PowerMax PM3-55LK
#4 in StandaloneFull review
A low cost standalone converter for owners who are comfortable setting a charge voltage by hand. A common budget replacement for a WFCO 9855 class unit.
Amazon $137$137
The PowerMax PM3-55LK rates 3.6 among standalone RV converter chargers; the Progressive Dynamics PD4060CSV rates 3.2 among panel and drop-in ones. The PowerMax PM3-55LK costs $115.73 less ($137 vs $252.73).
Progressive Dynamics PD4060CSV
The direct fix for a failed converter in a PD4060 power center, or a step up from a 45 A section.
Amazon $252.73$252.73
Prices were last checked November 2, 2026 and are subject to change; the price and availability shown by the retailer at the time of purchase apply.
Scores side by side
These two sit in different build classes (standalone and panel and drop-in), and each is scored against the reference points for its own class, so a rating says how well each does among its own build peers. How we rank explains each factor.
| Factor weight | PowerMax PM3-55LK | Progressive Dynamics PD4060CSV |
|---|---|---|
| Overall rating | 3.6/5 | 3.2/5 |
| Value 35% | 70 $2.49 per amp ($137, 55 A) | 38 $4.21 per amp ($252.73, 60 A) |
| Output 10% | 50 55 A | 60 60 A |
| Features 30% | 80 lithium mode, multi-stage charging, fan runs only as needed | 80 lithium mode, multi-stage charging, fan runs only as needed |
| Warranty 25% | 25 2-year warranty | 25 2-year warranty |
Specifications
| PowerMax PM3-55LK | Progressive Dynamics PD4060CSV | |
|---|---|---|
| Charging | ||
| Output | 55 A | 60 A |
| Lithium mode | Yes | Yes |
| Multi-stage charging | Yes | Yes |
| Build | ||
| Build | Standalone | Panel or drop-in |
| Fan runs only as needed | Yes | Yes |
| Remote or display | No | No |
| Weight | 7 lb | 4 lb |
| Warranty | 2 years | 2 years |