Powermax 110 Volt to 12 Volt DC Power Supply Converter Charger for Rv Pm3-55 (55 Amp)

I used this unit to replace an 80 AMP Intellicharger in a 40 5th wheel travel trailer/toy hauler that is in year round use. The unit replaced had been severely damaged by a mysterious power surge on the 120v AC input along with several other appliances in the trailer. It is working perfectly and having no trouble doing what its supposed to do. If the Trailer were not on nearly continuous AC shore power I might have gone with a higher output PS/charger but this one does just fine at less than half the cost of the unit it replaced. I reserved one star in my rating because who knows how long it will last.

It fit

So far, soo good. Its been running 24/7 for a month now with no glitches. The original unit in my RV was not keeping up with the demand of the two furnace motors and its been very cold. The reliability of the unit over the long haul is yet to be verified, hence the 4 stars.

Installed in my toy hualer works great. Definitely a upgrade from the old one.

Make sure you hook the blue wire back up if it’s a replacement for RV!

Install was easy. Mounting holes were same spacing but 1/2” wider then old one. No biggie. You do hear the fan kick on and off if all is quiet in motor home. (But how often is that). The fan should allow for longevity. I like the constant even voltage, and keeping my batteries charged. It does still work if battery is removed.

This was purchased to replace a single-stage charger/power supply in an older travel trailer. The older units bulk charge only design apparently contributed to shortening the lifespans of several (ruinously expensive) deep cycle batteries, something I didnt want to see repeated. This units three-stage charging should help address that issue. This unit was of slightly different dimensions than its open-deck predecessor, necessitating some engineering of the plastic enclosure, but that was known at purchase, and was not an issue. The fan-noise is quite reasonable, and is only active when needed. While I didnt open the unit to see its contents, the good quality of the metal case and exterior connections leads me to believe the the same quality is present electronically, an opinion supported by solid output voltage/amperage over two weeks of initial use.

Works like a Champ on our RV

The PowerMax PM3-55 worked well on the bench and charged my new AGM batteries. I like the fact that the voltage is adjustable. There is a tiny switch that lets you adjust a fixed voltage (set with a small trimpot next to the switch). Important note: The adjustment affects the voltages on either setting of the switch (including the normal setting which affects the voltages during the 3 stages of charging; Bulk, Absorption, and Float), but either way the adjustability is a plus ! The unit did not quite fit (as an exact replacement for the WF-8955 Converter/Charger) in my sons RV (very close though, and probably could have made it work with slight modification). Since this was intended as an upgrade (and the original was still working), we decided to leave well enough alone and leave the original in place. In any case, Im sure I will be able to make use of it as a nice charger for my car batteries when needed.

Took a minute to delete a power change switch. (Deleted switch).