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 $175The PowerMax PM3-100LK is the better RV converter charger overall, rated 4.0 to 3.3. The PowerMax PM3-100LK leads on value and output. The PowerMax PM3-100LK costs $169.99 less ($175 vs $344.99).
An easy drop in for an RV that already has a WFCO 9800 deck mount, with lithium detection built in. Pick it for a big battery bank if you can give it a 20 A outlet.
Amazon $344.99Prices 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 PM3-100LK for value ($1.75 per amp ($175, 100 A) vs $4.60 per amp ($344.99, 75 A)) and output (100 A vs 75 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 PM3-100LK | WFCO WF-9875-AD |
|---|---|---|
| Overall rating | 4.0/5 | 3.3/5 |
| Value 35% | 91 $1.75 per amp ($175, 100 A) | 33 $4.60 per amp ($344.99, 75 A) |
| Output 10% | 100 100 A | 90 75 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 PM3-100LK | WFCO WF-9875-AD | |
|---|---|---|
| Charging | ||
| Output | 100 A | 75 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 | 9 lb | 6.8 lb |
| Warranty | 2 years | 2 years |
