NEXPEAK NC215 15-Amp Battery Charger, Trickle Charger Car Battery Charger 12V 24V LiFePO4 Lead Acid Portable 9-Stage Smart Battery Maintainer w/Temp Compensation for Car Truck Lawn Mower Boat Marine

I've been turning wrenches for 65 years. Came of age with all kinds of "dumb" chargers of different voltage and amperage ratings. Further, I'm very well versed in electrical and electronic matters. The classic Schauer 2/10/50 amp, 6 or 12 volt charger. Also, of late, one of those not dumb, not smart chargers that display a percentage of charge on an analog meter and need some kind of voltage to kick it into gear. No good for powering 12V devices. See Harbor Fraught Cen-Tech. I got a new AGM battery for my car. It wasn't fully charged, so I put that Cen-Tech on and switched to AGM. Over the next several hours it went from something low to full and back and forth over and over. I finally took it off and measured the voltage after turning the headlamps on for 30 seconds. I don't recall the voltage, but it was only perhaps 80% of full. IF YOU DON'T KNOW THIS, YOU NEED TO: There's an excellent way of finding out a car battery's health by charging it, and then getting rid of what's called the "surface charge." Turn the lights on for a minute, or let it sit overnight. Measure the open circuit voltage. There are many charts on the intertubes that list voltage by tenths and the corresponding percentage of new it is. These are available for both regular flooded lead acid and AGM's. For instance in flooded batteries, 12.7V would be 100% good, 12.46V would be 80%, 12.2V 2 would be 50%, etc. AGM's have a higher voltage for the same percentage. Since my Cen-Tech was not doing things right, I perused all the charger options on here. The first thing that struck me was that the old dumb chargers were gone. The new generation fully smart, solid state, ones were capable of amazing things. No, no more 50 amp starter boost, but a lot of functions that claim to repair old sulphated batteries. I chose this particular unit because it had a 15A maximum capacities, most others at around $30 were only ten amps. Go for the gold, right?I was astounded how small it was, being the old school charger relic that I am. I hooked it up to my new AGM using the LiFePO setting. Their needs are the same. Charged it to 100%.Then I put it on the old battery that had a 25% capacity per the overnight voltage. It immediately went into "DE5" desulpherization mode, then proceed to do a charge. After ridding it of the surface charge, I got....12.7 volts. ":New" I then put another battery on it, a couple of years old, still in service. Same thing. Wowsers!After that, the voltage was 12.7. Like new. I had the same result on a third battery that was not as old as the first.I then went to "Repair," which uses that pulse current voodoo black magic. It did its thing for about 45 minutes per battery. It works. If I had bought and used this $30 charger on the old battery, I would not have spent $150 on a new one.Hearing of my results, my brother bought the same unit.

Battery was completely dead as the car had not been used for 5 months. The charger would not charge the battery. I switched to and used the “repair” mode on the battery charger. Left it on for many hours and then I switched it to charging mode. The battery charged fully and I was able to start and use the car. I actually ended up replacing the battery since it was 8 years old and I didn’t have confidence in the battery.

I've only used it twice so far, and only with LiFePO4 batteries, but so far it seems capable. It seemed to charge at advertised capacity and proper voltage. The battery wire seems a bit small to carry 15A at 12V for very long though, so watch out for wire heating on really large capacity batteries that take Max current for a long time.The fan is a bit loud, but not too bad, and better than having a device overheat. The battery clips seem relatively sturdy, at least compared to some.The display is easy to read. The range of temperatures that do "normal" charging is pretty narrow, as winter or summer modes trigger over a wide range. So not sure how that affects performance overall. It ran in Winter mode in my garage.The battery cable is very short - only about 18" - would like to see that a bit longer - maybe 4-6ft. I wish these devices had more flexible cable attachment options too. A large Anderson type connector with several pigtails with different battery connector options would be really useful.I wish it could "wake" a battery with BMS shut down. I have one or two batteries with BMS that I've had to "zap" after a discharge cycle.I will update my review again when I've had a chance to try it out in more situations.

So far, it’s great. I used it on my 2008 Ford Edge with no issues. Ford apparently designs battery cables/connectors with the thought that you’ll never need to jump or charge your battery. Needless to say I got the charger connected, within 2 hours of charging, I was ready to start it. A little difficult to read the screen in bright sunlight, but with a little moving (out of the sun) you should be able to read it.

I received this unit yesterday, somewhat skeptical given Amazon indicating the unit is returned often. However to my delight, this charger properly and dutifully charged up my Watt-cycle 100AH LiFeo4 battery without issue (I pre-charge batteries before installing them into my system). The large display is nice, and the configuration is easy and intuitive. Thus far, it has shown itself to be high value for money.

I had purchased another LiFEPO4 charger and it was a piece of junk I was hesitant to try another but needed something to safely charge my sons expensive trolling motor. This is amazing! Works perform ctly with multiple charging optionsCompact and easy to use. I would 100% reccomend this

Good price, on a versatile charger.

This product worked well for less than two months. I bought it for a battery tender. It says in the instructions that there is a button for this but is isn't to be found. It seems to go to tender mode on its own after a time. Anyway, after 5 weeks of being in "tender" (I think) mode, it started to make a loud humming noise. I am uncertain if it was trying to explode (?). It's too late to return it, so here is the review. I cannot trust it to use again.