Charged Reviews
Quick reference
Renogy 12V 40A DC to DC Battery Charger
Model: RBC40D1U-US · SKU: RBC40D1U-US
Prepared Nov 12, 2026
Common specifications
| Charger input | DC (alternator or battery)Source [2] |
|---|---|
| Input voltage | Traditional alternator 13.2-16.0 V DC; smart alternator (Euro 6) 12-16.0 V DCSource [1] |
| Solar input voltage | Not documented |
| Solar input limit | Not documented |
| Output voltage | Not documented |
| Battery voltage | 12 VSource [1] |
| Charge current | 40 ASource [1] |
| Battery chemistry | AGM, Gel, Flooded, Lithium-iron Phosphate, UserSource [1] |
| Power | 584 WSource [1] |
| Isolated | Not documented |
| Engine detection | IGN Signal Wire (for Smart DC Alternator)Source [2] |
| Weight | |
| Enclosure volume | 2.11 L** Calculated from recorded external dimensions |
| Warranty term | 2 yearsSource [1] |
All recorded specifications
| Battery chemistry | AGM, Gel, Flooded, Lithium-iron Phosphate, UserDocumented claim ConditionsPrinted as "Battery Types AGM, Gel, Flooded, Lithium-iron Phosphate，User"; "User" is a custom charging mode. Location: ELECTRICAL DATA, Battery Types Printed as "Battery Types AGM, Gel, Flooded, Lithium-iron Phosphate，User"; "User" is a custom charging mode. Location: ELECTRICAL DATA, Battery Types |
|---|---|
| Battery voltage | 12 VDocumented claim ConditionsPrinted as "System Voltage 12V-12V": a 12V starter battery charging a 12V house battery. Location: ELECTRICAL DATA, System Voltage Printed as "System Voltage 12V-12V": a 12V starter battery charging a 12V house battery. Location: ELECTRICAL DATA, System Voltage |
| Charge current | 40 ADocumented claim ConditionsRenogy's maximum output current rating. The page states the charger adjusts output power in high temperatures; no derating curve is published. Location: ELECTRICAL DATA, Maximum Output Current Rating Renogy's maximum output current rating. The page states the charger adjusts output power in high temperatures; no derating curve is published. Location: ELECTRICAL DATA, Maximum Output Current Rating |
| Charger input | DC (alternator or battery)Documented claim ConditionsPrinted as "Step 4. Connect the Battery Charger to a Starter Battery"; the guide covers RBC20D1U and RBC40D1U together and prints no solar input. Location: PDF page 14, Step 4 Printed as "Step 4. Connect the Battery Charger to a Starter Battery"; the guide covers RBC20D1U and RBC40D1U together and prints no solar input. Location: PDF page 14, Step 4 |
| Communications | RS485Documented claim ConditionsPrinted as "Communication Protocol RS485 Communication". The page's description mentions Bluetooth and the DC Home app, while its FAQ says communication needs the separately sold BT-2 Bluetooth module; whether this code has Bluetooth built in is not settled by the page, so only RS485 is recorded. Location: General data, Communication Protocol Printed as "Communication Protocol RS485 Communication". The page's description mentions Bluetooth and the DC Home app, while its FAQ says communication needs the separately sold BT-2 Bluetooth module; whether this code has Bluetooth built in is not settled by the page, so only RS485 is recorded. Location: General data, Communication Protocol |
| Dimensions | 152.5 D × 236.5 W × 58.4 H mm6 D × 9.31 W × 2.3 H in convertedDocumented claim ConditionsPrinted as "9.31 in (236.5 mm)x6.00 in (152.5 mm)x2.30 in(58.4 mm)", read in that order as width, depth and height. Location: General data, Dimensions Printed as "9.31 in (236.5 mm)x6.00 in (152.5 mm)x2.30 in(58.4 mm)", read in that order as width, depth and height. Location: General data, Dimensions |
| Engine detection | IGN Signal Wire (for Smart DC Alternator)Documented claim ConditionsPrinted as "Step 5. Install a IGN Signal Wire (for Smart DC Alternator)"; shared guide for RBC20D1U and RBC40D1U (traditional alternators need no IGN connection, PDF page 14). Location: PDF page 16, Step 5 Printed as "Step 5. Install a IGN Signal Wire (for Smart DC Alternator)"; shared guide for RBC20D1U and RBC40D1U (traditional alternators need no IGN connection, PDF page 14). Location: PDF page 16, Step 5 |
