LiTime 12V 40A DC to DC Battery Charger fit for 12V LiFePO4, Lead-Acid, SLA, Gel, AGM and Calcium Batteries. 3-Stage Charger for Wide Range Application, RVs, Boats and Yachts.

This unit is built well and functions great, seems very durable. Easy to use as well. I have this set up to charge house batteries on my work truck that’s hooked to an inverter. This extends the battery life of my house batteries by keeping them topped up and prevents my engine batteries from completely draining from the load of secondary electronics. This is a great price for how useful this unit is. I added a switch where it says to use the jumper wire so I can easily turn on and off the charger to my batteries. Would recommend.

Updated: This charger works well BUT should only be used on LiFePO4 batteries. It is not possible to get a temperature sensor and therefore it is not safe to use on any kind of lead-acid battery.I hooked this up in my travel trailer. The input is the old DC converter which I disconnected from the DC distribution panel and rewired into this DC-DC charger. The output goes to bus bars that in turn feed a pair of 100ah gel batteries. The runs are short, less than three feet and all made with 8 gauge wire. I discharged the batteries to about 80%, then started this to charging. With the 20 amp jumper installed it showed an initial charge rate of 18.5 amps. In a few minutes it was down to about 10 amps. I let it run overnight. The batteries are now at 13.5 volts and the charge rate is about 0.16 amps. The fan never came on and the unit did not get even warm to the touch.Taking off one star because of the temperature sensor problem.I contacted LiTime customer service through their web site to ask about a temperature sensor. They replied within 24 hours. After some conversation, they told me that the temperature sensor was not available and never would be. No other temperature sensor is known to work. Since I am using lead-acid batteries, the temperature sensor is critical to getting the charge voltages correct. They offered to refund the product. They sent me a return label. Within a week of me sending back the unit, they had credited my Amazon account. 5 stars for customer service.

I have installed all wiring with fuses to ensure nothing gets shorted and blows. No lights and no voltage. Looks good but zero performance. Didn't have time to check everything when it arrived but first power up and 0 volts that's a supplier who doesn't give a crap. Stay away!

I was upgrading a simple power bank, of (1)100ah LFP battery with a direct charge switch to the main battery, to a more robust system of (2) 200ah LFP batteries. The direct charge switch is no longer working for many reasons.The LFP can be charged/sucks a lot of current form the alternator; using a victron smart shunt, it showed 90amps running through at charging. It would be a burden even for a 220amp alternator. Also I would have to use charging wire larger than 4awg. Smart alternator voltage also fluctuates from 13.7-14.9, on its own, not depending on the stage of charging, making it unfavorable to charge LFP batteries.This Li Time 40a dc-dc charger gives a stable 14.6 volts, and 36.6amps at charging (92% efficiency vs 95% claimed). It manages to push my 400ah system to 14.4volts. It’s only warm to the touch after 4 hours plus charging my batteries; it’s not loud either, can’t hear it when the fan is on if not paying attention to it.So far, I am happy with it. I picked it in the first place since my batteries are Li Time as well( based on review from Will Prowss), and thought if Li Time can make good BMS for their batteries, then they can definitely make good dc-dc chargers.

I was impressed immediately with the build quality of the product as soon as I unboxed. The included instructions were good quality and easy to understand. Once installed in my portable power station, the charger worked exactly as expected. This is a very good quality unit at a great price. I would recommend.

I am impressed with the seemingly good build quality. I could not get this to function as when the engine was off or on in my class A motorhome the unit would switch from fault to charging every 2-3 seconds.

It charges well with the jumper setting to 20 amps but 40 amps the LED flashes as a fault.

been using it daily. i should have gotten a 100amp. still a good charge and adequate features. should by a switch for it to control from cabin. the product only has a small cable. as well, keep the air around it clear, as should be expected with these and is labeled in instructions. very good.edit: strange this review thinks it's a toy. this is not a toy. this is an ac\dc converter for battery charging. if you see this review under a toy. then it is mismarketed.