Renogy 20A DC-DC Charger
#5 in Up to 30 AFull review
For a van or camper with one 100 Ah lithium battery and a short cable run. It does the basic job well at the lowest price of the big brands.
Amazon $140.99$140.99
The Renogy 20A DC-DC Charger is the better DC-DC charger overall, rated 3.1 to 2.7. The Renogy 20A DC-DC Charger leads on value. The Redarc BCDC Classic 25 wins on charge current and features. The Renogy 20A DC-DC Charger costs $336.01 less ($140.99 vs $477).
Redarc BCDC Classic 25
#8 in Up to 30 AFull review
For overlanders who want a proven engine bay charger. It costs far more than the budget brands.
Amazon $477$477
Prices were last checked October 31, 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 Renogy 20A DC-DC Charger for value ($7.05 per amp ($140.99, 20 A) vs $19.08 per amp ($477, 25 A)).
- Choose the Redarc BCDC Classic 25 for charge current (25 A vs 20 A) and features (solar input, smart alternator support vs smart alternator support).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every up to 30 A DC-DC charger; a clear win is highlighted. How we rank explains each one.
| Factor weight | Renogy 20A DC-DC Charger | Redarc BCDC Classic 25 |
|---|---|---|
| Overall rating | 3.1/5 | 2.7/5 |
| Value 30% | 59 $7.05 per amp ($140.99, 20 A) | 0 $19.08 per amp ($477, 25 A) |
| Charge current 20% | 50 20 A | 75 25 A |
| Efficiency 10% | 67 94% peak efficiency | 50 efficiency not published (neutral score used) |
| Features 20% | 25 smart alternator support | 50 solar input, smart alternator support |
| Warranty 20% | 25 2-year warranty | 25 2-year warranty |
Specifications
| Renogy 20A DC-DC Charger | Redarc BCDC Classic 25 | |
|---|---|---|
| Charging | ||
| Charge current | 20 A | 25 A |
| Input battery | 12 V | 12/24 V |
| Output battery | 12 V | 12 V |
| Battery types | AGM, gel, flooded, LiFePO4 | standard lead acid, calcium, gel, AGM, LiFePO4 |
| LiFePO4 profile | Yes | Yes |
| Smart alternator support | Yes | Yes |
| Peak efficiency | 94% | - |
| Solar | ||
| Solar input | No | MPPT |
| Max solar voltage | - | 32 V |
| Build | ||
| Bluetooth | No | No |
| Ingress rating | IP32 | - |
| Weight | 2.7 lb | 2.2 lb |
| Warranty | 2 years | 2 years |