Lithium LiFePO4 Car Battery Auto Battery, 12V 40Ah, 660CCA, 100RC Deep Cycle Start and Stop Car Batteries, IP66 Waterproof, H5 H6 H7 Automotive Replacement Battery for Cars, Trucks
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Features
- Tip: To Extend The Service Life Of The Battery, We Recommend That You Fully Charge It Before The First Use. This car battery is suitable for vehicles with an engine displacement below 2.0L. If you are unsure whether this car battery is compatible with your vehicle model, please contact us for assistance.
- Compact Size&Strong PowerOur 12V 40Ah start-stop car battery measures 9.5x6.9x8in and weighs 14.8 pounds. IP66 waterproof ensures you to use lithium batteries anywhere safely. This car battery originally had threaded terminals. For compatibility with more vehicle models, we've added M8 screws to the battery pack. You can install an M8 screw on the negative terminal. The screw height is 30mm(1.18in)when installed, it will increase the total battery height to 9.18in. Please verify this dimension fits your vehicle.
- Good Replacement for Lead-acid BatteryThe lithium car battery is the good replacement to lead-acid batteries. It has a longer service life, deeper cycle times, higher energy density and is maintenance-free. This auto battery is equipped with a BMS protection, which can better protect automotive battery to prevent over charge, over discharge, over load, over voltage, over current, over heating and short circuit,ensure the health of the battery.
- Excellent Performance of LiFePO4 Automotive BatteryThe 12V 40Ah automotive replacement batteries feature 100RC and 660CCA performance, ensuring immediate ignition even in extreme temperatures. Charge:32F-113F(0C-45C) Discharge: -40F-140F(-20C-60C) Storage: 32F-113F(0C-45C). Our car batteries are equipped with a battery heating process. When the temperature is extremely low, the BMS will warm up the battery to ensure its discharge performance at low temperatures and extend its service life.
- NO Heavy Metals&Strong StabilityOur auto battery products do not contain any lead, chromium heavy metals, it has higher energy efficiency, longer service life and also reduce CO2 emissions. This is very helpful for the improvement of the environment.
- Emergency Battery Restartlf the battery is fully drained and won't turn on, you can press the white button to force-activate it in emergencies.
- Professional After-sales ServiceWe are professional lithium battery manufacturer, we have a large R&D department and after-sales service team, if you have any questions, we can provide you with technical support and rapid response of after-sales service.
Brand: ECIENWELL
Vehicle Service Type: Passenger Car
Size: 12V 40Ah
Automotive Fit Type: Universal Fit
Manufacturer: ECIENWELL
Number of Items: 1
Compatible with Vehicle Type: Passenger Car
Automotive Fit Type: Universal Fit
Size: 12V 40Ah
Brand Name: ECIENWELL
Manufacturer Part Number: A1240
Model Number: ECW-A1240
Manufacturer: ECIENWELL
Manufacturer Warranty Description: Technical Support&10 Years Manufacturer
Included Components: 12V 40Ah Automotive Battery
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This item is non-returnable:
Non-returnable. Transportation of this item is subject to hazardous materials regulation
View our full returns policy here.
Non-returnable. Transportation of this item is subject to hazardous materials regulation
View our full returns policy here.
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Top Amazon Reviews
Size: 12V 40Ah
I purchased this for my 94 Jeep Wrangler. The positive and negative were on opposite sides from the original battery. That wasn't difficult to remedy. The battery had enough charge to start the engine as delivered. Have not had a single issue with it. Worked in freezing temperatures. So far, I am very impressed. Best battery for the money.
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Reviewed in the United States on March 17, 2026 by richard miller
Size: 12V 40Ah
Well, it is now time to report back. I tried two different super capacitor banks, one with 8 guage wire, and a smaller one with 14 or something. Both helped, but burned up eventually, so something is weird. I then just got a real, automotive capacitor- the ones for audio. And it did help in making my equipment work properly and stop the lights flickering.... I would mention that it would turn itself off frequently for apparently no reason- I'd have to press the button on it to keep turning it back on almost every morning. I'd say just avoid and loook at the WEIZE batteries if you have a size constraint. Except now, 2 or 3 months later, it left me stranded for the last time. It's dead. RIP. No voltage across the terminals. BMS must have burned out, who knows. How bizarre. Old review: Unsure just yet. Put it in my 2009 Saturn Sky. At first it cranked but refused to start. Eventually I got it to start, and now it starts reliably- but the lights flicker at idle and radio pops occasionally. Very strange, I imagine the BMS is unstable with switching between charge and discharge states, and the voltage bounces from 12 to 14 quickly- checked with an oscilloscope. For this price- its unbeatable, and seems good. Might attempt a 16v super capacitor in parallel, and see if that smoothes out the voltage. If so, I'll report back. :)
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Reviewed in the United States on December 2, 2025 by Amazon Customer
Size: 12V 40Ah
Using to start a old tractor and a 11kw diesel generator. You can't crank long before it shuts down. it resets after a bit and you can try starting again. If your engine doesn't start easy you won't like this battery. Bought a third one for my mower.
