Sealed lead acid batteries are widely used but charging them can be a complex process as tony morgan explains. To achieve the criteria for balanced charging you simply need to start one of the charging leads from the opposite direction.
Battery Basics Progressive Dynamics
Charging batteries in parallel lead acid. In this example each battery will draw current through exactly three interconnecting leads. With no resistance to slow this charging process the charged units can overheat as they rapidly drain and the discharged battery can overheat as it attempts to charge at well above its design. For example if charging one battery normally takes three hours and you have five batteries linked in parallel the charging time will be five times three hours or 15 hours. This varies somewhat depending on. The correct method to charge batteries in parallel balanced charging. Multiply the time anticipated to charge one battery by the total number of batteries.
Each battery must be in a state where it can be voltage charged. In theory it is ok to connect them in parallel with two conditions. A regulated current raises the terminal voltage until the upper charge voltage limit is reached at which point the current drops due to saturation. If you connect rechargeable batteries in parallel and one is discharged while the others are charged the charged batteries will attempt to charge the discharged battery. The charge time is 1216 hours and up to 3648 hours for large stationary batteries. The coulometric charging efficiency of flooded lead acid batteries is typically 70 meaning that you must put 142 amp hours into the battery for every 100 amp hours you get out.
Charging sealed lead acid sla batteries does not seem a particularly difficult process but the hard part in charging an sla battery is maximising the battery life. Very discharged lead acid batteries have to be charged with fixed current until they get to a minimum voltage then they can be voltage charged. Simple constant current constant voltage chargers will do the job for a while but the battery life expectancy quoted by the manufacturer will be greatly reduced by using non intelligent chargers like this. Into account that the battery charging voltage is higher than the battery discharging voltage. This is fine for lead acid batteries unless they are very run down. The lead acid battery uses the constant current constant voltage cccv charge method.
For secondary rechargeable batteries the stronger battery would charge the weaker one draining itself and wasting energy.
Gallery of Charging Batteries In Parallel Lead Acid
