Battery Charger
3,536,248 results

Item Price Seller
12V 5A Automatic Smart Battery Charger, Maintainer & Desulfator for Lead Acid Batteries, Car Battery Charger 100-240V AC input

12V 5A Automatic Smart Battery Charger, Maintainer & Desulfator for Lead Acid Batteries, Car Battery Charger 100-240V AC input

$33.90Aliexpress
AmazonBasics Ni-MH AA & AAA Battery Charger With USB Port

AmazonBasics Ni-MH AA & AAA Battery Charger With USB Port

Category: Electronics
$14.99Amazon
Black & Decker BM3B 6V and 12V Battery Charger / Maintainer

Black & Decker BM3B 6V and 12V Battery Charger / Maintainer

Category: Automotive
$19.99Amazon
NOCO Genius G3500 6V/12V 3.5A UltraSafe Smart Battery Charger

NOCO Genius G3500 6V/12V 3.5A UltraSafe Smart Battery Charger

Category: Automotive
$32.81 - $54.69Amazon
EBL 12 Bay LCD AA AAA 9V Battery Charger for Rechargeable Batteries, New Released

EBL 12 Bay LCD AA AAA 9V Battery Charger for Rechargeable Batteries, New Released

Category: Electronics
$26.99 - $42.49Amazon
NEW NOCO GENIUS G7200 12V / 24V 7200mA CAR ATV RV SMART BATTERY CHARGER

NEW NOCO GENIUS G7200 12V / 24V 7200mA CAR ATV RV SMART BATTERY CHARGER

Category: Battery Chargers
$79.99Ebay
Black & Decker BC15BD 15 Amp Bench Battery Charger with Engine Start Timer

Black & Decker BC15BD 15 Amp Bench Battery Charger with Engine Start Timer

Category: Automotive
$42.49 - $49.99Amazon
Portable Mini Slim 20000mAh Car Jump Starter Engine Battery Charger Power Bank

Portable Mini Slim 20000mAh Car Jump Starter Engine Battery Charger Power Bank

Category: Battery Chargers
$37.99Ebay
Portable Mini Slim 20000mAh Car Jump Starter Engine Battery Charger Power Bank

Portable Mini Slim 20000mAh Car Jump Starter Engine Battery Charger Power Bank

Category: Battery Chargers
$36.85Ebay
Schumacher SC-1200A-CA SpeedCharge 12Amp 6/12V Fully Automatic Battery Charger

Schumacher SC-1200A-CA SpeedCharge 12Amp 6/12V Fully Automatic Battery Charger

Category: Misc.
$40.16 - $57.11Amazon
Car Booster 12V Battery Charger Power Compressor Portable Jump Starter USB Auto

Car Booster 12V Battery Charger Power Compressor Portable Jump Starter USB Auto

Category: Battery Chargers
$114.95Ebay
Car Booster 12v Battery Charger Power Compressor Portable Jump Starter USB Auto

Car Booster 12v Battery Charger Power Compressor Portable Jump Starter USB Auto

Category: Battery Chargers
$64.95Ebay
Nitecore NEW-i2 Universal Battery Charger 2-Slot Smart Charging Li-ion/IMR/Ni-MH

Nitecore NEW-i2 Universal Battery Charger 2-Slot Smart Charging Li-ion/IMR/Ni-MH

Category: Battery Chargers
$14.95Ebay
Extreme Max 1229.4000 Battery Buddy Intelligent 6V / 12V Battery Charger / Maintainer

Extreme Max 1229.4000 Battery Buddy Intelligent 6V / 12V Battery Charger / Maintainer

Category: Automotive
$18.22 - $42.49Amazon
Smart LCD Battery Charger Rechargeable USB Charger for 26650 18650 18500 18350 17670 14500 Lithium Battery 3.7V

Smart LCD Battery Charger Rechargeable USB Charger for 26650 18650 18500 18350 17670 14500 Lithium Battery 3.7V

$17.65Aliexpress
EBL Smart Battery Charger for 18650 AA AAA & C Size Li-ion Ni-MH Ni-CD Rechargeable Battery with iQuick Technology

EBL Smart Battery Charger for 18650 AA AAA & C Size Li-ion Ni-MH Ni-CD Rechargeable Battery with iQuick Technology

