I thought the chargers need to know the total number of cells and total pack voltages to charge, since they have no way to communicate to know when to stop.
So I can get the chargers first and then power tank afterwords?
yup. I did read about something regarding, that it is better to have a power tank installed as soon as possible. This because of the aging regarding the battery of the power tank, and the battery in the bike. It sounds sensible, but in theory I do not think it really matters.
I mean, it is probably better. But you can get away with it if you do not do it.
Battery chargers usually work as follows:The plus and minus of the battery is connected to the plus and minus of the charger. By doing so the charger is able to measure the voltage of the battery.
Good chargers are able to regulate at least two things; Voltage and Current. After sensing the voltage the charger tries to increase the voltage of the battery. When the voltage is increased, the battery will draw current from the charger.
By regulating the current, the charger is able to create a charge curve. Some batteries require these.
In order for the charger to ensure the batteries are not over charged, it needs to know the maximum voltage of the battery.
When while charging the maximum voltage is reached. The charger stops increasing the voltage and the charging automatically stops.
Three more points to know:
- Chargers are only able to deliver a limited amount of current.
- Our batteries also need battery balancing. In our case this is handled by the BMS (it does way more than this tho)
- Our batteries have a Contactor(a main power switch). This needs to be turned on to charge. Our OBC's tell the bike that it is in charging mode and asks the BMS to turn on the Contactor.