LOKITHOR J400 Portable Jump Starter, 12V 2000A Lithium Battery Booster with ConnectMax Tech, Car Jumper Box for Up to 8.0L Gas & 6.0L Diesel Engines, Smart Digital Display

SEE CONTINUED REVIEW UPDATES TOWARD END OF REVIEW,,,AS OF 5-2-26...WORKING GREAT!!! I have just got through using it twice to jump start a MF 135 diesel tractor that had an old /totally drained battery. It didn't stagger a bit and jumped the tractor within 1-1-1/2 seconds and did it in a powerful/strong/solid manner. This thing is really impressive and I just hope that it gives me this type of performance for an acceptable amount of time (i.e...long enough that I feel I got my moneys worth). As of now, I'd recommend it to all my friends/relatives. NOTE...the only "Ah Man" moment about the purchase was that within 1-2 days of receiving it, I saw that it had went on sale for 33% off the original price I paid $89.95...it dropped down $30.00 to $59.95. I really wish that the vendors (not necessarily Amazon) would honor the discount/sale price, especially if it goes down while the item is in transit to your delivery address. ============== 11-29-25 UPDATE...STILL WORKING GREAT...use it 2-3 times every two weeks to jump start the 1971 MF tractor with the Perkins diesel engine and it's still works like a champ!!! ============== 04-25-26 UPDATE (OVER A YEAR NOW)...STILL WORKING LIKE A CHAMP...I continue to use it 1-2 times every two weeks to jump start my Dad's 54 year old Massey Ferguson tractor (Perkins diesel engine). It has a battery that can't be charged and alternator that is not working. THIS PRODUCT IS ONE OF THE BEST BUYS GOD HAS BESSED ME WITH...funny thing is that I bought it to keep in my Harley Low Rider saddlebags.

I desperately needed a jump starter battery for a car I barely drive and was tired of having to trickle charge it all the time so I purchased this jump starter. Overall impression is this thing is powerful and easy to use right out the box. Once connected to the car battery it will automatically jump start and let you know when the car is ready to be started. This thing is very useful to have in your trunk for emergencies, highly recommended to everyone!

Bought this over the NOCO after seeing reviews and videos. I have a Viking jump pack at 1000a and it is more expensive than this unit. I have used the 1000a to jump all of our vehicles when needed, including my motorcycle and my lawn mower, so this unit shouldn't have any issues with anything I throw at it. Lightweight, compact and easily stores in your vehicle. Bought this to keep in my truck. I like being able to jump start the vehicle without needing another vehicle to use jumper cables. Keeps you self-sufficient and gets you out of a jam if you find yourself alone in a remote area. Charges quickly and doesn't lose charge over time like other traditional jump packs. Like other lithium jump packs, they do recommend that you charge the unit every three months to extend the life of the batteries in the unit. Pretty standard.

I’ve been using the LokiThor J400 for about a month now and I am genuinely blown away. In that short time, I’ve used it 2-3 times on my own 1997 Jeep Wrangler (Dealing with electrical issues.) Ive even helped two strangers get back on the road with dead batteries. This thing is a lifesaver — literally. This unit is barely larger than my hand. I expected something bulky and awkward, but it sits effortlessly in my glove box and weighs almost nothing. You can feel the quality in the weight. The connections are rock solid and the build quality is exceptional. No sketchy clamps, no questionable wiring — everything clicks into place with confidence. It's very straight forward, you plug in the positive & negative clamps and you're good to go. It fired up my Jeep every single time without hesitation. It is also a serious portable power bank. I’ve charged my phone multiple times on a single charge — it has more than enough juice to keep your devices powered up on long trips or during emergencies. Battery life is good. If you want compact size, reliable connectivity, genuine safety features, and ease of use all wrapped into one powerhouse device — this is it. Best purchase I’ve made all year. 10/10 would recommend to anyone who drives a car.

Build quality on this device is great and I took it apart as shown in photos and it is built well. It was able to jump start my motorcycle no issue although this battery is smaller so I would stick to 4 cylinder cars only. Build quality seems like it emphasizes safety as I can see what looks like a temperature probe on top of one of the pouch cells

Well made, works well. The zippered case is nice, but too small making it difficult to put the cables back in. Otherwise 5 stars.

I was really surprised at how small it was, considering it's features. Nice and rugged too! The USB port won't fast charge your phone, but will definitely do in a pinch. The flashlight function is pretty good as well, very bright and large. I loved the little lights it has for which terminal you've got connected, and the ability to check your battery's voltage is my favorite feature I haven't needed to use it yet (knock on wood), but it gives me some serious peace of mind knowing I have it.

This Lokithor J400 jump starter has already paid for itself because it saved me from being stranded by a dead battery. It is easy to use and easily starts my mid-size car battery. I can actually use it several times before it needs recharging. At least 4 or 5 times. Easy to apply and easy to charge with a USB charger. The flashlight also comes in handy in an emergency. It is also capable of charging a cell phone in an emergency. The cell phone charge rate is kind of slow compared to a standard ac charger but it does charge a cell phone. It was well worth the sale price that I got it at. I have already needed to use it for a jump start 4 or 5 times and it comes in handy especially when you are stranded.

Super