Reviewed in the United States on March 4, 2026 by Tim
Size: 12V 40Ah
Great little battery. I installed it in a trailer to run the electric lift and a winch. Seems to work great, does not seem lose charge like the lead acid batteries and is very light.
Reviewed in the United States on November 24, 2025 by hogner
Size: 12V 40Ah
Would have loved to used this battery but because of the emergency button sticking out the top it would not allow my computer stuff to seat correctly, not to mention a m8 screw on the negative terminal, it's a great and affordable battery I'm sure but just would not work for my 2021 jeep compass
Reviewed in the United States on January 9, 2026 by Not as "fluffy" or plush as the description or picture shows, and not nearly as long either unfortunately. I was really looking forward to it but will be returning it for the price paid for it, it's just not quality material.
Size: 12V 40Ah
The media could not be loaded. A little glitchy but does work in some makes and models. Other makes and models maybe not. I've purchased 4 of these batteries to test out on various makes of vehicles. I can say that these do work in my 2023 Subaru Solterra, 2014 Subaru Crosstrek hybrid and 2005 Jeep Wrangler. I first tried this battery in my Solterra EV as a replacement for the problematic OEM lead acid that functions as the accessory battery. It worked flawlessly. I then installed it in my 2005 Jeep Wrangler as the starter battery. It worked but causes some weirdness with the electronics. After starting the dash flickers like the battery is dropping out periodically. This is tolerable but I'm not sure what it means for battery longevity. And then I installed this as the starter battery in my 2014 Crosstrek. I saw no issues there. Finally I installed it as an accessory battery in the Crosstrek which is unique to the hybrid Crosstrek. So far it has worked. All said, I have had to swap one of the batteries from the Crosstrek to the Jeep because the Jeep did not like how glitchy one of the batteries was. So there are differences between the same model of batteries. Others reviewers have noted that it caused issues with their car's electronics and I believe that having seen how glitchy this battery can be. So do your research before buying. It's just for my cars (models listed) it seemed to work out. Additionaly, I have also done some testing on the bench with this battery. I measured the capacity and it came in under the rated 40 amp-hours at around 25 amp-hours at 80 percent depth of discharge for me. I have photos of installations attached. Additional notes, for the Crosstrek starter battery I had to add about 3/4 inch under the battery to bring it to height as the cables didn't have much compliance and the OEM battery is taller I also had to move one of my hold down rods on the Crosstrek to avoid the hold down from interfering with the button on the top of this battery. If you look closely as the video uploaded from my Jeep you will note that the dash lights flicker just after start. This is most notable when viewing the odometer. The flicker is not supposed to happen. One final note I'd make for folks is I live in a very mild climate as my winter rarely fall much below freezing. If I were in a colder climate where winters frequently dip below 32F I would not recommend installing this battery as a replacement for your lead acid. Overall I do recommend this for those in warmer climates as long as your model isn't listed in another review as being problematic. I'll update this review if I encounter longevity issues.
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Reviewed in the United States on December 28, 2025 by Lazyreviews
Size: 12V 40Ah
Works for my Smart Fortwo 451. Replaced a Lead Acid H5 battery and this LiFePo4 battery is 21 lbs lighter and fits great! The Smart Fortwo ECU + SAM computer has no problem with this battery and the higher resting voltage. Everything works great except this battery will have 13.3V resting voltage. If you have a automatic day light running light with a 13v voltage cutoff relay it will not go off, because now you have 13.3V resting Voltage instead of 12.8V! Besides this the battery works great. Maybe there will be a problem for people who need a regular minus pole, it will raise the height by 1.5 inches. Wasn't a problem for me since my minus pole is fixed with a 8mm screw. The battery was delivered not fully charged. To charge it you would need a 14.6v charger with a max of 8 amp. You have to press the knob on top first or it will not charge after delivery. After the first charging the battery works without any problems. Starting power is great since the resting voltage is 13.3 volts...
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Reviewed in the United States on October 26, 2025 by Christian Dahlmann
Size: 12V 40Ah
Where to begin... this is better in every way!, less than 1/2 the price than a lead acid battery, also 1/2 the weight, no maintenance! And delivered! Truly plug and play. And a life span that's absolutely unheard of!!! It's now 3 days later, my cruise control wouldn't set, and my electronic AWD quit working. Put a new lead acid battery in, and all the problems went away.
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Reviewed in the United States on September 25, 2025 by Kurt