PowerMax PM4 100A Power Converter 110V AC to 12V DC | 100 Amp with Built-in 4-Stage Smart Battery Charger | Reverse Polarity, Overload & Thermal Protection | Ideal for RV, Boat & Off-Grid Systems

Product works as it should. No problems so far!

This is a solid charger! Its a bit heavy, but its not something you'd probably take on a hike anyway! You mount it, wire it, and let it do its thing. Anyway, I am running 4x 100 Amp Hour lithium LiFePO4 batteries off grid, and charging on bad solar day used to take forever. If you have 400 amp hours worth of batteries, your 15 amp charger will have you burning way to much fuel on your generator. But at 100 amps, an hour of charge will sometimes be enough to run the day. Way better! Anyway, I tried to post a link to my YouTube video but Amazon didn't allow that, but you you want, go look for my name on YouTube and you'll find it. Otherwise, I did see an honest 100 amps of charge, measured with my clamp on amp meter multimeter. I'm totally stoked to finally have this online and working!

This item is a few years old now and have not had any problems with it operation since day of purchase. The item is of good quality and dependable.

SWEET DEALS! Works great, EZ installation and better power distribution for 1999 FLEETWOOD BOUNDER 28T. Although you must installation the wire harness bundle from the box roof, pull down some extra wire and mount it on the box floor, maybe on a wood plank.

In our modern day world today this company stands out as number one for sincere customer service, caring attitude and user friendly service toward analyzing and correcting any situation. Businesses like Powermax need to be rewarded for excellent integrity, including qualities and characteristics that are difficult to find these days. Before purchase i called Powermax to inquire about installation and all questions were answered completely and professionally. I then purchased two 100 amp Powermax PM4 units to install in my live aboard Yacht. The unit worked perfectly. Along the way a problem developed so a phone call quickly solved the issue. Another situation occurred with the charging because of the large size battery bank onboard the Yacht. It was explained that these units are more designed for a smaller battery bank. The tech support of this company is beyond excellence for their professionalism, patience , understanding, and eagerness to make it right. Multiple conversations with Conner and Errin of tech support were fulfilling and educational. The situation was critical because at anchor in the middle of nowhere the refrigerators and other important equipment need continual power. The tension was increasing in a very stressful situation. Then without asking the tech department offered to send me two replacement units. I quickly received email confirmation that they were shipped fed ex the same day. Now, that’s a company that deserves recognition!!

Using this unit to power Car Audio Amplifiers in my room. For everyone else thinking of buying for the same reason, DONT BUY THE CHEAP $30 CHINESE POWER SUPPLIES!!!! The cheap Chinese ones have loud and obnoxious fans, and I believe this one has a fan too but you won't ever notice it turn on unless you're using it in very warm conditions. This monster unit gets warm but never too hot to have any concern. I've had it for more than 6 months and is still proven reliable for my use. It's not a cheap unit but you will be happy you went with this option. IT MAKES MY SPEAKERS SCREAM SND SUBWOOFERS ROAR!

First of all, the instructions were very poorly written. It talked about dialing in the unit to your specific settings desired. The default it came at attempted to charge my batteries at 13.6 volts and that won't fully charge them. So I followed the instructions and turned the screw it indicated while watching the output voltage on my meter. I wanted charging voltage of 14.4 and maintenance voltage of 13.4. So I began turning the Philips adjustment screw and instantly the voltage jumped to 16.6 and would not dial back down no matter how much I tried. Within 10 minutes my batteries started to boil and vigorously gas. A 100 amps at 16.6 will permanently kill your batteries within a couple of hours. I switched it back to default and off of custom settings, but still it only had one voltage output, 16.6. Now the unit was no good for me. So I returned it and bought a IOTA DLS-90 Converter and Charger instead. The IOTA DLS-90 Converter and Charger with the IQ3, have been working flawlessly now for 4 months. It charges at 14.4 and maintains at 13.5. That's the default settings of the IQ4 and it didn't need any adjusting. Perfect.

