Last updated: 21 September 2026
Battery and charging
- Charging voltage range
- 13.2–14.7 V for lead acid, 12.6–14.6 V for lithium
- Battery profiles it carries
- Five profiles, including a user-defined one
- Rated output power
- 584 W at 40 A, against 616 W on the MPPT model
- Temperature compensation
- None on lithium; -3mV/°C/2V on everything else
“Charging Voltage Range Lead Acid: 13.2V ~ 14.7V Lithium: 12.6V ~ 14.6V”
Source: cdn.shopify.com/s/files/1/0631/0137/0483/files/DCC1212-204060-Manual.pdf?v=1752029820
“AGM, Gel, Flooded, Lithium-iron Phosphate，User”
Source: renogy.com/collections/dc-dc-battery-chargers/products/12v-40a-dc-to-dc-battery-charger
“584W”
Source: renogy.com/collections/dc-dc-battery-chargers/products/12v-40a-dc-to-dc-battery-charger
“-3mV / ℃ / 2V (Non-Lithium)”
Source: renogy.com/collections/dc-dc-battery-chargers/products/12v-40a-dc-to-dc-battery-charger
Battery care and safety
- Operating temperature range
−25 °C to 60 °C
12v Battery Charger 20A/40A DC to DC Charger | Renogy US · retrieved 14 September 2026
“Operating Temperature Range -4℉ -122℉ /-25 ℃ - 60℃”
Source: renogy.com/collections/dc-dc-battery-chargers/products/12v-40a-dc-to-dc-battery-charger
RBC40D1U-G2_20RBC20D1U-G1_E3_80_9012V_2020A40A_20Battery_20Charger_20EN_E3_80_91_UM_A3.pdf · retrieved 21 September 2026
“Operating Temperature 32°F to 140°F (-25°C to 60°C) Derating < 45°C: Full load; > 45°C: Non-full load; ≥ 60°C: Stop working Storage Temperature -40°F to 185°F (-40°C to 85°C)”
Source: renogy.com/cdn/shop/files/RBC40D1U-G2_20RBC20D1U-G1_E3_80_9012V_2020A40A_20Battery_20Charger_20EN_E3_80_91_UM_A3.pdf
The maker’s own documents give the same figure
Size and fit
- Overall dimensions
- 236.5 × 152.5 × 58.4 mm, 1.88 kg
“Dimensions 9.31 in (236.5 mm)x6.00 in (152.5 mm)x2.30 in(58.4 mm)”
Source: renogy.com/collections/dc-dc-battery-chargers/products/12v-40a-dc-to-dc-battery-charger
Compatibility
- Communication protocol
RS485
12v Battery Charger 20A/40A DC to DC Charger | Renogy US · retrieved 14 September 2026
“Grounding Common Negative Communication Protocol RS485 Communication Operating Temperature Range -4℉ -122℉ /-25 ℃ - 60℃”
Source: renogy.com/collections/dc-dc-battery-chargers/products/12v-40a-dc-to-dc-battery-charger
Bluetooth
QG_RENOGY_2012V_2020A40A_20Battery_20Charger_A0.pdf · retrieved 21 September 2026
“Please make sure: 1. Bluetooth on this phone/tablet is turned on. 2. The device is running properly. 3. The device's Bluetooth is turned on.”