| Input voltage | Traditional alternator 13.2-16.0 V DC; smart alternator (Euro 6) 12-16.0 V DCDocumented claim ConditionsPrinted as "Alternator Input Voltage Traditional Alternator: 13.2-16.0VDC Smart Alternator (Euro 6): 12-16.0VDC". Location: ELECTRICAL DATA, Alternator Input Voltage Printed as "Alternator Input Voltage Traditional Alternator: 13.2-16.0VDC Smart Alternator (Euro 6): 12-16.0VDC". Location: ELECTRICAL DATA, Alternator Input Voltage |
| Max efficiency | 94 %Documented claim ConditionsPrinted as "Charging Efficiency 94%" with no load point or test condition. Location: ELECTRICAL DATA, Charging Efficiency Printed as "Charging Efficiency 94%" with no load point or test condition. Location: ELECTRICAL DATA, Charging Efficiency |
| Operating temperature | -25 to 60 °C-13 to 140 °F convertedDocumented claim ConditionsPrinted as "-4℉ -122℉ /-25 ℃ - 60℃". The Celsius figures are recorded; the Fahrenheit figures printed beside them (-4 to 122 °F, which is -20 to 50 °C) do not agree with them. Location: General data, Operating Temperature Range Printed as "-4℉ -122℉ /-25 ℃ - 60℃". The Celsius figures are recorded; the Fahrenheit figures printed beside them (-4 to 122 °F, which is -20 to 50 °C) do not agree with them. Location: General data, Operating Temperature Range |
| Other compliance claims | CE/RoHS/FCCDocumented claim ConditionsRecorded exactly as Renogy prints it. No certificate, test report or issuer record is linked, and none was checked. Location: General data, Certification Recorded exactly as Renogy prints it. No certificate, test report or issuer record is linked, and none was checked. Location: General data, Certification |
| Power | 584 WDocumented claim ConditionsRenogy's rated output power; no output voltage is stated beside it. Location: ELECTRICAL DATA, Output Power Renogy's rated output power; no output voltage is stated beside it. Location: ELECTRICAL DATA, Output Power |
| Protection features | Reverse Polarity Protection, Overvoltage Protection, Over Discharge Protection, Overcurrent Protection, Over Temperature ProtectionDocumented claim ConditionsRenogy's list, printed separated by slashes. Location: General data, Protection Renogy's list, printed separated by slashes. Location: General data, Protection |
| Storage temperature | -40 to 85 °C-40 to 185 °F convertedDocumented claim ConditionsPrinted as "-4℉ -122℉ /-40 ℃ - 85℃". The Celsius figures are recorded; the Fahrenheit figures printed beside them repeat the operating range and do not agree. Location: General data, Storage Temperature Range Printed as "-4℉ -122℉ /-40 ℃ - 85℃". The Celsius figures are recorded; the Fahrenheit figures printed beside them repeat the operating range and do not agree. Location: General data, Storage Temperature Range |
| Weight | 1.88 kg4.14 lb convertedDocumented claim ConditionsPrinted as "Weight 4.14 lb (1.88 kg)". Location: General data, Weight Printed as "Weight 4.14 lb (1.88 kg)". Location: General data, Weight |
Warranty
| Remedy | Repair, or replacement with a new or refurbished product, at Renogy's option; refund if it cannot repair or replaceDocumented claim ConditionsPrinted as "Renogy will, at its option, either repair the defective product or replace it with a new or refurbished product of equal or greater performance and reliability." in the Renogy Limited Warranty (RNG-4-243, rev. A7), Page 1, Limited Warranty for All, captured on September 26, 2026. Location: Page 1, Limited Warranty for All Printed as "Renogy will, at its option, either repair the defective product or replace it with a new or refurbished product of equal or greater performance and reliability." in the Renogy Limited Warranty (RNG-4-243, rev. A7), Page 1, Limited Warranty for All, captured on September 26, 2026. Location: Page 1, Limited Warranty for All |
|---|---|
