voltage bypass so you can jump dead batts at full juice. They're a bit pricey, but if you're a Leo/mil and veterans they offer a substantial discount

 

[turbodog]

You can't force amperage. It's a by product of voltage in the case of a fixed 12v system. With a battery at 6v... that's going to depress usable voltage to the starter significantly.

 

[Lynx_Arc]

Without knowing what size of motor in the car and what caused the battery to be discharged that low it is quite possible any barely adequate jump starter pack may struggle to both start, charge the dead battery, and also supply power to what is draining it at the same time. Personally I would even if you get it started make sure and find out what is draining it that heavily if it wasn't an accidentally leaving the lights on or something likely it will happen again and again. I had to replace a 4 year old battery recently that was at times struggling to start my car which has a 4L motor and when I got to where I was going and stopped it after driving for 25 minutes long enough to charge the battery up fully I stopped and decided I needed to park it in a better spot and found out it wouldn't restart the motor the battery finally gave up completely the old chattering solenoid sound. I think that the heat from in the mid to high 90s and running the AC in daytime in the sun with dark colored paint all cooked the battery to finally kill it.

IMO these jump starter packs should work decently on smaller 4 Cyl motors and vehicles that the battery tries to start the car but gives up after a short time but super dead batteries can cause a big load on them as instead of being able to help a little maybe taking 35% of the load of starting they subtract from the power of the starting. A starter dropping the voltage to 10-11V a battery that is not far below that range likely won't be an issue but 6V to me makes it a possible heavy load on the jump pack and as a load if the pack cannot maintain a high enough voltage to run in the range of the starter being more efficient it could drop below 11v to 9 or 10V and the starter if older may also need more power to accomplish starting the motor.

I've no experience with these jump packs at all but realize that to less powerful batteries a heavy load to them looks like a dead short and the voltage drops to nothing. If the pack monitors voltage out and has safety measures to cut off when the current gets too high you should be able to see if it will suffice or not.

 

[turbodog]

Did some reading on the cap-based units. They seem to work, and pretty well at that. But something seems strange there... maybe they are hitting the system with voltage well over 12v.

Reason I say this is because I use some custom-made welding cables myself. Even with a fully charged battery, they often require the target vehicle to charge for a few minutes before cranking. And I guarantee a welding cable can source more amperage than a 7 gauge jump box.

I'd like to get my hands on one of these for some testing... but I don't have any dead batteries for testing.

 

[turbodog]

I own Noco GBX75 2500a jump starter, power bank, emergency (8) LEDs 500lms with SOS beacon, which is really cool! Their boostX units incorporates a voltage bypass so you can jump dead batts at full juice. They're a bit pricey, but if you're a Leo/mil and veterans they offer a substantial discount

Wish noco made cap-based units, but their bread/butter is in chargers and lithium jump boxes.

 

[orbital]

+

A few years ago when Toyota was in LMP1 prototype racing , they used supercapacitors for their hybrid power unit.

 

[lumen aeternum]

IMO these jump starter packs should work decently on smaller 4 Cyl motors and vehicles that the battery tries to start the car but gives up after a short time but super dead batteries can cause a big load on them as instead of being able to help a little maybe taking 35% of the load of starting they subtract from the power of the starting. A starter dropping the voltage to 10-11V a battery that is not far below that range likely won't be an issue but 6V to me makes it a possible heavy load on the jump pack and as a load if the pack cannot maintain a high enough voltage to run in the range of the starter being more efficient it could drop below 11v to 9 or 10V and the starter if older may also need more power to accomplish starting the motor.

The SuperCap units start w/a completely dead battery by disconnecting the battery from the system, the reconnecting it once the car is running. Sounds like a shock hazard procedure to me, reconnecting it.

Wondering if the Lithium packs have the same procedure ?

 

[JLFORBES]

A car at work would not start so I borrowed a jumper unit that used a lead acid battery and cables. I tried over a half hour to get the car started however it didn't help and it actually left me with a battery that was so low at this point that it didn't even make the relay click. I went to the local NAPA store and bought one of these NAPA Blue Fuel 1000PA Jump Starter and Power Bank

I connected it directly to the car battery, turned on the device, and turned the key. The car started immediately to my surprise because I was expecting it to take at least a few minutes to get the car battery to take somewhat of a charge from the power pack.

