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Charging system quick check
According to this your charging system is not working.
This is from the YUASA BATTERY TECHNICIAL MANUAL Available on their website.
Charging System Quick Check
A quick check of a powersport vehicle’s charging system can be
performed using a digital voltmeter. Connect the voltmeter leads
directly to the battery (red to positive and black to the negative
terminals). Read the open circuit voltage and start the engine.
Operate the engine between 3000 to 4000 rpm while watching
the reading on the voltmeter. If the vehicle’s charging system
maintains voltage between 13.0 and 14.5 volts, the charging
system is probably working properly. If voltage is the same as
open circuit voltage (usually less than 13 volts) the charging
system is not working and further diagnosis will have to be
performed. Installing a new battery in a powersports vehicle with
a faulty charging system will eventually result in a dead battery
and an unhappy customer. Always use the OE service manual as
a guide for further testing and diagnosis of the charging system.
This wont help you with the engine open but I'm adding it for other people.
Battery Load Testing
Once the battery is charged and passes the open circuit voltage
test its time to determine if it can really perform its main job—
starting the engine. It might seem obvious that if the starter
button is pressed and the engine starts, the battery must be
OK. While a marginal battery might start an engine a few
times, it may not reliably start it in the future—especially in
There are two tools that can be used for load testing: a dedicated
battery load tester, or a digital voltmeter. The load tester can
be used when the battery is not installed in a vehicle. The load
tester simulates the electrical load of a starter motor to load-
test the battery. These testers are usually used by dealerships
and are able to adjust the load applied to the battery under
test. Always follow the instructions that apply to the specifi c
battery load tester. In general, apply a load of three times the
ampere-hour rating. After 10 seconds check the battery voltage
with the load still applied. A good 12-volt battery will not drop
below 9.5 volts (ambient temperature of 70° F). A 6-volt battery
should drop no more than 5.25 volts. If the voltage reading is
below these minimums replace the battery.
As an alternative to the load tester, the vehicles starter
motor can be used to provide the load to test the battery.
To load test the battery, cranking voltage must be measured.
Low cranking voltage will indicate that the battery is getting
tired and should be replaced. Following are the steps for
performing a battery load test using a digital voltmeter and
the vehicle’s starter motor.
Connect a digital voltmeter directly to the battery—red lead
to the positive terminal and black lead to negative. While
watching the voltmeter, press the start button and crank
the engine’s starter (it’s OK if the engine starts). Just before
the engine starts, note the voltmeter reading. As the starter
motor places an electrical load on the battery, cranking
voltage will normally drop. If battery voltage drops below
9.5 volts (at 70° F) while the engine is cranking over,
the battery needs to be replaced. If the engine starts too
quickly to read cranking voltage, the ignition or fuel injection
computer fuse can be removed. This will allow the starter
motor to operate (without the engine starting) and cranking
voltage can be measured.
The grass is always greener . . .
Last edited by gyrotumbler; 09-05-2015 at 12:10 PM.