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
2.5/5
For owners of small lead-acid or lithium banks who want a sealed, set-and-forget charger that also keeps the starter battery topped up. Bigger lithium banks need a higher-current unit.
- 20 ACharge current
- MPPTSolar input
- 2 yearsWarranty
Check price at Amazon$399
Price checked October 31, 2026. As an Amazon Associate we earn from qualifying purchases.
Pros
- Charges from the alternator and solar together, with an MPPT solar input
- Tops up the starter battery automatically once the house battery is full
- Works with smart alternators and is sealed to IP65
- Simple to set up: one button picks lead-acid, AGM or lithium
Cons
- Only 20 A, so a 100 Ah battery takes about 5 hours of driving from flat
- About $20 per amp, several times the cost of budget chargers
- No app, no custom voltages and a two-year warranty
How it scores
The rating comes from 5 measured or published factors, each scored 0-100 against fixed reference points for its current. How we rank explains each one.
Specifications
| Model number | 40-315 |
|---|---|
| Charging | |
| Charge current | 20 A |
| Input battery | 12/24 V |
| Output battery | 12 V |
| LiFePO4 profile | Yes |
| Smart alternator support | Yes |
| Solar | |
| Solar input | MPPT |
| Build | |
| Bluetooth | No |
| Ingress rating | IP65 |
| Weight | 1.5 lb |
| Warranty | 2 years |
| Released | 2021-03 |
Alternatives in this current
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
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
Compare
Also compared with: Victron SmartSolar MPPT 100/20-48V (charge controller), Victron SmartSolar MPPT 100/30 (charge controller), Victron SmartSolar MPPT 75/15 (charge controller).
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