| Transfer to another owner | Original purchaser only; if gifted or resold, the claim goes through the original purchaserDocumented claim ConditionsPrinted as "This warranty extends only to the original Purchaser. If gifted or resold the customer must go through the original Purchaser in order to claim warranty." in the Renogy Limited Warranty (RNG-4-243, rev. A7), General Conditions for Warranty Claims, captured on September 26, 2026. Location: General Conditions for Warranty Claims Printed as "This warranty extends only to the original Purchaser. If gifted or resold the customer must go through the original Purchaser in order to claim warranty." in the Renogy Limited Warranty (RNG-4-243, rev. A7), General Conditions for Warranty Claims, captured on September 26, 2026. Location: General Conditions for Warranty Claims |
| Coverage conditions | Excludes normal wear and tear, improper installation, operation and storage, unauthorized repair or modification, misuse, surges and force majeure; the invoice and a written claim within the term are requiredDocumented claim ConditionsPrinted as "The warranty does not cover failures and damages that result from normal wear and tear, improper installation, operation, and storage" in the Renogy Limited Warranty (RNG-4-243, rev. A7), Exclusions and Limitations, captured on September 26, 2026. Location: Exclusions and Limitations Printed as "The warranty does not cover failures and damages that result from normal wear and tear, improper installation, operation, and storage" in the Renogy Limited Warranty (RNG-4-243, rev. A7), Exclusions and Limitations, captured on September 26, 2026. Location: Exclusions and Limitations |
| Coverage starts | From the date of purchase by the userDocumented claim ConditionsPrinted as "The warranty is in effect from the date of purchase by the user" in the Renogy Limited Warranty (RNG-4-243, rev. A7), Page 1, Limited Warranty for All, captured on September 26, 2026. Location: Page 1, Limited Warranty for All Printed as "The warranty is in effect from the date of purchase by the user" in the Renogy Limited Warranty (RNG-4-243, rev. A7), Page 1, Limited Warranty for All, captured on September 26, 2026. Location: Page 1, Limited Warranty for All |
| Warranty term | 2 yearsDocumented claim ConditionsPrinted as "Material and workmanship warranty 2-year". Renogy's page links its general limited warranty document for the terms; that document was not read for this record. Location: WARRANTY INFORMATION Printed as "Material and workmanship warranty 2-year". Renogy's page links its general limited warranty document for the terms; that document was not read for this record. Location: WARRANTY INFORMATION |
| Labor and shipping | Labor not covered; returns for valid warranty service ship at the warrantor's expense and riskDocumented claim ConditionsPrinted as "This warranty does not cover labor." in the Renogy Limited Warranty (RNG-4-243, rev. A7), General Conditions for Warranty Claims and Exclusions and Limitations, captured on September 26, 2026. Location: General Conditions for Warranty Claims and Exclusions and Limitations Printed as "This warranty does not cover labor." in the Renogy Limited Warranty (RNG-4-243, rev. A7), General Conditions for Warranty Claims and Exclusions and Limitations, captured on September 26, 2026. Location: General Conditions for Warranty Claims and Exclusions and Limitations |
Certificate records
No records documented.
Sources and revisions
- 12V 20A/40A DC to DC Battery Charger | Renogy US (September 23, 2026 capture)Official product page · Checked https://www.renogy.com/products/12v-40a-dc-to-dc-battery-charger
- Renogy 12V 20A/40A DC-DC Battery Charger Quick Guide (RBC20D1U-G1/RBC40D1U-G2), version A4, April 15, 2025Official document · Revision A4 · 2025-04-15 · Checked https://cdn.shopify.com/s/files/1/0631/0137/0483/files/QG_RENOGY_2012V_2020A40A_20Battery_20Charger_A0.pdf?v=1752026840
- Renogy Limited Warranty (RNG-4-243 rev. A7)Official warranty · Checked https://cdn.shopify.com/s/files/1/0631/0137/0483/files/RNG-4-243_Limited_warranty_A7_ALL_ac847cf3-801a-4727-8945-626d83ebe543.pdf?v=1777020452
- Renogy storefront product data for the 12V 20A/40A DC to DC Battery Charger (September 23, 2026 capture)Official product page · Checked https://www.renogy.com/products/12v-40a-dc-to-dc-battery-charger.js