It is unimaginable that this little thing puts out 100 amps. It is the size of a large cigar box and a tiny bit the size of my 2, count 'em 2 big 50 amp chargers previously. It will sample your battery buss and ramp up to voltage needed for charge "bulk-maintenance-trickle" 3 stage.When I connected my 8 golf cart battery bank I watched the buss voltage on my inverter ramp up to 14.6 and the 2 gauge wire I connected from this charger to the buss got a tiny bit warm. Huge amperage. I bought it for rapid recharge of the battery bank from either my Kohler industrial standby power plant, or my Honda 2000 portable generator. There was a lightning strike induced substation outage recently and I used my battery bank for a couple hours and then ran this charger off the Honda 2000 and the Honda was definitely under heavy load from this unit. The fans will come on soon after a full load and it keeps cranking out the amps. Seems to be a very good unit and being an electrical engineer, I don't see how it puts out this kind of current from such a small form factor.

Bought this to charge 4 very large 835amp Surrette batteries in 12 volt. I charge them when we have excess power from our off grid solar system, and then use the power when it's cloudy to give my hydroponic plants light. It works good. A word of caution this charger uses 15 amps right on the nose. It might be wise to put in an outlet and breaker that is 20 amps so that it doesn't trip on you. I've had that happen a couple of times. It seems to be on a 30 minute timer for max charge and then eases down. Uses 1800 watts for the first 30 minutes and then around 1500 (IIRC) watts after that for charging. I used 4 AWG cable for the 12 volt portion. Cable gets a little warm but not uncomfortably warm to the touch. The inlet cable (120 volt) doesn't get warm either. I suppose the fan is a little loud but I'm sure my plants don't mind the noise. Not even much heat leaving the charger with the fan on.

I replaced mine in my camper and I have been using those throughout the winter and it has been installed and charging my camper batteries for 3 months straight. A friend of mine also has it installed in his camper and it has been working non-stop for the past year. I am very content with this product. Hopefully it will last me a long time.

tl;dr Stable fixed-voltage mode. Well made internals. Loud fan that can be replaced with a quieter one. Screw terminals won't accept larger than 4AWG wire. I'm using it as a fixed-voltage power supply in my workshop, and as such have not tested the "smart charger" aspect. Having to work around the unit, the fan can get quite annoying as it's loud and on 80% of the time. Replacing the 80mm 12v fan with a quieter Noctua one fixed that. I'm honestly surprised at how stable the voltage output is. After setting it to 13.75v and placing a 700w load on it, the voltage only fluctuates between 13.70v-13.75v which is really nice. The only downside is the screw terminal outputs as they're quite small and won't accept anything larger than 4AWG wire. I would have preferred to see nut/bolt style terminals for lugs, but either way I ended up cutting a chunk out of 1/0AWG lugs to make my cables fit (as seen in my attached picture). I'll update my review if there's any lifespan issues, but otherwise I'd definitely buy another one considering the price.

