Transcript
24V ELECTRONIC ACTIVE LEAD ACID BATTERY BALANCER
2017 Mi
EBB24V
24V Electronic Active Lead Acid Battery balancer for series connected Battery packs Background: Sometimes higher voltages than 12v is needed and the user have to wire batteries in series to get the desired output voltage. This creates uneven battery voltages in a short time because of the different internal resistance of each individual battery in the series stack. One of the batteries will charge quicker based on internal resistance within the battery being lower than the other, resulting in uneven charge as one battery will always charge to a higher voltage than the other causing unbalanced charge between the two batteries which leads to shortened life span of series connected batteries over parallel connected batteries. The series connected stack capacity will be only as good as the lowest battery in the series stack and equal to the Amp/hour capacity of the lowest(under charged) Battery , thus the series battery pack never reach full stack capacity if the batteries is at uneven charge and voltages.
24V ELECTRONIC ACTIVE LEAD ACID BATTERY BALANCER
2017 Mi
Through connecting Batteries in parallel – Battery 1 will either charge or discharge to Battery 2 depending on the state of charge of battery 1 until both batteries have the same voltage because of the direct parallel connection. B1 and B2 will always share current to keep both in the same voltage condition.
The EBB24V was developed to electronically balance the batteries in a series connected stack through the use of one extra Auxiliary Battery electronically connected in sequence in parallel to each battery in the series stack until battery voltages converge. Solution:
The EBB24V will connect the Auxiliary Battery in parallel to Battery 1 in the series stack, either charging from or discharging to Battery 1, an internal 8 sec timer is started, if the Auxiliary Battery and Battery 1 reaches the same voltage within the 8 sec the sequence is discarded and sequence 2 will follow, otherwise it will keep the Auxiliary battery connected to Battery1 for the 8 sec period where after sequence 2 will follow. In sequence 2 the same Auxiliary Battery is connected in parallel to Battery 2 in the series stack again charging from or discharging to Battery 2 and the same sequence follows for 8sec or until the Auxiliary battery and Battery 2 voltages converge, sequence 1 is started again. This operation will continue while the series Battery pack is charged or being discharged.
24V ELECTRONIC ACTIVEE LEAD ACID BATTERY BALANCER
2017 Mi
Through connecting the auxiliary battery in parallel and in sequence to each battery in the series stack the battery voltages ages will converge after time ensuring each battery in the series stack is evenly charged thus ensuring full stack capacity and longer battery life expectancy for series connected batteries.
The capacity of the Auxiliary cell is not lost or wasted for balancing lancing only as the system continuous to try and keep the battery voltages equal by discharging into the series stack batteries while discharging the series stack in the event of a power failure and no charge source is available. The auxiliary battery thus adds Amp/hour capacity to the series battery stack. Disconnection voltage of the auxiliary battery from a series stack battery in sequence 1 or 2 will occur once the difference in voltage between the batteries is 0.2 V apart apart. 12V lead acid batteries consists of 6 internal cells, leaving aan unbalanced voltage of maximum 0.2V /6 = 0.03v per cell. It is also important to install the EBB24V as close as possible to the series battery pack and auxiliary battery and to keep cables as short as possible to p prevent revent voltage drops along the cables to a minimum. The EBB24V is protected by 7Amp electronic self resettable fuses on each input from the series stack batteries, current is limited for charge and discharge between the series stack and the auxiliary battery by means of a ceramic PTC, the PTC will quickly iincrease ncrease resistance if large current flows between the batteries and protect the Mosfet switches by reducing the current flow.
24V ELECTRONIC ACTIVE LEAD ACID BATTERY BALANCER
2017 Mi
Led indication and wiring On board led’s PTCFLT on = PTC tripped and resistance increased to limit current flow – self resettable DONE on = the 2 batteries in the series stack is within 0.2V from each other, pack balanced BAL on = The balancing operation is active UVFLT on= one of the batteries in the series stack is below the low value setting of the board, the EBB24V will keep trying to recover the battery and balancing will continuo OVFLT on = one of the batteries in the series stack is above the high value setting of the board, the EBB24V will keep trying to recover the battery and balancing will continuo SEQ on = Battery 2 is being balanced SEQ off = Battery 1 is being balanced
Connections and startup: 1. Connect the Auxiliary battery – makes sure about the correct polarity connection 2. Connect the series battery pack GND 3. Connect the centre tap between the 2 series batteries to +12V terminal 4. Connect second battery 24V output to +24 terminal