Category: Electronics
$10.99 - $40.16Amazon
54.6V2A charger 54.6v 2A electric bike lithium battery charger for 48V lithium battery pack XLRM Plug 54.6V2A charger

54.6V2A charger 54.6v 2A electric bike lithium battery charger for 48V lithium battery pack XLRM Plug 54.6V2A charger

$18.91Aliexpress
Original Nitecore i2 Intelligent Battery Charger with LCD Display Universal For 26650 18650 14500 AA AAA 16340 Charger

Original Nitecore i2 Intelligent Battery Charger with LCD Display Universal For 26650 18650 14500 AA AAA 16340 Charger

$12.79Aliexpress
Original XTAR VC2 Universal LCD Screen Display XTAR VC2 Battery charger for 10440/16340/14500/14650/17670/18350/18500/18650

Original XTAR VC2 Universal LCD Screen Display XTAR VC2 Battery charger for 10440/16340/14500/14650/17670/18350/18500/18650

$14.99Aliexpress
EBL Universal Battery Charger for AA AAA C D 9V Ni-MH Ni-CD Rechargeable Batteries with LCD Display and Discharge Functions

EBL Universal Battery Charger for AA AAA C D 9V Ni-MH Ni-CD Rechargeable Batteries with LCD Display and Discharge Functions

Category: Electronics
$17.99 - $40.16Amazon
Liitokala lii500 LCD 3.7V/1.2V AA/AAA 18650/26650/16340/14500/10440/18500 Battery Charger with screen+12V 2A Adapter USB 5V1A

Liitokala lii500 LCD 3.7V/1.2V AA/AAA 18650/26650/16340/14500/10440/18500 Battery Charger with screen+12V 2A Adapter USB 5V1A

$19.38Aliexpress
Hot-Selling Opus BT-C700 NiCd NiMh Digital Intelligent 4 Slots Battery Charger For EU/US Plug High-quality Charger For Battery

Hot-Selling Opus BT-C700 NiCd NiMh Digital Intelligent 4 Slots Battery Charger For EU/US Plug High-quality Charger For Battery

$20.99Aliexpress
TK Original New Nitecore I4 18650 Battery Charger Universal Digicharger for AA AAA 26650 14500 Li-ion Lithium Batteries Charging

TK Original New Nitecore I4 18650 Battery Charger Universal Digicharger for AA AAA 26650 14500 Li-ion Lithium Batteries Charging

$21.76Aliexpress
Original Nitecore D2 LCD Display Battery Charger with Verification Number for 26650 18650 16340 RCR123 14500 10400 AAAA AAA AA C

Original Nitecore D2 LCD Display Battery Charger with Verification Number for 26650 18650 16340 RCR123 14500 10400 AAAA AAA AA C

$17.45Aliexpress
Automatic 12 Volt Battery Float Trickle Charger Car Maintainer Truck Lawnmower

Automatic 12 Volt Battery Float Trickle Charger Car Maintainer Truck Lawnmower

Category: Battery Chargers
$10.95Ebay
12V 20000mAh Car Jump Starter Emergency Charger Auto Power Bank Battery Minimax#

12V 20000mAh Car Jump Starter Emergency Charger Auto Power Bank Battery Minimax#

Category: Battery Chargers
$31.94Ebay
Deltran Battery Tender Junior 12 Volt Jr 12v 021-0123 - 6 Pack

Deltran Battery Tender Junior 12 Volt Jr 12v 021-0123 - 6 Pack

Category: Battery Chargers
$118.73Ebay
NITECORE New i4 Intellicharger 2016 Li-ion Smart Charger w/ 12V DC Car Charger

NITECORE New i4 Intellicharger 2016 Li-ion Smart Charger w/ 12V DC Car Charger

Category: Battery Chargers
$17.95Ebay
Liitokala lii500 LCD charger for 3.7V 18650 26650 18500 Cylindrical Lithium Batteries,lii-500 1.2V AA AAA NiMH Battery Charger

Liitokala lii500 LCD charger for 3.7V 18650 26650 18500 Cylindrical Lithium Batteries,lii-500 1.2V AA AAA NiMH Battery Charger

$19.35Aliexpress
EBL 8 Bay AA, AAA, Ni-MH, Ni-Cd Rechargeable Battery Charger

EBL 8 Bay AA, AAA, Ni-MH, Ni-Cd Rechargeable Battery Charger

Category: Electronics
$4.95 - $9.00Amazon

Battery Charger Product Descriptions

AmazonBasics Ni-MH AA & AAA Battery Charger With USB Port

4-hour Ni-MH battery charger with USB charge port.

