Redodo 12V 40A DC-DC Battery Charger with MPPT Solar Input
SVT Score, Upper
Redodo’s 40 A, 12 V DC-DC charger with a built-in MPPT solar input, an ACC wire for smart alternators and reverse charging of the starter battery.
$176
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Usability
4.2 out of 10Redodo states no output wattage, so its 40 A is read at 12.8 V as 512 W, the 5 rung, and it scores 5 on capacity.
Better on capacityRenogy DCC50S DC-DC Charger50 A output works out to 640 W at 12.8 V. $307.99Scores 8.0Its spec table gives charging efficiency up to 93 percent, the 4 rung, so it scores 4 on efficiency.
Its manual gives a smart-alternator input of 12 to 24 V through the included ACC wire to a switched ignition source, a smart-alternator mode, but its start and stop voltages are fixed, so it scores 8 on operating range.
It has a built-in MPPT solar input, but no Bluetooth, no stated galvanic isolation, no published IP rating and no parallel operation, so it scores 4 on features.
Better on featuresRenogy DCC50S DC-DC ChargerTakes up to 660 W of solar through MPPT. $307.99Scores 6.0Redodo publishes no UL 458, UL 1741 or CSA listing for the 40A DC-DC charger, and no record turned up under its model or maker in the Intertek, UL, LabTest, TÜV SÜD, TÜV Rheinland or SGS directories in October 2026, so it scores 2 on verification.
Better on verificationRenogy DCC50S DC-DC ChargerIntertek's directory lists the RBC50D1S to UL 1741. $307.99Scores 8.0Redodo's warranty policy gives DC-DC chargers 2 years, with no proration stated, so it scores 3 on warranty and support.
$175.99 at redodopower.com.
Alternator plus Solar, compact case
The Redodo 12V 40A DC-DC (R12V40A-DC-Z) is Redodo's 40 A alternator-to-house-battery charger with a built-in MPPT solar input, for 12 V house batteries in RVs, vans, trucks and boats.
It suits a buyer charging one 12 V house battery from a vehicle alternator and a small 12 V panel, and who will not need more than 40 A, panels above 30 V or app monitoring.
Strengths
- Built-in MPPT solar input beside the alternator input
- ACC wire for smart alternators
- House battery can charge the starter battery in reverse
- Standby draw under 10 mA
- Weighs 2.43 lb
Drawbacks
- Charging efficiency up to 93 percent
- Solar input limited to 10 to 30 V
- Start and stop voltages are fixed
- No Bluetooth or app monitoring
- No galvanic isolation or IP rating stated
Specs
- CapacityNot applicable
- AC OutputNot applicable
- System Voltage12 V
- Panel PowerNot applicable
- Charge Current40-49 A
- Safety ListingNone verifiable
- Cell TypeNot applicable
- Low-Temp ChargingNot applicable
- Warranty2 Years
- MonitoringNone
- Weight2.4 lb
At a glance
- 50 A Anderson connectors
- 5.83 x 1.89 x 7.44 in
- Six mounting screws in box
- Wakes a BMS-locked battery
Redodo is the brand of Shenzhen Maicheng Technology Innovation Co., Ltd. of Shenzhen, China, which holds its US trademarks and FCC grants, and its press releases give 2020 as its founding year.
It sells direct from redodopower.com, which ships US orders from US warehouses, and through its own Amazon and Walmart seller accounts, with separate stores for Canada, Germany, France, Spain and Japan.
The Redodo 12V 40A DC-DC (store SKU R12V40A-DC-Z) is a 40 A, 12 V on-board charger that charges a house battery from a vehicle alternator through the starter battery or, through a built-in MPPT solar input, from panels; it uses the alternator input when both are available and does not charge from both at once. Its spec table lists SLA, AGM, GEL, CA and LI batteries, a 7 to 15.4 V house-battery range, charging efficiency up to 93 percent, a 600 W maximum alternator input and standby self-consumption under 10 mA. Its manual gives a solar input of 10 to 30 V and up to 600 W, an alternator input of 11.3 to 24 V for traditional alternators and 12 to 24 V for smart alternators, and charge limits of 14.4 V for LiFePO4 and lead acid, 14.7 V for GEL/AGM and 15.4 V for calcium. For smart alternators the included ACC wire goes to a switched ignition source; with the wire connected it starts above 12 V and stops below 11.3 V, and without it above 13 V and below 11 V. The house battery can charge the starter battery in reverse, and it can wake a LiFePO4 battery whose BMS has shut off. It has LED status indicators, a battery-type button and 50 A Anderson connectors, works from 14°F to 113°F, measures 5.83 x 1.89 x 7.44 in and weighs 2.43 lb. In the box, per the manual: the charger, three 50 A Anderson connectors and six mounting screws. Redodo also sells it in its Lead-to-Lithium Upgrade Kit with the 12V 320Ah Mini ($1,258.10 with the 2000W inverter, a 40A charger and the 40A MPPT; $1,366.41 with the 3000W inverter charger and the 40A MPPT). On 2026-10-13 its page still showed a pre-order banner for June 10 beside "Only 24 item(s) left in stock" and an October delivery window.
Questions answered from our data
Is Redodo good?We list 13 Redodo products and score 13 of them. Their overall scores run from 4.9 to 6.3, with a median of 5.7, against a median of 5.5 for all 127 products we score.
How much does a DC-DC charger cost?The 12 dc dc chargers we list run from $141 to $410, with a median of $188.
Are DC-DC chargers UL listed?Two of the 12 dc dc chargers we list carry a UL 458-type listing we could look up by model.
Which DC-DC chargers have Bluetooth?Five of the 12 dc dc chargers we list offer Bluetooth monitoring, built in or as the maker's add-on.
