Battery doesn't charge

How old is the battery? In general, vehicle batteries are considered 'old' after 5 years especially on bigger engines.
Using a volt meter or a multimeter set to Volts try this. With the engine off and the Keys out test the voltage directly on the battery. You should get a reading somewhere around 12.6 to 13.2 volts. Start the engine and retest the battery voltage. If the alternator is working correctly the reading should rise to somewhere around 13.6 to 14.2 volts.

Question edited for clarity.
Question moved from Cars and Trucks.

Lithium Ion batteries are not suitable for motorcycles despite what it says on the label and advertising. The Scotty Kilmer YouTube Channel did a video on it 2 says ago! The technology is different the maker did not design the electronics and the computer for Lithium Ion.

Its better u take it to a motorcycle service, they can check the voltage that the scooter produces to charge the battery, maybe its the regulator or the magnetic field.

Due to the nature of the battery technology used with vehicles the alternator is mostly incapable of charging the battery. The car alternator is designed to keep a fully charged battery fully charged and to provide all the power for the car equipment.

The alternator charge rate is regulated by a voltage regulator. Because the alternator output is connected to the battery, the alternator and battery voltage will be the same and the voltage regulator monitors that voltage.

The lower the battery voltage the more output the alternator will produce in order to correct the situation but because a lead acid battery has a high internal resistance to accepting a charge the terminal voltage will quickly rise to the alternator regulated voltage and fool the alternator into thinking the battery is fully charged when the output will drop to the order of just a couple of amps.

Switch on the headlights or a similar load that will lower the battery voltage and the alternator will increase it's output again - but only by the amount of current the headlamps or other load is consuming.
It matters not what the alternator rated maximum output is, it is designed to provide only the necessary current and no more.

The only time an alternator should ever need to produce maximum output is when on a dedicated testbed and then only for a short duration to avoid damaging the unit. Testing the current output on a modern vehicle is not recommended except for the regulated voltage testing and a rule-of-thumb output test where all equipment is switched on and the engine speed raised while the battery voltage is monitored.

Most modern alternators use an internal voltage regulator but a few systems use a separate voltage regulator. No alternator rebuild would be complete without a regulator test and probably a new or replacement regulator, which is where the majority of charging system problems are, or the brush gear.
Assuming the wiring is ok, no alternator should suffer any harm if the voltage regulator and auxilliary diodes (if fitted) are in good order though fitting a defective or a discharged battery can cause it to overheat and be damaged.

The alternator usually just about stops producing an output when the battery voltage is in the region of 14.5/14.8 volts.
Your description indicates the voltage regulator is not working correctly - unless 40 amps was being consumed by the car equipment the alternator should not have been producing 40 amps.. I suggest you also have your battery tested

This is just a suggestion, but some Dell Computers use an AC adapter which sometimes power the computer but do NOT charge the battery pack.

Simply trying another different power supply or AC Adapter will fix the problem without changing the voltage regulator.

I hope this corrects your problems.

Good Luck and regards from:
Richard, Montreal Based Panasonic Canada Toughbook Authorized Dealer since 1989.

You are misunderstanding the manual. There is a voltage regulator and it is part of the engine computer. When the regulator goes bad, you need to replace the computer. Its a really bad design but that's the way it is!!! There is a "work around" involving bypassing the computer and installing an external regulator but it turns the light on and won't pass inspection that way.

If you have a voltage meter, you should check if your voltage regulator is working correctly. The voltage regulator should keep the voltage to the battery something under 15 volts when the motor is running (more than 13.5 volts with all electrical turned off).

If more than 14.5 volts, you may be damaging your new battery and regulator is not working properly. Also, radio may not come on because a voltage sensor is protecting it from the high voltage. Antenna is controlled by radio so that should not be working either.

Good luck.

first of all check the voltage across the battery with the bike running,it should be between 13.2 and 14.5 volts,if it is not then there is a good chance that either your alternator or generaator need new brushes or by your description hane the voltage regulator checked or replaced,if this is not working correctly you will not charge the baateery,hope this helps

I hope you got this problem fixed, just happened to my predator, it was indeed the voltage regulator. I picked up a service manual that includes part numbers and installation procedures from www.promanuals.net for 15 bucks.

Check your conections at the batery and at the selonoid. It could also be your voltage regulator or the generator, the repair manual should tell you how to test them.