ive been having a bit of an issue with my freshly purchased 01 250. today i checked the resting voltage and the running voltage of the bike, then i checked out what the voltage does with the headlight on high and with the turn signals.

im trying to figure out how high the stock charging system should be. can some of you fair ninjette owners go outside with your voltage meter and report with the voltage you see?

(i have checked the FAQ already)

thanks in advance

around 13.6 V if I'm correct. what are you getting?

im landing around 14.8, which i would consider good with a car.
the battery that i have in the bike is a SLA sealed lead acid, meaning it has a lower internal resistance, which usually will have an alternator in a car do a bit more voltage.

The following is a cut-and-paste from the ninja250.org FAQs. I think it explains why you're seeing 14.8-ish when you check your system. Also, it shows that it's perfectly normal.

There are four basic pieces to the charging system. These are the Stator, the Reg/Rec, the Battery, and the wiring that connects the three. The stator is under the left engine cover and turns with the crankshaft. It's made up of 2 pieces: the stator itself, which is a bunch of wire loops, and some magnets. As the wire passes in and out of the magnetic field it generates an AC electrical charge. This charge is fixed, and is a 3-phase in most bikes (meaning the stator has 3 individual wire loops, all making a charge). That AC runs up to the Reg/Rec.... or Regulator/Rectifier. This does just as its name implies: it rectifies the alternating current into DC, and regulates it down to a maximum of about 14.7 volts DC. The reason the AC must be converted to DC is because you can't store AC voltage in a battery, only DC.

As a side note, an alternator works on a similar principle, except the regulator controls an electromagnet (increasing and decreasing its magnetic power) to limit the power output, instead of shunting the excess to ground as heat.

The Reg/Rec then lets the power flow to the battery. If any one item in the system is bad, it can, and eventually will, damage the other items. This is the main reason it's so important to keep the system in good shape - it can be expen$ive to replace everything. Most often, though, the wires take the brunt of the failure and cook themselves. They then gain resistance (heat = resistance) and make everything work that much harder, which is an unnecessary stress.

thanks for the page.

I read a different one on there that said 13.6 for top charging voltage.

I just need to figure out if this battery is toast or not.

anywhere within those ranges are ok.. u shouldnt be worried.

I know when I tested my system when installing bulbs into the empty brakelight pods I was getting about 14.6 on my 2007....

what has happened so far since ive been riding the last 5 days in a row is that the battery will start the bike for the 1st warm up, but if i turn the choke down too fast and it dies, i have to jump it.

i imagine that at this point, i need to get it almost warm and kill the bike myself and see if there is enough juice to restart it.

how old is your battery? they don't last forever. :)

i just bought the bike in december the last owner got the battery last summer or the one before. its sealed, so no adding fluids

What dies? The battery dies or the bike dies? What is the voltage at the battery if you go test it, then turn the bike on with the headlight on? If it drops a lot, your battery may not be charged fully, have little amp capacity. Does the bike start when you jump it from another battery. like from your car?
(Do NOT try to jump the bike from a car with the car's engine running - the output of the car's alternator will fry all the electronics on any bike.)
Put the battery on a charger overnight for starters.. If you're getting 14.8V when you start the bike now, the battery may need a good charge. When it's fully charged you may read the 13.8V instead with the bike running.
The only way to know if a battery if any good is to fully charge it and then put it on a load tester. Any battery store or Walmart or Autozone or places like that will test it for you. A battery can read 12.8 V and be not good. If you do buy a new battery, an AGM, make sure you CHARGE IT FIRST before putting it into service, before first use, or it will start the bike a few times and die. It will never again charge up to it's full capacity.

i just bought the bike in december the last owner got the battery last summer or the one before. its sealed, so no adding fluids

if the bike was left to fully discharge and recharging the battery was the only way to get life back into it, your battery may be toast. Batteries do not like being neglected and life expectancy can be compromised.

I'd say your charging system is fine if your battery reads higher when the bike is running than when not.

my suggestion is to have the battery load tested as suggested or just replace it if they are relatively inexpensive for peace of mind.

thought today about having it load tested. good call guys

it is a deep cycle style battery, so if it has been taken to full discharge, it should live again.

i may just buy a battery so i feel better about it before taking a 400 one way trip next week.

im going to ride it to work tomorrow and see how it goes. i hope i dont have to find a jump after work

I just bought battery at Sams club $25 bucks if remember.. It was bigger old style & had to put connect to the rear but works fine.

i ended up buying piece of mind and getting an all new battery yesterday. After riding just 2 full tanks out, i will have saved what i would have paid for the same miles in my Dakota.

There is a big difference between a starting battery and a deep cycle battery, relating to the power output. A deep cycle battery that small may not be able to put out the amps all at once to start your bike, whether the battery is fully charged or not. I hope you got yourself a good STARTING battery.

Its an AGM totally fine. in testing it took over 200 amps draw and stayed over 11v. The bike is running great now. Now that everything runs well, its time to get into changing oil/coolant and checking out the chain.

Glad to see you've got the battery issue sorted out now. An easy and useful modification is to install a Datel voltmeter. I put one on my 2005 about two years ago. Here's a "how to" writeup on installing one.

http://faq.ninja250.org/wiki/Installing_a_voltmeter

My installation looks just like the one on the silver fairing bike.

good idea. i have a Stinger digital meter laying around that i could put on there.

I actually have years of experience doing car audio competitions where I used to have to have a bank of batteries to handle over 5000 amps of current draw for 5 seconds without loosing much voltage. unfortunately on the bike, there is no room for a bank of 64 8 volt batteries :)