Recharges 2 or 4 AA / AAA Ni-MH batteries at a time.

Protects against wrong polarity charging and over charging.

Built-in switching power technology for worldwide use (100-240 V AC).

Retractable AC plug; slim profile; ideal for travel.


EBL 8 Bay AA, AAA, Ni-MH, Ni-Cd Rechargeable Battery Charger

This EBL 808 charger can charge 2/4/6/8 AA/AAA Ni-MH/Ni-Cd rechargeable batteries..

Controlled by MCU, automatically stop charging when detecting improper input voltage, defective or short circuit or non rechargeable batteries..

Using -∆V intellectual cut-off charging method, automatically turn to trickle charge, prevent the batteries from over-voltage, over-current or over-heat..

AC 100-240V 50/60Hz input, 2.8V DC output shorten the time of charging (most similar chargers are 2.4V)..

Constant current charging would protect the batteries against current fluctuation and keep using the charger safely..

Model:
EBL-808 Latest Version

Features:
LED display the charging statues: shows orange(charging) - shows green(full charged).
Controlled by MCU, automatically stop charging when detecting improper input voltage, defective or short circuit or non rechargeable batteries.
Using -∆V intellectual cut-off charging method, automatically turn to trickle charge, prevent the batteries from over-voltage, over-current or over-heat.

Compatible:
Can both charge AA and AAA Ni-MH Ni-Cd rechargeable batteries(Do not charge alkaline or Lithium batteries)

How many batteries can be charged at a time:
2/4/6/8 AA or AAA batteries together at a time, need to charge batteries in pairs, do not charge uneven amount of batteries
4 LEDs show the status of charging, never charge 1 AA + 1 AAA together at 2 slots which are controlled by 1 LED

Charging Time Table:
2 to 8 pcs AAA 500-1200mAh: 3 - 8 hours(180mA output)
2 to 8 pcs AA 1300-2800mAh: 6 - 15 hours(200mA output)

Attention:
* Please ensure the battery installed is correct: make the +/- pole of the battery is match for the +/- pole of the charger.
* Never mix charge different type and different capacity of batteries under the same LED indicator.
* Using environment: 0℃ to 40℃, it is normal phenomenon that the battery is warmer than room temperature when charging.
* Do not disassemble or reassemble the charger by yourself for safety reason.

Portable and Lightweight:
Dimensions: 6.9 x 3.0 x 1.0 inch
Weight : 6.0 oz.


EBL Universal Battery Charger for AA AAA C D 9V Ni-MH Ni-CD Rechargeable Batteries with LCD Display and Discharge Functions

This EBL-906 charger can charge 1-4 AA/AAA/C/D and 1-2 9V Ni-MH/Ni-Cd rechargeable batteries, independent charging slot, can charge different size batteries freely..

Automatically stop charging when detecting improper input voltage, defective or short circuit or non rechargeable batteries..

Controlled by MCU, and using -∆V intellectual cut-off charging method, automatically turn to trickle charge, prevent the batteries from over-voltage, over-current or over-heat..

Constant current charging mode would protect the batteries against current fluctuation and keep using the charger safely..

AC and DC input design, applied to worldwide voltage - AC 100-240V 50/60Hz, convenient everywhere..

About Products
EBL-906 battery charger, ultra fit for AA, AAA, C, D, 9V Ni-MH/Ni-CD rechargeable batteries.
It has both AC and DC plug, smart LCD shows the charging status of each battery (LED for 9V, AC plug included).
Both recharge and discharge function by switch the blue button below the LCD screen.
Negative delta V (- ∆V) cut-off function (except for 9V batteries), overcharge protection, short circuit protection and non-rechargeable or bad cell detection make it more easier for usage.

