I came across a car with a dead 12v battery and didn’t want to use the 12v in my Lightning to jump it. I found an old battery tender (probably 20 years old) that had a ‘jump’ setting at 50A. Plugged it into my 110V outlet in the bed… and nothing. Now I’m wondering if there’s a way to jump a 12v battery using something that can plug directly into a 110V outlet without needing to charge a portable jump pack. I know there are a lot of jump starters out there, but I want something compact that works straight from my truck’s outlet.
I’d reconsider a portable jump starter. They’re pretty compact, hold a charge for months, and can jump both your Lightning’s 12V and other vehicles when needed.
Quinn said:
I’d reconsider a portable jump starter. They’re pretty compact, hold a charge for months, and can jump both your Lightning’s 12V and other vehicles when needed.
Yeah, this is the way to go. $120 well spent.
@Thorne
You can even find decent ones for under $50.
@Thorne
I got mine for about $70 at Costco. Works great, plus it doubles as a power bank for USB-C devices.
Quinn said:
I’d reconsider a portable jump starter. They’re pretty compact, hold a charge for months, and can jump both your Lightning’s 12V and other vehicles when needed.
I went overboard and got a Truck PAC ES6000 3000 Peak Amp 12V Jump Starter from NAPA. This thing can start a tractor or a semi—it’s got an 800CCA lead acid battery inside. It’s big and heavy, but I farm too, so it might actually come in handy one day. Stays in my frunk along with my adapters and extension cords. It cost me about $250-$300. Definitely not the lightest or cheapest option, but it works.
@Broderick
So now you have two lead acid batteries to maintain. Most jump starters these days use lithium instead.
Tatum said:
@Broderick
So now you have two lead acid batteries to maintain. Most jump starters these days use lithium instead.
Yeah, but I’ve got diesel equipment to maintain too. A 200A plug-in battery charger takes a while to get a starter going, but this gets the job done. Used it once on a 24V system with three 12V batteries, and it worked perfectly.
Quinn said:
I’d reconsider a portable jump starter. They’re pretty compact, hold a charge for months, and can jump both your Lightning’s 12V and other vehicles when needed.
Modern problems require modern solutions. This is the way. 
Last year, I was about to jump-start my Mustang from another car. A contractor saw me and said, ‘Let me show you how we do it in Mexico.’ He pulled out a DeWalt power tool battery and some frayed 16 AWG wire from his truck. Hooked it up to my car, told me to crank it, and… it worked. Super sketchy, but it got the job done. Just something to keep in mind.
This is why EVs need solar panels—not for the main battery, but as a 12V maintainer.
Ash said:
This is why EVs need solar panels—not for the main battery, but as a 12V maintainer.
Not just EVs… every vehicle should have one.
Ash said:
This is why EVs need solar panels—not for the main battery, but as a 12V maintainer.
Not just EVs… every vehicle should have one.
I’ve got a solar panel on my Jeep since I only drive it a few times a month. Keeps the battery topped off.
Ash said:
This is why EVs need solar panels—not for the main battery, but as a 12V maintainer.
Mount one like a Starlink dish.
You can’t just plug a 120V outlet into a car to jump it. A household outlet is only 20A, while a starter can pull 400A. Plus, you’d need to convert AC to DC.
Benn said:
You can’t just plug a 120V outlet into a car to jump it. A household outlet is only 20A, while a starter can pull 400A. Plus, you’d need to convert AC to DC.
400A at 12V is 40A at 120V—not impossible, but still twice what a standard outlet is rated for.
@Laken
I had a cheap Costco jump pack that wouldn’t even start my 6-cylinder BMW when fully charged. Got a Noco Boost 70 instead, and it works every time.
Benn said:
@Laken
I had a cheap Costco jump pack that wouldn’t even start my 6-cylinder BMW when fully charged. Got a Noco Boost 70 instead, and it works every time.
Was the Costco one lead-acid? Lithium jump packs should work.
@Laken
Nope, it was lithium—basically a large power bank. Still didn’t work. Returned it.
Benn said:
You can’t just plug a 120V outlet into a car to jump it. A household outlet is only 20A, while a starter can pull 400A. Plus, you’d need to convert AC to DC.
Mechanics use capacitor-based jump starters for big trucks. That might be an option.