Our Top 20 Recommendations:
20 Best Onboard Chargers Reviews:
SaleBestseller No. 1 
NOCO GENIUS2D, 2A Direct-Mount Smart Onboard Car Battery Charger, 12V Automotive Charger, Battery Maintainer, Trickle Charger and Desulfator for AGM, Marine, ATV, Truck and Deep Cycle Batteries
- Meet the GENIUS2D - A direct-mount onboard battery charger for an under-the-hood battery charging. It's the all-in-one universal charging solution - battery charger, battery maintainer, trickle charger, float charger, plus battery desulfator.
- Do more with Genius - Designed for 12-volt sealed lead-acid automotive, marine, RV, and deep-cycle batteries, including flooded, gel, AGM, SLA, VRLA and maintenance-free batteries.
- Direct Mount - Securely mounts nearby the battery with its rugged snap-fit mounting bracket and effortlessly installs into most materials with truss-head self-tapping screws.
- Enjoy precision charging - An integrated digital thermal sensor detects the ambient temperature and alters the charge to eliminate over-charging in hot climates and under-charging in cold climates.
- Charge dead batteries - Charge batteries as low as 1-volt, including flooded, gel, and AGM, as well as automotive, marine, and deep-cycle batteries.
SaleBestseller No. 2 
NOCO Genius GEN5X2, 2-Bank, 10A (5A/Bank) Smart Marine Battery Charger, 12V Waterproof Onboard Boat Charger, Battery Maintainer and Desulfator for AGM, Lithium (LiFePO4) and Deep-Cycle Batteries
- Meet the GEN5X2 - Similar to our GENM2, only better. It's 37% smaller and delivers 43% more power. It's one of the best performing onboard marine battery chargers we have ever made.
- Multiple banks - A two-bank onboard battery charger rated a 10-amps - 5-amps per bank - for 12-volt batteries, including marine, boat, starter, and deep-cycle batteries.
- Charging modes - Independently charge and control each battery bank with selectable charging modes - including 12V, 12V AGM, 12V Lithium, and 12V Repair Mode - for all types of lead-acid and lithium-ion batteries.
- Enjoy precision charging - An integrated thermal sensor detects the ambient temperature and alters the charge to eliminate over-charging in hot climates and under-charging in cold climates.
- Charge dead batteries - Charges batteries as low as 1-volt. Or use the all-new force mode that allows you to take control and manually begin charging dead batteries down to zero volts.
SaleBestseller No. 3 
NOCO Genius GEN5X1, 1-Bank, 5A (5A/Bank) Smart Marine Battery Charger, 12V Waterproof Onboard Boat Charger, Battery Maintainer and Desulfator for AGM, Lithium (LiFePO4) and Deep-Cycle Batteries
- Meet the GEN5X1 - Similar to our GENM1, only better. It's 37% smaller and delivers 43% more power. It's one of the best performing onboard marine battery chargers we have ever made.
- Multiple banks - A one-bank onboard battery charger rated a 5-amps - 5-amps per bank - for 12-volt batteries, including marine, boat, starter, and deep-cycle batteries.
- Charging modes - Independently charge and control each battery bank with selectable charging modes - including 12V, 12V AGM, 12V Lithium, and 12V Repair Mode - for all types of lead-acid and lithium-ion batteries.
- Enjoy precision charging - An integrated thermal sensor detects the ambient temperature and alters the charge to eliminate over-charging in hot climates and under-charging in cold climates.
- Charge dead batteries - Charges batteries as low as 1-volt. Or use the all-new force mode that allows you to take control and manually begin charging dead batteries down to zero volts.
SaleBestseller No. 4 
NOCO Genius GEN5X3, 3-Bank, 15A (5A/Bank) Smart Marine Battery Charger, 12V Waterproof Onboard Boat Charger, Battery Maintainer and Desulfator for AGM, Lithium (LiFePO4) and Deep-Cycle Batteries
- Meet the GEN5X3 - Similar to our GENM3, only better. It's 37% smaller and delivers 43% more power. It's one of the best performing onboard marine battery chargers we have ever made.
- Multiple banks - A three-bank onboard battery charger rated a 15-amps - 5-amps per bank - for 12-volt batteries, including marine, boat, starter, and deep-cycle batteries.
- Charging modes - Independently charge and control each battery bank with selectable charging modes - including 12V, 12V AGM, 12V Lithium, and 12V Repair Mode - for all types of lead-acid and lithium-ion batteries.
