PowerMax PM4-75
#3 in StandaloneFull review
A low cost standalone converter for owners who are comfortable setting a charge voltage by hand. Its high output suits a large lithium bank.
Amazon $149$149
The PowerMax PM4-75 is the better RV converter charger overall, rated 3.9 to 3.6. The PowerMax PM4-75 leads on value and output. The PowerMax PM4-55 costs $6 less ($143 vs $149).
PowerMax PM4-55
#6 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 $143$143
Prices were last checked November 3, 2026 and are subject to change; the price and availability shown by the retailer at the time of purchase apply.
Which should you buy?
- Choose the PowerMax PM4-75 for value ($1.99 per amp ($149, 75 A) vs $2.60 per amp ($143, 55 A)) and output (75 A vs 55 A).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every standalone RV converter charger; a clear win is highlighted. How we rank explains each one.
| Factor weight | PowerMax PM4-75 | PowerMax PM4-55 |
|---|---|---|
| Overall rating | 3.9/5 | 3.6/5 |
| Value 35% | 83 $1.99 per amp ($149, 75 A) | 67 $2.60 per amp ($143, 55 A) |
| Output 10% | 90 75 A | 50 55 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 PM4-75 | PowerMax PM4-55 | |
|---|---|---|
| Charging | ||
| Output | 75 A | 55 A |
| Lithium mode | Yes | Yes |
| Multi-stage charging | Yes | Yes |
| Build | ||
| Build | Standalone | Standalone |
| Fan runs only as needed | Yes | Yes |
| Remote or display | No | No |
| Weight | 8 lb | 7 lb |
| Warranty | 2 years | 2 years |