Source: renogy.com/cdn/shop/files/QG_RENOGY_2012V_2020A40A_20Battery_20Charger_A0.pdf
RBC40D1U-G2_20RBC20D1U-G1_E3_80_9012V_2020A40A_20Battery_20Charger_20EN_E3_80_91_UM_A3.pdf · retrieved 21 September 2026
“Parameter Name RBC20D1U RBC40D1U Communication Bluetooth”
Source: renogy.com/cdn/shop/files/RBC40D1U-G2_20RBC20D1U-G1_E3_80_9012V_2020A40A_20Battery_20Charger_20EN_E3_80_91_UM_A3.pdf
The maker’s own documents give different figures
Identity
- Model code
- RBC40D1U
“Model RBC40D1U Terminal Range 10AWG - 8AWG/8AWG - 6AWG Grounding Common Negative”
Source: renogy.com/collections/dc-dc-battery-chargers/products/12v-40a-dc-to-dc-battery-charger
Other findings
- Enclosure rating
No rating is given — the row prints a humidity range
12v Battery Charger 20A/40A DC to DC Charger | Renogy US · retrieved 14 September 2026
“Humidity 0%-95%, No Condensation Maximum Operating Altitude 3000m Enclosure Rating 0%- 95% ,no condensation”
Source: renogy.com/collections/dc-dc-battery-chargers/products/12v-40a-dc-to-dc-battery-charger
IP20, or IP32 — the maker writes both
RBC40D1U-G2_20RBC20D1U-G1_E3_80_9012V_2020A40A_20Battery_20Charger_20EN_E3_80_91_UM_A3.pdf · retrieved 21 September 2026
“Operating Humidity 0% to 95% RH, no condensation IP Rating > IP20 (IP32) Installation Method Surface mounting”
Source: renogy.com/cdn/shop/files/RBC40D1U-G2_20RBC20D1U-G1_E3_80_9012V_2020A40A_20Battery_20Charger_20EN_E3_80_91_UM_A3.pdf
- Idle power consumption
- Under 15 mA when idle
- Input fuse rating
- 60 A in, 50 A out
- Max output current
- 40 A, capped at 584 W
- Model numbers in series
- DCC1212-20 and DCC1212-40
- Protection features
- Four protections on the auxiliary side, two on the starter side
The maker’s own documents give different figures
“Idle Power Consumption ＜15mA”
Source: renogy.com/collections/dc-dc-battery-chargers/products/12v-40a-dc-to-dc-battery-charger
“Input Fuse Rating 60A Output Fuse Rating 50A Charging Efficiency 94%”
Source: renogy.com/collections/dc-dc-battery-chargers/products/12v-40a-dc-to-dc-battery-charger
“Maximum Output Current Rating 40A”
Source: renogy.com/collections/dc-dc-battery-chargers/products/12v-40a-dc-to-dc-battery-charger
“Model DCC1212-20 DCC1212-40 DCC1212-60”
Source: cdn.shopify.com/s/files/1/0631/0137/0483/files/DCC1212-204060-Manual.pdf?v=1752029820
“Protection Mechanisms Auxiliary battery: Overvoltage, overdischarge shutdown, overtemperature, and short-circuit protection; Starter battery: Reverse contact and short-circuit protection”
Source: renogy.com/cdn/shop/files/RBC40D1U-G2_20RBC20D1U-G1_E3_80_9012V_2020A40A_20Battery_20Charger_20EN_E3_80_91_UM_A3.pdf
Certification claims
- Certification claimed by the manufacturer
CE, RoHS and FCC are claimed
12v Battery Charger 20A/40A DC to DC Charger | Renogy US · retrieved 14 September 2026
“Weight 4.14 lb (1.88 kg) Certification CE/RoHS/FCC”
Source: renogy.com/collections/dc-dc-battery-chargers/products/12v-40a-dc-to-dc-battery-charger
RoHS, FCC, CE, RCM and UKCA
RBC40D1U-G2_20RBC20D1U-G1_E3_80_9012V_2020A40A_20Battery_20Charger_20EN_E3_80_91_UM_A3.pdf · retrieved 21 September 2026
“Certification RoHS, FCC, CE, RCM, and UKCA Warranty 2 years”
Source: renogy.com/cdn/shop/files/RBC40D1U-G2_20RBC20D1U-G1_E3_80_9012V_2020A40A_20Battery_20Charger_20EN_E3_80_91_UM_A3.pdf
The maker’s own documents give different figures
Sources
- 12v Battery Charger 20A/40A DC to DC Charger | Renogy USArchived document
Source: renogy.com/collections/dc-dc-battery-chargers/products/12v-40a-dc-to-dc-battery-charger
Retrieved September 14, 2026
- Archived document
Source: renogy.com/cdn/shop/files/RBC40D1U-G2_20RBC20D1U-G1_E3_80_9012V_2020A40A_20Battery_20Charger_20EN_E3_80_91_UM_A3.pdf
Retrieved September 21, 2026
- Archived document
Source: cdn.shopify.com/s/files/1/0631/0137/0483/files/DCC1212-204060-Manual.pdf?v=1752029820
Retrieved September 21, 2026
- Archived document
Source: renogy.com/cdn/shop/files/QG_RENOGY_2012V_2020A40A_20Battery_20Charger_A0.pdf
Retrieved September 21, 2026