- Enjoy precision charging - An integrated thermal sensor detects the ambient temperature and alters the charge to eliminate over-charging in hot climates and under-charging in cold climates.
- Charge dead batteries - Charges batteries as low as 1-volt. Or use the all-new force mode that allows you to take control and manually begin charging dead batteries down to zero volts.
SaleBestseller No. 5 
NOCO Genius GENPRO10X1, 1-Bank, 10A (10A/Bank) Smart Marine Battery Charger, 12V Waterproof Onboard Boat Charger, Battery Maintainer and Desulfator for AGM, Lithium (LiFePO4) and Deep-Cycle Batteries
- Meet the GENPRO10X1 - Similar to our GEN1, only better. It's 41% smaller and delivers 33% more power. It's one of the best performing onboard marine battery chargers we have ever made.
- Multiple banks - A one-bank onboard battery charger rated a 10-amps - 10-amps per bank - for 12-volt batteries, including marine, boat, starter, and deep-cycle batteries.
- Charging modes - Independently charge and control each battery bank with selectable charging modes - including 12V, 12V AGM, 12V Lithium, and 12V Repair Mode - for all types of lead-acid and lithium-ion batteries.
- Enjoy precision charging - An integrated thermal sensor detects the ambient temperature and alters the charge to eliminate over-charging in hot climates and under-charging in cold climates.
- Charge dead batteries - Charges batteries as low as 1-volt. Or use the all-new force mode that allows you to take control and manually begin charging dead batteries down to zero volts.
SaleBestseller No. 6 
NOCO Genius GENPRO10X3, 3-Bank, 30A (10A/Bank) Smart Marine Battery Charger, 12V Waterproof Onboard Boat Charger, Battery Maintainer and Desulfator for AGM, Lithium (LiFePO4) and Deep-Cycle Batteries
- Meet the GENPRO10X3 - Similar to our GEN3, only better. It's 27% smaller and delivers 33% more power. It's one of the best performing onboard marine battery chargers we have ever made.
- Multiple banks - A three-bank onboard battery charger rated a 30-amps - 10-amps per bank - for 12-volt batteries, including marine, boat, starter, and deep-cycle batteries.
- Charging modes - Independently charge and control each battery bank with selectable charging modes - including 12V, 12V AGM, 12V Lithium, and 12V Repair Mode - for all types of lead-acid and lithium-ion batteries.
- Enjoy precision charging - An integrated thermal sensor detects the ambient temperature and alters the charge to eliminate over-charging in hot climates and under-charging in cold climates.
- Charge dead batteries - Charges batteries as low as 1-volt. Or use the all-new force mode that allows you to take control and manually begin charging dead batteries down to zero volts.
Bestseller No. 7 
dkplnt 20A 12V to 24V DC to DC Boost Converter On-Board Battery Charger for Flooded, Gel, AGM, and Lithium, Using Multi-Stage Charging in RVs, Commercial Vehicles, Boats, Yachts with Acc Control
- Input Voltage: 11-16v DC（can be connected to 12V battery/auto generator）
- output Voltage：28v DC （During the charging process, the charging voltage of the battery will gradually increase until it reaches 28V）
- Multi-Chemistry Battery Types: AGM, Flooded, Gel, and Lithium
- Over current protection, Over voltage protection, Over temperature shutdown
- High efficiency up to 97%. Aluminium shell with epoxy potting and waterproof IP68
SaleBestseller No. 8 
Renogy 12V 40A DC to DC On-Board Battery Charger for Flooded, Gel, AGM, and Lithium, Using Multi-Stage Charging in RVs, Commercial Vehicles, Boats, Yachts, 40A
- 【Compatible Multiple Battery Types】 Compatible with a multitude of alternator types, the DC-DC battery charger offers correct charging for AGM, Flooded, Gel, and Lithium batteries.
- 【Smart 3-stage Charging】 The DC-DC battery charger will charge your house batteries from the starter battery by 3-stage charging (Bulk, Boost, and Float), to make sure it optimally and automatically charge to 100%.
- 【Various Protections For Ultra Safety】 Offers Over-voltage Protection, Over-temperature Protection, and Reverse Polarity Protection to ensure the operation safety. It also isolates the input and output to prevent voltage transmission errors and interfere with house battery charging.
- 【Protect Your Starter Battery】The DC-DC battery charger is capable of identifying whether the generator is started, to prevent over-discharge of the starting battery and protect the generator.
