Brand new battery dead??! - Honda RC51 Forum : RC51 Motorcycle Forums

lhvRC · 06-10-2011, 07:31 AM

Ok guys i need some help, so i bought my RC 4 months ago it came iwth a semi good battery, so i recharged and it lasted about month, after it died i got a new one($115) after two months of riding BAM its dead again. IT does the same thing, week prime sound, tryes to crank but wont, so i jumped it with my car, started up instantly. So i let it run for about 30 minutes, took it for a short ride, turned it off, then tryed to start it instantly after, same problem wont start. ITS A BRAND NEW BATTERY, the shop already said they would give me a nbrand new battery but before i try that and anotehr one bites the dust is there anything else i can check out just incase its not a random faulty battery? Suggestions please, thansk guys

**SubSailor** · 06-10-2011, 11:40 AM

Make sure your battery posts connectors and ground cable connection is clean and tight.
Check your charging voltage output.
It should at lease 13.5V but not over 15V.
If the output is too low, you could also check the stator coil resistance to see if a coil is open or shorted.
Also you could do the current leakage check in case there's a short somewhere.
The battery is new, so there shouldn't be any leakage internally.

lhvRC · 06-10-2011, 12:47 PM

checked the connections,e verything is good clean and tight, to be honest ive been riding for 8 years, never been around workign on bikes, what and where is the strator? and how would i check the charging voltage? thanks man.

**SubSailor** · 06-10-2011, 09:29 PM

Get a decent digital multimeter that also measures amps, then place the probes across the battery posts.

With the engine running at say 4000+ RPM, you should be getting at least 13V or more, but not more than 15.5V.
If you're not getting 13V, you may be having either a stator problem or rectifier/regulator problem.

The stator is the part of the alternator where current is produced.
The RC51 uses a 3-phase alternator which is rectified to DC, then regulated to required voltage range.
The regulator/rectifier is the finned module on the left subframe area.
The stator cable connects to it.

By referring to the service manual, you use the resistance measurement portion of the multimeter to measure resistance of each stator coil, plus each coil to ground.
Each coil should be around .2-.5 ohms (although mine measures .6 ohms with no problems).

If a coil is below or above the required spec, the coil may be bad.
If you measure a coil to ground and it does not show an open, then you have a shorted stator coil.

If a coil is out of spec or is shorted to ground, you'll have to replace the stator assembly.
If the stator checks out and your battery charging voltage is out of spec (too low or too high), then you may have a bad rectifier/regulator module.

If the charging voltage is in spec and the stator checks out, you can perform the leakage current test on the battery.
If the current leakage is greater than .1mA, you may have a short in the wiring somewhere.

It's all in the service manual. The PDF version is here if you don't already have a paper copy.
http://www.rc51.info/index.php?page=service

gts455 · 06-10-2011, 10:54 PM

Also if you have a quick battery connection....the kind that sticks out under your seat for a quick plug in to charge on a trickle charger, they sometimes drain the battery.

Becareful jump starting the bike with a car. it's possible to damage the battery, or even fry your kill switch.....although its rare.

lhvRC · 06-13-2011, 06:54 AM

Thanks a ton guys, given my busy weekend i didnt get to check anythign yet, but i will this afternoon, and keep everyone updated. If anyone in the area wants to lend me a hand i can provide some bbq and brews this week.

MorpheusRS · 06-13-2011, 07:44 AM

i'm having the same problem, just got a new batt.. testing it out. as the voltage is in spec..

lhvRC · 06-14-2011, 07:01 AM

Quote:

Originally Posted by MorpheusRS

i'm having the same problem, just got a new batt.. testing it out. as the voltage is in spec..

Keep us all updated on the progress, didnt get a chance to do anythign with mine. The shop that sold me tha battery said they fired the guy who sold me my battery becuase he gave me the wrong one lol, awesome! haha so they are giving me a new one for free, so after i pick it up then i will be doing some testing.

gts455 · 06-14-2011, 09:10 PM

....wow. thats pretty bad.

lhvRC · 06-20-2011, 01:05 PM

Tried to get to the bottom of the problem, couldnt find anything. The shop couldnt take look at the bike until mid july..FML.... so on Saturdays its first come first serve for inspections, so i jumped the bike knowing it wouldnt start up and went ot have it inspected, left them with the key and they were forced to look at it haha, i know kinda shady but it was my only option. Turns out the shop where i bought the battery from (another shop) sold me a bad battery, saved me a bunch of dollars, i thought somthign was seriosuly wrong with it. Thanks for all your guys time and help with the issue and tryign to help me out i appriciate it alot.