I recently read about a very clever and small device (powerplug) that, in order to save the battery condition of an ebike and extends its lifecycle, is able to monitor the power consumption while charging the battery and switches it off on a certain percentage (80..90% of full capacity).
This prevents from batteries getting (too) warm during the charging process preventing possible fires due to overloading, but it also results in a longer lifecycle when batteries are not charged upto 100%.
This should also be easily possible using a Homey flow using a smart powerplug with power/energy monitoring, but maybe/possibly someone has already looked into this.
I doubt that a device that simply monitors power going to the charger will reliably determine the state of charge of a battery since charging efficiency is dependent on a number of factors. I guess the best it can do is spot when the charger starts to reduce its charge rate as the battery gets close to its limit. You could probably use a power plug with energy monitoring to emulate such an approach.
Some bike systems use standard protocols to broadcast battery information. My Mahle system uses ant+. If you could find a way to get a signal into Homey, that would be a much better approach. I don’t see an app for that, and it might be that Homey’s radios can’t work with ant+.
FWIW, if you are using a battery and charging system from a well-established retailer, the risks associated with charging are very low. They will automatically reduce charging levels as the battery charges. We are all used to charging a wide range of devices in the home and we don’t expect them to burst into flame. Car batteries absorb much greater energy but, again, present a very low risk. The greatest risk from charging eBikes is poor quality batteries and charging systems associated with ‘knock off’ bikes - they’re cheap because they cut corners.
FWIW, I don’t charge my bike after every ride. Instead, I decide before each ride whether I need to recharge for that ride. If I do, I usually recharge to 100%. That approach minimises the number of charge cycles and means I don’t store the batteries for long at 100% - which is not great for the battery, but I don’t see it as a safety concern.
Ideally, of course, bike manufacturers would give us the option to charge to a given percentage (like Windows laptops do).
Andy