I'm here in Miami and i usually change out my car batteries after 3 years in service.

 

[tyoda0202]

Also have a NOCO jump starter, has worked fine on a 6 cyl Acura MDX and Toyota RAV4, but had a hard time with a 2006 BMW X3. Not sure if it was because the battery configuration for BMW's with battery the rear trunk/cargo, separate from engine compartment?

Check on YouTube, there's several folks reviewing portable car battery chargers. There are many other brands to consider, some less known, and not as well advertised as NOCO.

 

[Lynx_Arc]

The SuperCap units start w/a completely dead battery by disconnecting the battery from the system, the reconnecting it once the car is running. Sounds like a shock hazard procedure to me, reconnecting it.

Wondering if the Lithium packs have the same procedure ?

Not a huge shock hazard as 12vdc if your hands are dry and clean your skins resistance is usually high enough not a lot of current will pass if any. This idea doesn't sound like a portable device but rather a permanent solution as disconnecting and reconnecting a battery isn't something quickly and easily done I wouldn't want to do it often for fear of accidentally damaging the battery terminals somehow rendering it useless for starting a vehicle.
One issue I see is having an electrical system running off the alternator with no battery then essentially putting almost a short on it with a dead battery in an instant that could cause damage perhaps to the voltage regulator or alternator diodes even. I've damaged my charging system jump starting cars back in the day I was working at a parking lot by cars with a flaky electrical system I guess so when I repaired my charging system with a new voltage regulator and alternator I would remove one terminal of the battery to jump start but back then there was no memory in electronics at all so wasn't a big issue.

 

[turbodog]

The SuperCap units start w/a completely dead battery by disconnecting the battery from the system, the reconnecting it once the car is running. Sounds like a shock hazard procedure to me, reconnecting it.

Wondering if the Lithium packs have the same procedure ?

No shock hazard. However, a (modern) car that's running with NO battery (or equivalent) in the system.... is a big 'no no' as there's nothing there to absorb voltage spikes.

From my further research into the cap-packs... at least some of them, when 'armed', sense the starter's activation and only then enable their output, thereby making the most of a very limited amount of charge. Some fairly good engineering at play here.

 

[turbodog]

...back then there was no memory in electronics at all so wasn't a big issue.

Yes. A battery disconnect costs me around an even $100 to get stuff reprogrammed. That's not counting the radio code and station presets either.

 

[Lynx_Arc]

Yes. A battery disconnect costs me around an even $100 to get stuff reprogrammed. That's not counting the radio code and station presets either.

I guess I'm lucky as the Kenwood car stereo I bought a few years ago only forgets the time and date when power is removed. I do have to reset my alarm though. I recall one time my car stereo quit working and my car wouldn't start and traced it down to a loose accessory power connection to the battery.

 

[knucklegary]

No batt disconnect with lithium jump starters

Noco Boost X can hook up as power source when exchanging batteries eliminating the need for reprogramming

Also works with all 12v including AGM which I am currently running in my vehicles

 

[lumen aeternum]

There are 9v battery dongles that connect to the OBTII port as well, some people say they can harm the electronics.

Seems to me that better engineering would be to have the "electronics" on a separate battery, which is charged via the main system, with circuitry to shield it from spikes on the "car" battery.

 

[turbodog]

As long as battery is present, there are no spikes. It acts, even when discharged, as a filter/capacitor/buffer from those.

 

[orbital]

+

Thanks for the heads up on 'need to reprogram' issue.
If I ever replace the battery on my 2017 Santa Fe, I'll clamp a 3 cell (12~13V) to it in the interim to act as a UPS.

________________________
Any jumper unit that says it's Li-Ion has to have caps/something to give the initial thrust to the system jump. A number of 18650s' are not going to turn over a larger engine, there has to be more magic going on.

Love to see a couple of the better jumper insides to see what makes them tic.....