- 【Reliable Quality】The compact and robust design makes it suitable for all conditions. CE certification.
Bestseller No. 9 
NOCO Genius GENPRO10X4, 4-Bank, 40-Amp (10-Amp Per Bank) Automatic Waterproof Smart Marine Charger, 12V Onboard Battery Charger, Battery Maintainer and Battery Desulfator with Temperature Compensation
- Meet the GENPRO10X4 - Similar to our GEN4, only better. It's 10% smaller and delivers 33% more power. It's one of the best performing onboard marine battery chargers we have ever made.
- Multiple banks - A four-bank onboard battery charger rated a 40-amps - 10-amps per bank - for 12-volt batteries, including marine, boat, starter, and deep-cycle batteries.
- Charging modes - Independently charge and control each battery bank with selectable charging modes - including 12V, 12V AGM, 12V Lithium, and 12V Repair Mode - for all types of lead-acid and lithium-ion batteries.
- Enjoy precision charging - An integrated thermal sensor detects the ambient temperature and alters the charge to eliminate over-charging in hot climates and under-charging in cold climates.
- Charge dead batteries - Charges batteries as low as 1-volt. Or use the all-new force mode that allows you to take control and manually begin charging dead batteries down to zero volts.
SaleBestseller No. 10 
Guest 2711A Guest On-Board Battery Charger 10A / 12V, 2 Bank, 120V Input
- 12V 10 amp 2 bank bank on-board battery charger
- Built-in safety: reverse polarity, over-current, over-voltage, over-temperature and ignition protection. In-line fuses for maximum DC wire protection
- 100% Waterproof (IP67) and shock resistant for all fresh and saltwater applications
- Dedicated battery charging, sensing and control per bank
- For all 12 volt flooded and AGM lead acid batteries. 2 year warranty
Bestseller No. 11 
SOLAR 1002 1.5 Amp 12V Automatic Onboard Battery Charger
- Permanently mount your battery charger to your battery
- Simply plug in power to an extension cable for fast, automatic charging and maintaining
- Automatic operation. No need to press any buttons.
- Battery attachment kit included
SaleBestseller No. 13 
Renogy 12V 30A DC On-Board Input MPPT Battery Charger for Gel, AGM, and Lithium Batteries, Using Multi-Stage Charging, in RVs, Cars, Boats, Yachts, Recommended to Match with 40A ANL Fuse
- 【Recommended to Match with 40A ANL Fuse】The Renogy ANL fuse will protect your controller, wire, and battery from overcurrent.
- 【3-phase MPPT Charging Technology】 With Built-in Maximum Power Point Tracking (MPPT), Renogy DC-DC On-Board Battery Charger will charge your service batteries with maximized solar power, providing 3-phase charging (Bulk, Boost and Float) to regulate the whole charging and ensure the batteries will be accurately charged at the correct voltage levels to 100%.
- 【Multiple Protections】Renogy DC-DC On-Board Battery Charger has multiple intelligent protections includes battery isolation, over-voltage protection, battery temperature protection, over-current protection, overheat protection, reverse current protection, solar panel and alternator reverse polarity protection, guaranteeing charging safety and protecting you batteries.
- 【Light & Small, Ready to be Set Up】 With only 9.6in in length, 5.7in in height, and 3.13lbs in weight, Renogy DC-DC On-Board Battery Charger is ready to be installed and adapt to any tiny narrow installation space, resolving your concern from limited room in you vehicle.
- 【RJ45 Communication Port Featured】 Bluetooth Monitoring Ready! Exclusively available with the BT-2 Bluetooth Module accessory and Renogy DC Home App available on the IOS and Google Play Stores, you can monitor this device remotely and simply through your phone and stay constantly updated.
SaleBestseller No. 14 
Minn Kota 1822105 MK 210D On-Board Battery Charger (2 Banks, 5 amps per bank)
- Part Number: 1822105
- Oem Equivalent Part Number: 702089
- Fit Type: Universal Fit
- 2 banks; 5 amps per bank
- Multi-stage charging and automatic temperature compensation
SaleBestseller No. 15 
NOCO GENIUS GENPRO10X2, 2-Bank, 20A (10A/Bank) Smart Marine Battery Charger, 12V Waterproof Onboard Boat Charger, Battery Maintainer and Desulfator for AGM, Lithium (LiFePO4) and Deep-Cycle Batteries
- Meet the GENPRO10X2 - Similar to our GEN2, only better. It's 19% smaller and delivers 33% more power. It's one of the best performing onboard marine battery chargers we have ever made.
