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 2.5. The Renogy 20A DC-DC Charger leads on value. The CTEK D250SE wins on features. The Renogy 20A DC-DC Charger costs $258.01 less ($140.99 vs $399).
CTEK D250SE
#9 in Up to 30 AFull review
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.
Amazon $399$399
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 $19.95 per amp ($399, 20 A)).
- Choose the CTEK D250SE for 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 | CTEK D250SE |
|---|---|---|
| Overall rating | 3.1/5 | 2.5/5 |
| Value 30% | 59 $7.05 per amp ($140.99, 20 A) | 0 $19.95 per amp ($399, 20 A) |
| Charge current 20% | 50 20 A | 50 20 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 | CTEK D250SE | |
|---|---|---|
| Charging | ||
| Charge current | 20 A | 20 A |
| Input battery | 12 V | 12/24 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% | - |
| Solar | ||
| Solar input | No | MPPT |
| Build | ||
| Bluetooth | No | No |
| Ingress rating | IP32 | IP65 |
| Weight | 2.7 lb | 1.5 lb |
| Warranty | 2 years | 2 years |
| Released | - | 2021-03 |