Specification of charger
Input: AC 100-240V AC 50/60HZ 10W, DC 12V 800mA
Output: AA/AAA/C/D Ni-MH Ni-CD: 1.2V DC*4 1000mA; 9V Ni-MH Ni-CD: DC*2 30mA
Discharge current: 200-300mA
No load power consumption: 1W Max
Full load power consumption: 10W Max
Battery charging rate: >80%
Size: 7.7*3.7*21 inches
Weight: 11.3 ounces

Charging Time Table:
1pcs Battery Type (Ni-MH) Capacity Charging Time (approx)
AAA 500-1200mAh 1-3 hours
AA 1300-2800mAh 1.5-3.5 hours
C 1800-5000mAh 2-6 hours
D 1800-10000mAh 2-10 hours
9V 150-600mAh 5-20 hours

How to change the mode of Charge & Discharge
Press the button for charging and discharging: "CHG" -- Charging; "DISCHG" -- Discharging;
"ERROR"-- install the battery incorrectly or the battery is broken one.

Attention
* LED will not turn off when fully charged for 9V battery, please remove the 9V battery timely when fully charged.
* Please ensure the battery installed is correct: make the +/- pole of the battery is match for the +/- pole of the charger.
* Using environment: 0¡æ to 40¡æ, it is normal phenomenon that the battery is warmer than room temperature when charging.
* Do not disassemble or reassemble the charger by yourself for safety reason.

Packages
1 x 906 battery charger
1 x user manual
1 x AC adapter


NOCO Genius G3500 6V/12V 3.5A UltraSafe Smart Battery Charger

Charge fully drained lead-acid and lithium-ion batteries up to 120Ah, including ATVs, lawn mowers, motorcycles and cars. Safely maintain all types of automotive, marine, RV, powersport, lawn & garden and deep-cycle batteries..

Cutting-edge technology delivers superior performance. Charge 2x faster, repair damaged batteries and use with micro-hybrid start-stop vehicles and CANBUS electrical systems..

Streamlined design that's ultra-compact, portable and incredibly lightweight. It features external mounting holes and a rubberized base that avoids surface slipping and scratches, all while remaining impact, UV and water-resistant (IP65)..

Stay safely connected 24/7. Monitors battery activity for safe and efficient charging, automatically minimizes energy consumption and includes spark-proof technology, as well as reverse polarity and overcharge protection..

Intuitive LED indicators provide visual state-of-charge feedback and diagnostic information, even when in maintenance mode..

NOCO Genius Smart Battery Chargers are some of the safest and most advanced on the market. One of our best, the G3500 3.5A is designed to charge 6-volt and 12-volt lead-acid and lithium-ion batteries up to 120Ah. It can also effectively maintain automotive, marine, RV, powersport, lawn & garden and deep-cycle batteries. It charges 2x faster than ordinary chargers, can repair damaged batteries and is designed for use with micro-hybrid start-stop vehicles and CANBUS electrical systems. Guided by an onboard microcomputer, the G3500 monitors battery activity for safe and efficient charging, automatically minimizes energy consumption and provides redundant levels of safety protection, including spark-proof technology, as well as reverse polarity and overcharge protection. It can remain safely connected 24/7, while its streamlined design makes it ultra-compact, portable, and incredibly lightweight. The G3500 features external mounting holes and a rubberized base that avoids surface slipping and scratches, while remaining impact, UV and water-resistant (IP65). Intuitive LED indicators provide visual state-of-charge feedback and diagnostic information, even when in maintenance mode. Designed for use on 120-volt 50-60Hz electrical systems, the G3500 includes both X-Connect battery clamps and eyelet terminals, as well as a 5-year limited warranty.


EBL 12 Bay LCD AA AAA 9V Battery Charger for Rechargeable Batteries, New Released

Charging freely - Independent charging channels, can charge 1-10 pieces AA/AAA Ni-Mh/Ni-CD rechargeable batteries and 1-2 pieces 9V Ni-Mh/Ni-CD/Li-ion rechargeable batteries..

LCD Display - Smart LCD screen will indicate the whole charging process for the AA/AAA batteries and the LED light will indicate the 9V's..

Safety guarantee - Battery detection technology, automatically turn to trickle charge when batteries are full charged and worldwide voltage for 100-240V 50/60Hz adapter input..

Intelligent control - Advanced MCU control and -∆V function, over-heat and over-current protection, short-circuit protection, non-rechargeable and defective battery detection..

Biggest Save - Best product but lowest price and high efficient after sale service always here to help..

