LeBouc
XS400 Enthusiast
Hello Elder (I am 70 so I also consider myself an elder). I have checked your battery at BatteriesPlus and read a very interesting comment that could explain your problem. You said it's a Smart battery; the BMS (battery Management System) that comes with your battery is probably the reason of your charging issue. When it senses a voltage higher than what the lithium battery can accept, the BMS protects the battery by simply cutting the incoming charge! Since our alternator punch out as much as 14+ volts and the lithium batteries will not tolerate more 12.5 (or 12,8V, I don't remember - old age memory!), the BMS blocks the charge. The battery is still connected to the bike and will empty itself to satisfy the needs but there is no recharging. When you read about lithium battery charging, they will tell you that you need a specific charger for them. On our bikes, you would need to put (yes, again) a voltage regulator specifically built for lithium batteries (don't stop reading yet). By the way, your LEDs will last a lot longer if they are fed at around 12V rather than the 13-14V that comes from the charging system so it could save you some money to connect them to that regulator as well. However, since Watts = Volts X Current, the LEDs will not shine as much... The other parts on your bike, like the CDI, are designed to work with the voltage regulator that comes with the bike but can probably continue to work without problems with 12.5 Volts. The ignition coils, however, will produce a weaker spark because they will receive less energy . So I suggest that you connect only the lights and the battery to the voltage regulator for lithium battery and keep the rest connected to the standard one. This is my last post on this topic. I have used my own time to help and if you don't like what I say, it's useless to repeat myself. So good luck with your project and enjoy your bike!
