Charging a 6-volt battery is no different than charging other voltage batteries, but you do need to ensure that you are using the correct charger. For example, a 6-volt lead-acid battery, such as the type sometimes used in marine vessels or RVs, needs to be charged using a suitable lead-acid charger. A nickel or lithium-based battery, such as those used to power cordless tools, must be charged using a charger designed for the correct chemical base.
Step 1 Ascertain the chemical base of the 6-volt battery. It is clearly labeled on the battery and will say LA or SLA if it's a lead-acid battery, NiCd or NiMH if it's a nickel battery, or Li-Ion if it's a lithium battery. Make sure you have the correct charger for the type of battery you need to charge.
Step 2 Attach the battery cable clamp on the end of the red wire from the charger onto the "+" terminal of the battery and the cable clamp on the end of the black wire from the charger onto the "-" terminal of the battery, if your 6-volt battery is lead-acid.
Step 3 Insert your battery into the charger, if the 6-volt battery is nickel or lithium-based. Simply insert the battery into the charger compartment, ensuring you match the "+" and "-" terminal on the battery to the corresponding "+" and "-" terminals on the charger.
Step 4 Set the charger to charge at 6 volts, if it has a variable charge feature. This applies to both a lead-acid charger and a nickel or lithium charger. Charging at a higher rate can damage your battery and may be dangerous. Charging at a lower rate doesn't cause any damage, but it will take considerably longer for your battery to charge.
Step 5 Turn on your charger. Make sure the charge light indicator illuminates to confirm charging is in process.
Step 6 Leave the battery to charge. The charge light turns off or changes color once your nickel or lithium-based battery is fully charged. However, lead-acid battery chargers continue to charge until you turn them off. You can expect to charge a 6-volt lead-acid battery in a couple of hours using the normal charge setting. If you use a boost charge, then an hour is usually fine; but if you use a trickle charge, leave your battery to charge for about 6 to 12 hours and then turn off the charger.
Remove the battery from the charger, if your battery is nickel or lithium-based. Remove the cable clamps attached to the two battery terminals, if your battery is lead-acid.
Items you will need: Battery charger (suitable for the chemical base of the 6-volt battery)