Model
EBL-999 Rechargeable Battery Charger - For AA AAA Ni-MH Ni-CD Rechargeable Battery and 9V Ni-MH Li-ion Rechargeable Battery

Convenient for using
Freely charge 1/2/3/4......10 pieces AA/AAA NI-MH/NI-CD batteries and 1 or 2 pieces 9V batteries

Safety protected
* Controlled by MCU, and using -△V pulse charging, automatically when charged full (except for 9V battery)
* Short circuit protection and reverse polarity protection
* Overheat-detection to prevent over-charging

Compatible
AA/AAA NI-MH/NI-CD rechargeable battery, 9V Ni-MH Ni-CD Li-ion rechargeable battery. ( Not For: alkaline battery)

Input and output
Input: AC 100-240V AC 50/60Hz. Worldwide voltage
Output: 2.5-3.5V DC 3.3A

How to use the EBL-999
For AA/AAA Batteries:
Can charge the batteries individual, 10 bays/slots. Easy charge 1/2/3...9/10 AA AAA batteries
LCD shows charging process. Charging - LCD will light up; Charged full - LCD will automatically turn off.
For 9V Batteries:
Can charge 1 or 2 pcs 9V Ni-MH Ni-CD Li-ion battery
LED light shows charging process. Charging - LED light will flash after 1 second; Charged Full - The LED light will automatically turn off.

Package
1 x EBL-999 Battery Charger
1 x User manual
1 x AC Adapter


Black & Decker BM3B 6V and 12V Battery Charger / Maintainer

Battery Maintainer for use on 6V & 12V battery systems. Charges 6 and 12 volt AGM, GEL and WET batteries.

Easy connection to vehicle battery using the included battery clips, O-ring terminals or vehicle DC plug.

High-frequency smart charging technology keeps batteries at optimal charge.

Automatically switches between charging mode and float mode monitoring.

Built-in mounting bracket.

The Black & Decker BM3B battery charger/maintainer features 6 volt and 12 volt charging selectivity. Use for battery maintenance, charging RVs, specialty vehicles, antique and classic cars, marine deep cycle batteries, motorcycles, lawn mowers, ATVs, snowmobiles, personal watercraft and more. Maintains battery charge in stored vehicles and battery applications. Includes three connector sets: DC accessory plug, battery clips, and battery ring terminals. Fully automatic, provides a charge when needed, stops charging when battery is fully-charged or topped-off. Built-in circuit protection guards against overcharging, reverse polarity or short circuit.


Schumacher SC-1200A-CA SpeedCharge 12Amp 6/12V Fully Automatic Battery Charger

12A Rapid Charger.

6A Charger.

3A Maintainer for Premium Charging Applications.

12 Amp fully automatic microprocessor controlled battery charger.

Automatically adjusts the amperage rate to charge and maintain batteries.

Features float mode monitoring.

Auto Voltage Detection automatically detects 6 or 12 Volt batteries.

Reverse hook-up protection with LED indicator.

This is a 6V/12V 12 Amp fully automatic microprocessor controlled battery charger for premium charging applications. With 6V/12V auto voltage detection, this charger can do 3 Amp for maintaining, 6 Amp for medium charging and 12 Amp rapid charging, with a digital display. Also has reverse hook-up protection so the unit will not operate if clamps are reversed, and float mode monitoring. Energy efficient and eco-friendly.


EBL Smart Battery Charger for 18650 AA AAA & C Size Li-ion Ni-MH Ni-CD Rechargeable Battery with iQuick Technology

Intellicharger with iQuick technology, upgraded charging speed up to 500mA, effectively charging batteries, save your time..

Widely compatible for 1 or 2 rechargeable batteries: 18650, 26650, 22650, 17670, 18490, 16340 (RCR123), 14500, 10440 Li-ion cylindrical and AA, AAA, C Ni-MH Ni-CD batteries..

Portable and travel allowed due to the charger support any DC allowed occasion like using in car etc..

MCU controlled technology with advanced "overtime" safety function which could automatically stop to charge while the battery is fully charged..

Globally charger with smart LED to show its charging progress, when 3 LED lighting together means the battery is fully charged..

