Renogy 12V 40A DC to DC Battery Charger
SVT Score, Mid
A 584 W, 40 A DC-DC charger for 12 V house batteries with a smart-alternator mode, four current settings and Bluetooth through an add-on module.
$187
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Usability
3.9 out of 10Renogy rates its output at 584 W, on the 500 to 599 W rung that holds the typical charger, so 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 8.0Renogy's product page states 94 percent charging efficiency, while its manual gives 94 percent when stepping voltage down and over 90 percent when boosting, so it scores 4 on efficiency.
It has a smart-alternator (Euro 6) mode that starts charging at 12 V and stops at 11.5 V with the IGN wire connected, against 13.2 V and 12.7 V in traditional mode, but the manual lists no setting for those thresholds, so it scores 8 on operating range.
Bluetooth comes only through the separately sold BT-2 module, the case is IP32, input and output share a common negative, and Renogy offers no parallel operation or solar input, so it scores 2 on features.
Better on featuresRenogy DCC50S DC-DC ChargerTakes up to 660 W of solar through MPPT. $307.99Scores 6.0No certifier directory searched (Intertek, UL Product iQ, CSA, the CEC list, LabTest, TÜV SÜD, TÜV Rheinland and SGS) lists the RBC40D1U, and Renogy's page claims only FCC and CE marks, so it scores 2 on verification.
Better on verificationRenogy DCC50S DC-DC ChargerIntertek's directory lists the RBC50D1S to UL 1741. $307.99Scores 8.0Renogy's warranty document and product page both give 2 years on materials and workmanship, so it scores 3 on warranty and support.
Renogy sets warranty terms by model, for the original buyer only, and takes unused renogy.com orders back within 30 days, lithium batteries within 7.
$186.99 at renogy.com.
Smart-Alternator mode, 584 W, IP32 case
The RBC40D1U is Renogy's second-generation 12 V 40 A DC-DC charger for charging a van or RV house battery from the starter battery and alternator.
It suits a buyer with a 100 to 200 Ah lithium house battery and a smart alternator who wants charge current adjustable from 10 to 40 A in the app, and who will not need solar input, built-in Bluetooth or a weatherproof mount.
Strengths
- 584 W output at 94 percent charging efficiency
- Smart-alternatorEuro 6) mode that starts at 12 V
- Charge current settable to 4030, 20 or 10 A
- Under 15 mA idle draw
- Full load to 45 °C before derating
Drawbacks
- Bluetooth needs the BT-2 modulesold separately
- IP32 casenot rated for wet or engine-bay mounting
- Start and stop voltages are fixedthe manual lists no setting for them
- Manual gives over 90 percent when boostingagainst 94 percent stepping down
- Weight given as 4.14 lb on the product page and up to 4.4 lb in the manual
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
- MonitoringBluetooth add-on
- Weight4.1 lb
At a glance
- RS485 port for BT-2 module
- 2 m temp sensor in the box
- 3 m IGN signal wire included
- 9.31 x 6.00 x 2.30 in
Renogy is the brand of RNG International, Inc., of Ontario, California, which Dr. Yi Li founded in 2010.
It sells direct from renogy.com and its Amazon and eBay brand stores, and through Home Depot, Lowe's, Best Buy, Camping World and Walmart's marketplace.
The Renogy RBC40D1U (RBC40D1U-G2 in its manual) is a second-generation 12 V to 12 V buck-boost DC-DC charger rated 40 A and 584 W of output, 600 W maximum input, with 94 percent charging efficiency by Renogy's product page. It takes 12 to 16 V from a smart (Euro 6) alternator or 13.2 to 16 V from a traditional one: in traditional mode it starts charging when the starter battery holds 13.2 V for 15 seconds and stops at 12.7 V, and with the IGN signal wire connected for a smart alternator it starts at 12 V and stops at 11.5 V. It charges sealed, AGM, gel, flooded and lithium iron phosphate batteries, plus a user mode set in the DC Home app, can wake a lithium battery that has gone to sleep, and draws under 15 mA at idle; charge current can be set to 40, 30, 20 or 10 A. It runs at full load to 45 °C (113 °F), then loses 5 A for every 2 °C until it stops at 60 °C (140 °F). The case is rated IP32, cooled naturally, measures 9.31 x 6.00 x 2.30 in (236.5 x 152.5 x 58 mm) and weighs 4.14 lb by the product page, with an RS485 port for Renogy's BT-2 Bluetooth module. Renogy recommends a 60 A input fuse and a 50 A output fuse. The box holds the charger, a 2 m battery temperature sensor, a 3 m IGN signal wire, four ST4 x 16 mm mounting screws and the quick guide; Renogy's page also lists four terminal rings. Renogy sells it at $186.99, on the same page as the 20 A RBC20D1U.
Questions answered from our data
Is Renogy good?We list 58 Renogy products and score 58 of them. Their overall scores run from 3.7 to 6.6, with a median of 5.4, against a median of 5.4 for all 58 products we score.
How much does a DC-DC charger cost?The 7 dc dc chargers we list run from $141 to $410, with a median of $206.
Are DC-DC chargers UL listed?Two of the 7 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 7 dc dc chargers we list offer Bluetooth monitoring, built in or as the maker's add-on.
