12V 40A DC-DC Battery Charger with MPPT Solar Controller, Dual Input Smart Charger for 14.6V LiFePO4 Lithium Batteries, Fast Charging for RVs, Campers, Trailers, Solar, Home Backup and Off-Grid

I have been using this 40amp DC-DC charger for 10 months now and it has been great. Works like it should and has been trouble free. I dont use solar so I cant judge that and I havent yet used the reverse charging so I dont know about that but I really hope that feature works. I have a 300amp alternator and a 300 amp hr battery. I like it very much

Connected this to my truck battery with fused 4 gauge cable. Used 2 gauge cables to the parallel 100ah batteries which power my 1500W sine wave inverter. Used breakers between connections for safety and peace of mind. I charge the battery bank while driving. **One caveat: this LiTime 40A dc-dc charger gets very HOT**. I now aim a fan at it while driving/charging my battery bank to help cool it. It charges my batteries very quickly and has gotten me out of a pickle while out camping with very little sun/solar availability! This system is now self-contained as long as I can run the truck engine. I have all the comforts of my home kitchen including fridge, microwave, toaster, instant pot, induction cooktop; cabin heater, air filters, electric blankets and heating pads. A true “glamping” experience!

You can't run this in 40 Amp mode. Mine barely worked in 20 Amp mode. It cycled off and on a lot (red light error) even with 6 foot wires from my Aux RV Battery. It may have charged my LifePO4 batteries 50% of the time. LiTime customer service did let me ship it back to them and gave me a full refund though which is good. I just think this is one of their poor products. I use their LifePO4 batteries which are great!

I’ve bought many LiTime products in the past and have been very pleased with their quality, reliability, and performance. I should’ve read the specifications more closely before purchasing it. After receiving it, I realized that it is limited to a solar panel Voc of 26V. Most panels are substantially higher than this making this unit not very useful to me as a MPPT controller. Yes, the Voc limit is indicated in the specifications way down the page, but considering that the Voc is as low as it is, the manufacturer should do a better job of stating this more prominently. Anybody that’s moving 40A around to charge and recharge batteries is probably going to be using panels with a Voc of at least 30 to 40 V. Because of the need to protect against high Voc on a cold day with full batteries, I would expect a 40A MPPT controller would have a max Voc of at least 50 V. Nonetheless, because I did not read the specifications more closely and I was in a hurry to get my DC to DC battery charger installed, I’ve decided to keep the unit and hope to find one or more panels in the future that have a low enough Voc that I can use them as well. UPDATE LiTime contacted me after I posted this review and offered me a full refund if I was not completely satisfied. This is an example of the kind of excellent customer service I have experienced from LiTime in the past. Because it was basically my error not to be more diligent when purchasing this, I have updated my review to soften my criticism and I have decided to raise my review from 3 to 4 stars. This was my decision alone and LiTime did not pressure me to do this in any way. The unit I purchased is exactly what was advertised and performs well doing the most important function than I needed: DC to DC charging. Just make sure that if you plan to use this as an MPPT controller that you have panels with a Voc of not much over 20V, otherwise you risk damaging the MPPT controller on a cold sunny day.

Es muy bueno

Amazing device. It was so nice to put solar and alternator through one device. Very small considering what the competition looks like. I've only been using it a few days but it's performed perfectly on both alternator and solar so far. I do wish it had some monitoring capability either through an integrated Bluetooth device or a module like renogy but there are other ways to monitor.

would be nice if it had easy to access switches for on/off and 30/60amp modes. fan is mid level loud. works after 3-4 months so far. no directions explaining how to setup ignition on off start up.. was hard to figure out that.

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.