See update below if you plan on running this at full power. This is an ADJUSTABLE 13.2v~16.5v DC converter with a built-in 3 stages charger. This means that the output voltage in fixed mode can be adjusted using a #1 Phillips screwdriver to turn the potentiometer and this adjustment will also be applied to the charging mode output (bulk will be increased or decreased and the other charging steps will be increased or decreased by the same amount). This might seems like an ordinary thing, however if using 6v deep cycle lead acid batteries such as the GC2 type from Trojan, USBattery, etc, which requires a 14.8v (for a 12v configuration) charging voltage at 25°C ambiant and then a significant increase/decrease in charging voltage as the battery temperate moves away from 25°C ( such as requiring 15.25v of charge at 10°C and 15.4v at 5°C), there aren't any marine or stand alone battery chargers out there (beside the expensive and short living inverter chargers or some solar controller) that can match those charging requirements. This converter is the perfect match to provide an accurate charge voltage and offer almost enough output (80a out of an ideal 120a) to match the charging power of a 900ah battery bank (4 parallel strings of 2 series 6v batteries) giving up to 20a of charge per string and since you can adjust the output voltage freely, it is possible to compensate for voltage drop in case your cable run is either too long or undersized, and then to also perform equalizing by being able to pump the voltage up to 16.5v under load (my batteries needs 16.2v at 25°C, and 16.55v at 10°C). Now the little downsides or improvements would benefit are : A 5/16-18 power stud instead of a mechanical set-screw lug would go a long way into making installation faster, more secure, sealed and versatile, as the lugs are barely big enough to take a 2 AWG fine stranded type 3 wire (takes a lot of patience to fit the cable without strands catching and sticking out) and that so the sake of voltage drop at such high amp, one would be expecting to use at least 3 AWG and up. Then being able to make a bolted connection with sturdy cable lug and sealed heat shrink is much more reliable than exposed strands molested by a sets crew in a marine or vehicule environment. A power on/off switch on the unit would be great too to prevent sparking or arcing when plugging the unit under load as well as leaving it plugged when not operating. The potentiometer adjustment is very sensitive, having a slower moving range would make adjustment much more faster (for temperature compensation when charging). Regardless, this unit is well priced and the staff at PowerMax were very helpful over the phone in answering technical question about their product prior to purchasing. I hope the build quality will be enough to last a few years, without any long term expectations. Upon inspection of the inside, thermal paste and wicking screw glue where used most everywhere. The temperature controlled fan moves enough air to keep the unit from burning up. Update on January 2nd : after running down my house batteries to about 50% capacity during the holiday parties on the yatch, I proceeded to charge them back and ultimately equalize them only to find out that the converter won't output more than 80a even when the batteries could be using over 120a of charging current. That being said, I was using a 15.4v fixed output and I suspect that the 100a output rating is limited to the 13.6v nominal rating as there is no other indications or rating available on the unit or the included owner manual. Even more, there are no input power ratings other than 110v-130v AC. No mention of nominal power or current rating. Further more, and maybe this has to do with using a standard generator to power the unit with 115v AC 60Hz and not a generator inverter that provides a cleaner sine wave 60Hz, but the converter was pulling 15a and more when running at full capacity, and for an extended period of time (several hours). And despite pulling almost 1 800w from my genset, I was barely getting 1 200w out of the unit. That's over 500w of heat and apparent power that the unit is wasting. The power factor of this converter is most likely low and could use a capacitor to rectify it's power consumption, but what has me worried is the undersized wiring on both input and output, as both ends were dissipating a lot of heat during normal use (using a Flir E8+ Thermal imager). This unit should be made with a 12gauge power cord and 20a plug or at least require hardwiring since a standard 15a receptacle (especially a gfci one) will produce a lot of heat. Same thing for the DC output, even though 2 gauge wire with a 105° rating is good for up to 200a when not bundled and below 30° ambiant, it will heat up to 10° above ambiant and that's the best case scenario. So once again, this 100a converter should have accommodations to use much bigger wiring. Lastly, the fan blowing hot air directly on the output cables sure doesn't help, but can be addressed with a simple deflector shield along the cable. If uou plan on running this unit at full output for more than a few minutes, definitively hardwire it with 12gauge on a 20a breaker to stay within the 80% duty (federal law) and be careful about your DC cables overheating when they run trough walls or doesn't have a 1" clearance around them (like running them together or in between equipment/structures). And you will need to have forced air movement of mounting inside a cabinet or where air cannot be renewed easily, as this converter will generate a lot of heat (enough to raise a 30"x30" open top cabinet to 30° C above ambiant). Another update from November 2020, while charging my batteries, about 30 minutes into the process, cold burnt plastic smell. Little investigation revealed that one of the four 40a dc fuse overheated in its holder and broke in two, leaving the other 3 fuses to take the full load and ultimately also melting them slightly. I was able to replace 3 fuses but the fourth one will need a new holder as the blades are properly stuck into the jaws, probably with molten plastic. Emailed the company with pictures, never heard back from them to this day over a month later. Haven't had the chance to open up the charger to see exactly what failed, but so far everything still works on only three 35a fuses. I was not expecting the unit to fail in such a way. Bottom line, I was expecting an advertised 100a output and a compliant max input power, so it's a fluke on both ends, but the unit does appear to operate properly in term of holding a steady output voltage and cooling itself even under max load for several hours. I was hoping to get the batteries recharged much faster, but it looks like I'll have to get another 100a unit in parallel if I want to achieve a steady 120a output without having the power input overheating. This knock a star off my initial review since it didn't not perform as advertised or at least from the few specs available.

This is a great product. I purchased one a year ago that's still working like new. I purchased a second one last month. I'll be buying a few more in the next year. I am using them to power a 12v DC stereo system I have set up in my workshop.