XIMAKA 12V 40A DC to DC On-Board Battery Charger Fit for Multiple 12V AGM, Flooded, Gel, Sealed, Lithium-Iron Phosphate, and Lithium-ion Batteries, with 3-Stage Battery Charger for RVs, Boats, Yachts

Versus renogy:Unlike the renogy dc-dc charger I've tried that drains the car battery and the aux/lith battery you have to install both negative & positive cables with a switch and 50a relay; otherwise, it slowly drains your batteries. It's not documented but it drains via the negative cable.This unit works perfectly and I can hear a click when it turns on which I like.Con: The documents for wiring sucks and doesn't even mention to need the DC+ port to literally power on the charger.Suggested wiring for best results:Wiring a switch to the DC+ then to the aux battery, not to the ACC wire of your starter is key. So you can control when the unit is charging/powered at all.Wirirng LC+ in two options.1. With another switch then to the starter or ignition wire give you the two options for limited power of 20amps or 40amps when switch is on. So even when the car is off you can charge your aux batteries but not kill your car battery that starts the car, manually have to switch off of course. 2nd benefit is if you have a stock alternator 90a then you don't have to upgrade. Just run limited and when driving on the freeway hit the switch to max charge at near 30-40amps. I get 26a-30a with a 90a alternator. It's fine. Charges a dead lith 100ah to full in 4-5hrs.2. Not put a switch and wire LC+ directly to your aux batteries. Will permanently keep max limit of charger to 40a max. This is best if you have solar charging the aux batteries at the same time as the front car alternator.By wiring both a DC+ switch and a switch for LC+ will give you total control. If no sun for days you turn on both switches and get while parked 26amps when car is on (with stock 90a alternator). And while driving you get 36a-40a with a stronger alternator installed in your vehicle.Note: Amount of amps will be lower as the battery gets more full.Note2: add ANL 50a fuses and 4ga flexible wire on the positive wire for both input and output.

It pulls about 60amps from the alternator and puts in 40amps into my lifepo4 battery. Ignition switch is a plus, turns on when the vehicle starts and turns off when the vehicle shuts off, just make sure you connect a thin wire from the easy plugin connector next to the battery select knob to a 12v source that only turns on when they key is in, such as your radio. Compared to alternative dc chargers you can’t beat the price.

The 3-stage battery charging ensures that my battery is fully charged and ready for use at all times. I especially appreciate the fact that it is compatible with multiple types of batteries, including AGM, Flooded, Gel, Sealed, Lithium-Iron Phosphate, and Lithium-ion batteries. Additionally, the fact that it’s portable and lightweight makes it the perfect charger for use in RVs, boats, and yachts. The customer service provided by the XIMAKA team is also outstanding, as they promptly answered all my questions and made sure that I received my order in a timely manner. I highly recommend this charger to anyone looking to keep their battery fully charged and ready for use at all times.

Just when I really needed it, this thing failed on me.It stops charging after an hour or two, and then won't come back on for quite a while.

If I had known about D+ wiring requirement I would have bought a different product. I now realize that besides connecting between the starter bat and the house bat I also need to run another wire to somewhere, such as the fuse box, that energizes with the ignition switch. This adds another level of complexity to the installation I really wish I could have done without.