Renogy 12V 40A DC-DC Charger
#4 in DC-DCFull review
A cheap, quiet way to add alternator charging to a van or camper with a lithium house battery. Pay more for Victron if you want built-in Bluetooth.
Amazon $177.64$177.64
The Renogy 12V 40A DC-DC Charger is the better charge controller overall, rated 3.8 to 3.3. The Renogy 12V 40A DC-DC Charger leads on features and efficiency. The Redodo 12V 40A DC-DC with MPPT costs $11.65 less ($165.99 vs $177.64).
Redodo 12V 40A DC-DC with MPPT
#9 in DC-DCFull review
For budget van and trailer builds that want alternator and solar charging in one cheap box. Specs are thin, so pick it on price rather than features.
Amazon $165.99$165.99
Prices were last checked October 22, 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 12V 40A DC-DC Charger for features (Bluetooth add-on, lithium profile, temperature sensor, smart-alternator support vs lithium profile; no Bluetooth) and efficiency (94% peak efficiency (maker rating) vs 93% peak efficiency (maker rating)).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every DC-DC charge controller; a clear win is highlighted. How we rank explains each one.
| Factor weight | Renogy 12V 40A DC-DC Charger | Redodo 12V 40A DC-DC with MPPT |
|---|---|---|
| Overall rating | 3.8/5 | 3.3/5 |
| Value 35% | 87 $4.44 per amp of charge current | 90 $4.15 per amp of charge current |
| Features 25% | 82 Bluetooth add-on, lithium profile, temperature sensor, smart-alternator support | 35 lithium profile; no Bluetooth |
| Efficiency 20% | 50 94% peak efficiency (maker rating) | 38 93% peak efficiency (maker rating) |
| Warranty 20% | 25 2-year warranty | 25 2-year warranty |
Specifications
| Renogy 12V 40A DC-DC Charger | Redodo 12V 40A DC-DC with MPPT | |
|---|---|---|
| Charging | ||
| Type | DC-DC charger | DC-DC charger with MPPT solar input |
| Charge current | 40 A | 40 A |
| Battery voltage | 12 V | 12 V |
| Lithium profile | Yes | Yes |
| Custom profile | Yes | - |
| Temperature sensor | Included | No |
| Peak efficiency | 94% | 93% |
| Standby draw | 15 mA | - |
| Inputs | ||
| DC input range | 12 to 16 V | - |
| Isolated | No | - |
| Smart alternator | Yes | - |
| Ignition sensing | Yes | - |
| Monitoring and build | ||
| Bluetooth | Optional add-on | No |
| Display | No | - |
| Load output | No | No |
| Cooling | passive (fan-free) | - |
| Dimensions | 9.31 x 6.00 x 2.30 in | 5.83 x 1.89 x 7.44 in |
| Weight | 4.1 lb | 2.4 lb |
| Warranty | 2 years | 2 years |