EBL Intelligent Battery Charger
EBL 992 battery charger with individual charging slot for 1 to 2 different compatible batteries and the iQuick charging speed up to 500mA when charging,
more effectively to maximize the capacity of your batteries.
DC charge allowed, could be used in car and any DC charging allowed occasion. Portable and Travel suitable.
Smart LED will be better for you to know its charging progress.

iQuick Charging Technology
Input: 100-240V AC 50/60Hz DC: 12V 8W
Output:
Ni-MH Ni-CD rechargeable batteries: AA, AAA, C (1.2Volt 500mA±50mA*2)
Lithium-ion rechargeable batteries: 18650, 18490, 26650, 22650, 14500, 10440, 17670, 17550, 16340 (RCR123) etc. (4.2Volt 500mA±50mA*2)
Output current up to 500mA±50mA, it only take half of time to make the batteries to be fully than normal battery charger.

Three Charging Mode, Double Protection
* Three charging mode: (Constant Charge Current (CC), Constant Charge Voltage (CV) and Trickle Charge)
* Providing constant current and voltage, overheat-detection to prevent over-charging.
* MCU controlled technology with △V pulse charging, automatically stop charging when charged full.

Packages
EBL 992 battery charger *1
User Manual *1
AC adapter*1


Black & Decker BC15BD 15 Amp Bench Battery Charger with Engine Start Timer

Fast, high frequency technology with 3-stage charging.

One touch automatic charging; LCD display.

Patented alternator check and battery voltage check.

Start most vehicles in up to 8 minutes with patented Engine Start Timer.

Charge and maintain any AGM, GEL and WET automotive or marine 12 volt batteries.

Get back on the road in minutes with the Black & Decker 15 Amp Bench Charger. Vehicle won't start? Battery needs maintenance? Just connect the battery charger clamps to the battery terminal and press charge. The battery charger automatically does the rest for optimum performance. With fast, high frequency technology, it delivers 3-stage charging - automatically switching from fast charge, to top-off, to trickle charge. This battery charger is also perfect for motor homes, jet skis, lawn tractors, generators or vehicles that sit idle for months at a time. One of the most advanced chargers on the market, the Black & Decker Bench Charger features a digital LCD screen that displays charging status and battery status with easy to understand icons. It also includes a patented alternator check to evaluate the battery voltage under load to indicate if the alternator is maintaining battery level. Even if the cables are connected to the wrong terminal, the screen alerts you. While many other battery chargers require you to select various settings like battery type and size, the Black & Decker 15 Amp Bench Charger is fully automatic and chargers up to 40 percent faster than other conventional chargers. Need to get back on the road quickly? The charger also features a patented Engine Start Timer to boost your vehicle battery in approximately 8 minutes. The built-in cord and cable wrap and clamp storage makes the charger easy to use and store. 100 percent CEC compliant and ETL Certified for performance and safety.


Extreme Max 1229.4000 Battery Buddy Intelligent 6V / 12V Battery Charger / Maintainer

Designed for long-term off-season storage in all climates for boats, ATVs, PWCs, UTVs, motorcycles, cars and more.

Four intelligent charging modes: Initialization, Bulk Charge, Absorption, and Float.

Charges all large and small 6 and 12 Volt lead-acid and flooded or sealed maintenance-free batteries.

1-year warranty.

*Note: Features a regulatory internal safety circuit, will not charge batteries with a voltage below 3 Volts..

The Battery Buddy Charger / Maintainer is the smartest little trickle charger around. It knows your battery has needs. Battery Buddy gets that and delivers the goods. Its built-in battery brain controls a precise 4-step power program (initialization, bulk charge, absorption, and float modes). Just connect the charger and come back when you're ready to use the battery. While you're away the Battery Buddy will be carefully calibrating its output to your battery, maintaining a full charge without overcharging the battery. If your battery slips below a full charge, Battery Buddy resumes a normal charging cycle. Battery Buddy works for batteries in cars, boats, ATVs, UTVs, PWCs, RVs, motorcycles and any other vehicle in long-term off-season storage in extreme heat or cold. Battery Buddy is uniquely designed to weather the extremes of off-season storage and take care of your battery. Intelligently designed for safe, effective charging of any size battery from big bus to small scooter. Battery Buddy features a waterproof design with a single LED status indicator light that draws almost no current, spark proof connectors, 8-foot output cord, short circuit and reverse polarity protection. 1-year warranty. *Note: If you try to charge a dead battery having a voltage below 3 Volts, the Battry Buddy will not start to charge because an internal safety circuit prevents the battery cahrger from generating any DC output voltage at that level. If a 12 Volt lead-acid battery has an output voltage of less than 9 Volts when at rest when it is neither being charged not supplying electrical current to an external load, there is a good chance that the battery is defective.