- Multiple banks - A two-bank onboard battery charger rated a 20-amps - 10-amps per bank - for 12-volt batteries, including marine, boat, starter, and deep-cycle batteries.
- Charging modes - Independently charge and control each battery bank with selectable charging modes - including 12V, 12V AGM, 12V Lithium, and 12V Repair Mode - for all types of lead-acid and lithium-ion batteries.
- Enjoy precision charging - An integrated thermal sensor detects the ambient temperature and alters the charge to eliminate over-charging in hot climates and under-charging in cold climates.
- Charge dead batteries - Charges batteries as low as 1-volt. Or use the all-new force mode that allows you to take control and manually begin charging dead batteries down to zero volts.
Bestseller No. 16 
AUTOGEN 2-Bank Marine Battery Charger, 10-Amp (5-Amp Per Bank) Dual Battery Trickle Charger Maintainer, 6V & 12V Onboard Battery Charger and Battery Maintainer
- 【2-Bank, 10-Amp】10 Amp (5 Amp per bank) on-board battery charger for charging and maintaining two 6V/12V batteries independently.
- 【Widely Batteries】Safely charge and maintain all types of Lead-acid batteries, including wet, gel, AGM, and deep-cycle batteries. Marine battery charger is also a great choice for Cars, Trucks, RV, Boats, Yachts.
- 【Automatic Voltage Detection】Auto select 6V/12V mode without keying button, it automatically determines the correct voltage for your target battery. Two bank charger output 2 x 5A depending on the condition of each battery. Constantly regulated voltage patterns allow the battery to be recharged fully and safely without fear of overcharging.
- 【Monitor Power Levels】Solid state two-color LED light indicates the state of the charge. Continuous charging, unlimited time, automatically enter the power maintenance mode after full, extend the battery life, worry-free battery charger for daily use.
- 【Multiple Security Protection】Multiple security protection, such as over current protection, overcharge protection, overheat protection, reverse connection protection, short circuit protection. Rugged and 100% waterproof, waterproof coefficient reach IP65.
Bestseller No. 17 
FORM 15 AMP Onboard Battery Charger for 48 Volt Golf Carts
- 15 Amp Rapid Charger – Charges 48 volt golf carts when mounted directly to the cart. Attach and forget 7-stage smart charging technology.
- Lead Acid Batteries Only – This charger will only work lead acid batteries
- Water & Dust Resistant – With an IP67 weather resistance rating, you don’t have to worry about your charger being damage by water, dust or vibration.
- Excellent Customer Support – We want to make sure that you are 100% satisfied with your FORM golf cart charger. Other golf cart chargers provide EXTREMELY limited support on Amazon – but not us! Our USA based customer service is here to help.
- Family Run Business – We pride ourselves on being ultra-responsive to our customers’ questions, challenges and requests.
SaleBestseller No. 18 
Minn Kota On-Board Alternator Charger
- Charge-on-the-fly: After the boat's alternator has fully charged the starting battery, this technology will reroute the alternator power to the trolling motor batteries
- Battery Protection: extends battery life by protecting your battery from frequent deep discharges
- LED Indicator Lights: Inform of charge stage, maintenance mode status, error notifications and full charge
- Waterproof Construction: All on-board chargers are built to be waterproof, shock-resistant and vibration-resistant
- 3-Year Warranty: All battery chargers come with a full 3-year replacement warranty
SaleBestseller No. 20 
Milwaukee 48-59-1812 M12 or M18 18V and 12V Multi Voltage Lithium Ion Battery Charger w/ Onboard Fuel Gauge
- DUAL CHARGING: This charger can tackle both 18 and 12 volt Milwaukee batteries, holding one of each in the unit at the same time.
- SEQUENTIAL CHARGING: Do not worry about managing charge cycles. This will take care of your batteries one at a time, devoting full charging power to each one.
- BATTERY COMMUNICATION: The charger has a chip that communicates with its batteries, keeping track of how much they have charged. It saves you power by reducing the amount of charge produced as the battery reaches full charge.
- FAST ACTING: Compact batteries can be fully charged in as little as 30 minutes, while extended life batteries can be charged in as little as a single hour.
- INDICATOR LIGHTS let you know whether a battery is charging, fully charged, and whether it needs maintenance or not.
Last update on 2023-01-12 / Affiliate links / Images from Amazon Product Advertising API