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
The Sterling Power BB1225 25A is the better DC-DC charger overall, rated 3.0 to 2.9. The Sterling Power BB1225 25A leads on value. The Redarc BCDC Alpha 25 wins on features. The Sterling Power BB1225 25A costs $439 less ($250 vs $689).
Redarc BCDC Alpha 25
#7 in Up to 30 AFull review
For 4x4 and truck builds that need the toughest sealed charger with Bluetooth. Buyers on a budget get more amps per dollar elsewhere.
Redarc $689$689
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 Sterling Power BB1225 25A for value ($10.42 per amp ($250, 24 A) vs $27.56 per amp ($689, 25 A)).
- Choose the Redarc BCDC Alpha 25 for features (solar input, smart alternator support, Bluetooth 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 | Sterling Power BB1225 25A | Redarc BCDC Alpha 25 |
|---|---|---|
| Overall rating | 3.0/5 | 2.9/5 |
| Value 30% | 31 $10.42 per amp ($250, 24 A) | 0 $27.56 per amp ($689, 25 A) |
| Charge current 20% | 70 24 A | 75 25 A |
| Efficiency 10% | 100 98% peak efficiency | 50 efficiency not published (neutral score used) |
| Features 20% | 25 smart alternator support | 75 solar input, smart alternator support, Bluetooth |
| Warranty 20% | 25 2-year warranty | 25 2-year warranty |
Specifications
| Sterling Power BB1225 25A | Redarc BCDC Alpha 25 | |
|---|---|---|
| Charging | ||
| Charge current | 24 A | 25 A |
| Input battery | 12 V | 12/24 V |
| Output battery | 12 V | 12 V |
| Battery types | - | AGM, gel, calcium, standard lead acid, LiFePO4, heated LiFePO4 |
| LiFePO4 profile | Yes | Yes |
| Smart alternator support | Yes | Yes |
| Peak efficiency | 98% | - |
| Solar | ||
| Solar input | No | MPPT, up to 500 W |
| Max solar voltage | - | 48 V |
| Build | ||
| Bluetooth | No | Yes |
| Ingress rating | - | IP67/IP69K |
| Weight | 1.3 lb | 2 lb |
| Warranty | 2 years | 2 years |