Charger is broken :(

[MrBump]

Just a flashing red light from the charger and it's not charging the unicycle - I'm guessing it's borked.

I figure these chargers can't *just* be made for electric unicycles and I'd rather not wait for banggood to ship another from half-way round the planet.  Any ideas on where to find an equivalent charger that I could get more quickly - don't want to be without my wheel for weeks.

 

 

[Gimlet]

I've seen them on ebay occasionally and there are a few suppliers of high quality faster chargers on this group.

[MrBump]

Cheers - I've just ordered another and paid for faster shipping.  Do you know whether faster chargers have a bad effect on battery life?

[esaj]

Cheers - I've just ordered another and paid for faster shipping.  Do you know whether faster chargers have a bad effect on battery life?

This might help: http://batteryuniversity.com/learn/article/ultra_fast_chargers  Fast charging is said to have at least some effect on battery aging, but if you don't go overboard, it shouldn't have that much effect:

In general, with high quality cells, 1C charge rate shouldn't be a problem (http://batteryuniversity.com/learn/article/what_is_the_c_rate), although I think the manufactures rate some cell-chemistries at higher rates. Simplified, C-rate means the number of amperes used in charging (or discharging) in relation to the battery capacity. So a 2000mAh (2Ah) battery charging at 2A is charging at a rate of 1C, and should be fully charged in 1 hour (although in reality, the charger starts to drop the current towards the end of the charge, so probably takes a little longer).. 4A charging for similar battery would be 2C (should take about 30 minutes), 1A charging would be 0.5C (should take about 2 hours). If you have multiple packs, the charge / discharge current is divided among the packs. If you know their Ah- or Wh-capacity, you can calculate the amperage for 1 hour charge/discharge (1C) pretty easily:

Battery amp-hours per pack * number of packs / 1 hour, but you can leave the division by 1 hour off (divided by one). So for example, two 2.9Ah (2900mAh) packs that would be 2.9 * 2 = 4.8A

Or   (Battery watt-hours per pack / nominal voltage) * number of packs / 1 hour. For example for four 132Wh packs at 60V voltage, 1C rate would be (132 / 60) * 4 = 8.8A, for one pack it would be 132 / 60 = 2.2A. That's a pretty high current with the four packs, so another thing to take into account with fast (= high current) charging is that thinner wires can heat up considerably under high current for a longer time, as may the connectors, also the BMS(s) can limit the maximum current. You don't want to melt the wiring or burn the connectors with too much current   When 1Rad Werkstatt was selling the >1kWh packs for MSuper, they were also selling a separate fast charger (8A), but said it shouldn't be used with normal MSupers, as the charging port (or maybe it was some other connector in the way between the port & packs) wouldn't withstand that high current.