V-mount batteries are professional-grade power solutions commonly used in broadcast and cinema equipment. These lithium-ion batteries feature a distinctive V-shaped mounting system and typically range from 95Wh to 290Wh capacity. The charging process involves sophisticated battery management systems (BMS) that monitor cell voltage, temperature, and current flow.
The issue of V mount battery not charging can occur during your filming process. What causes this problem, and how can you fix it? In this post, we’ll cover both the causes and the solutions.
Battery over-discharge protection
Modern V-mount batteries are equipped with integrated protection circuits that guard against over-discharge damage. If the battery is fully drained, these safety features may block charging until the battery is "reawakened" or reset.
🔧Solution: Keep the battery plugged into the charger for several hours, even if there are no immediate signs of charging. Some chargers feature a built-in “wake-up” mode specifically for reviving deeply drained batteries.
Charging limitations due to temperature
Lithium-ion batteries charge best within a specific temperature range—usually between 0°C and 45°C (32°F to 113°F). If the battery is too cold or too hot, it may not charge as a built-in safety precaution.
🔧Solution: Let the batteries reach room temperature before charging them. Whenever possible, store the batteries in environments with controlled temperatures.
Charger fails to recognize a fully depleted V mount battery
Many modern or “smart” chargers rely on detecting a minimum voltage to identify the battery and apply the correct charging current. If the battery is fully drained to zero volts, the charger may not recognize it. In such cases, supplying a brief initial charge can help the charger detect the battery and begin normal charging.
🔧Solution: There are two ways you can try.
A "dumber" charger might work. If you're dealing with a fully depleted battery, a simple charger without microprocessor control—often called a "dumb" charger—might help revive it. Connect the battery for about an hour to give it a small initial charge. Then switch to a smart charger to see if it can now detect the minimum voltage and continue with a full charge. Use caution and monitor the process closely.
Connect it to a fully-charged battery. In some cases, you can try to revive a non-charging Li-Ion battery by briefly connecting it to a fully charged one. For V-mount batteries, this may require a custom cable that links the two batteries via their D-tap ports.
⚠️Warning: This method carries a risk of damaging both batteries, so only attempt it after trying safer options.
Real-world example
One Moman Power 99 user shared their experience:
I had a dead MOMAN 99 battery and noticed it has two D-tap ports. I connected my camera (with its own battery) to one port and the charger (which previously showed a green light—indicating no charging) to the other. The charger light started flashing green and red. After unplugging everything and reconnecting only the charger, it began charging normally. This may help give your battery the kickstart it needs.
V mount battery aging and cell wear
Over time—typically after 300 to 500 charge cycles or several years of use—the battery cells degrade. This leads to higher internal resistance and a decreased ability to hold a charge.
🔧Solution: It may be time to replace your battery if you notice the following:
- The battery no longer holds a charge for as long as it used to
- Charging issues persist even after trying all fixes
- There are visible signs of damage, such as swelling or cracks
- The battery becomes unusually hot during use or while charging
- It’s been in regular use for over 3–5 years
Incompatible V mount battery charger
V-mount chargers can vary significantly between brands. Charging failures often occur when using a charger that doesn't match the battery's requirements. Manufacturers may implement different voltage levels, charging methods, or communication protocols, leading to compatibility issues.
🔧Solution: Always use the manufacturer-recommended charger or verify compatibility specifications before using third-party chargers.
Faulty charger or cable
Issues with the charger or cable may prevent the battery from charging. Problems such as loose connections, damaged cables, or a faulty charger can obstruct proper charging.
🔧Solution: Before exploring other potential issues, rule out hardware problems first. Make sure the V-mount battery is securely connected to the charger. Test with a different certified charger or cable if available, and observe the LED indicators for normal charging signals (such as a solid red light).
Damaged or dirty charging contacts
Charging may fail if the contacts between the battery and charger are dirty, corroded, or physically damaged. Even slight corrosion can interfere with the connection.
🔧Solution: Use isopropyl alcohol and a soft cloth to clean the contacts. Check for any physical damage—if the contacts are severely affected, consider replacing the battery or charger.
Proper charging is crucial for extended lifespans. Check the post to learn how to charge V mount battery properly.
