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 and the Sterling Power BB1225 25A are evenly matched, rated 3.1 and 3.0. The Renogy 20A DC-DC Charger leads on value. The Sterling Power BB1225 25A wins on charge current and efficiency. The Renogy 20A DC-DC Charger costs $109.01 less ($140.99 vs $250).
Sterling Power BB1225 25A
#6 in Up to 30 AFull review
For boats and vans where keeping the start battery charged matters as much as the house bank.
Amazon $250$250
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 $10.42 per amp ($250, 24 A)).
- Choose the Sterling Power BB1225 25A for charge current (24 A vs 20 A) and efficiency (98% peak efficiency vs 94% peak efficiency).
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 | Sterling Power BB1225 25A |
|---|---|---|
| Overall rating | 3.1/5 | 3.0/5 |
| Value 30% | 59 $7.05 per amp ($140.99, 20 A) | 31 $10.42 per amp ($250, 24 A) |
| Charge current 20% | 50 20 A | 70 24 A |
| Efficiency 10% | 67 94% peak efficiency | 100 98% peak efficiency |
| Features 20% | 25 smart alternator support | 25 smart alternator support |
| Warranty 20% | 25 2-year warranty | 25 2-year warranty |
Specifications
| Renogy 20A DC-DC Charger | Sterling Power BB1225 25A | |
|---|---|---|
| Charging | ||
| Charge current | 20 A | 24 A |
| Input battery | 12 V | 12 V |
| Output battery | 12 V | 12 V |
| Battery types | AGM, gel, flooded, LiFePO4 | - |
| LiFePO4 profile | Yes | Yes |
| Smart alternator support | Yes | Yes |
| Peak efficiency | 94% | 98% |
| Solar | ||
| Solar input | No | No |
| Build | ||
| Bluetooth | No | No |
| Ingress rating | IP32 | - |
| Weight | 2.7 lb | 1.3 lb |
| Warranty | 2 years | 2 years |