Charging system problem ... need help please!

I just bought my first motorcycle a week ago and I'm already having trouble. I didn't know a whole lot about bikes, but learned a lot this past week haha

I just bought a 2001 SV650 a week ago. The guy I bought it from told me that the battery had a bad cell and wouldn't hold the charge. I took the battery to a battery store and they confirmed it had a bad cell, so I bought a new one. Bike ran fine for about two days, then the battery was dead again. I did some research online and used this checklist to troubleshoot: http://www.electrosport.com/media/pd...ng-diagram.pdf

According to the checklist the R/R was shot. I could tell the R/R had been replaced, because the wire coloring was wrong and it wasn't as dirty as the rest of the bike. Again I did some research and figured I should do D'Ecosse's mod, so I picked up a used R/R from a 2006 CBR 600, did the mod and everything.

When the bike idles the multimeter shows about 14.7V at the battery. When I rev the engine to 5000RPM the voltage drops to 10V or under. I don't know what the problem is. I went through the checklist again and the stator checked out fine and this R/R is supposedly also shot. But I am wondering, is this R/R really shot as well or is there another problem? Should I check the fuse?

Any help is greatly appreciated, as I don't know what else to do and I would hate to spent another $130 on a new R/R and then still have the same problem.

[squirrel_hunter]

Its not going to be the or a fuse. Your options in no particular order are: wiring fault, reg/ rec, battery, alternator.

Lets assume your battery, bought new is still good. So that gives us the reg/ rec as the next possibility, your previous one was faulty, but how do you know the replacement second hand one wasn't? You also modified it, no offense intended but are you sure the modification was successful? Which leads us to wiring, a visual check might highlight any issue such as a damaged wire or corroded contact, signs such as melted plastic at connectors could point to a problem. Trace the wires from the alternator to the reg/ rec and back to the battery, plus the main earth is worth a look at while you're poking around. Finally you say you checked alternator, what were the voltage results from that?

There is lots on the subject on this forum, I find this thread very helpful when dealing with charging issues as it goes into great detail.

Thanks for your quick reply. I just read through the entire thread and got some good ideas what else to check for. I'll work on it more tomorrow and post more details on what I did and what the results were.

if you know very little about reg/rec,then stick to the original suzuki fittment that is known to work,as to batteries some dont like going flat and that alone can bugger them up,and personally would never us a secondhand reg/rec as they have a limited life span and you dont know what you are buying,and honda reg/rec are no better then suzuki ones and run hot and go wrong,and on a good day i would say a honda or suzuki reg/rec would last between 20 to 30k,my vfr has had about 3 reg rec in 36k looking at the service history with the bike the original a second hand one and a new david silver one i fitted at about 34k

I started the test checklist today again and I don't know what happened over night, but when I took the voltage of the battery with the engine running at idle and at 5000rpm it stayed constant at about 14.7 volts. I rode the bike around for a while and took the voltage of the battery with the bike off and it definitely charged the battery. My conclusion, either I did something wrong when measuring yesterday or I have an exposed wire somewhere that causes the system to go gaga. Thanks for all the help though!

[embee]

It's been discussed numerous times in numerous forums, but a very short summary is that it isn't just any old Honda reg/rec, but it's the MOSFET ones which are an improved item.

These use a different semiconductor (MOSFET) to do the business, they generally have less internal heat genration due to the technology and deliver a more stable output. The technical details are available elsewhere in great depth. They still work on a shunt principle though.

They are generally rather bigger physically than the std SV item and connections are different so some mods are required to fit one. They are often referred to as a "Shindengen" type, see Shindengen site .
I think a lot of folk have had useful help/parts from Eastern Beaver

They come in various forms, recognisable by an "FH" reference (FH008, FH010 etc) but with different physical appearance. As far as I know they generally have a double socket arrangement (3 phase versions), I've fitted 2 to a couple of my bikes, one came from a Honda ATV and one from a Kawasaki ZX10. I didn't get the correct plugs, though that would make a much more professional installation, I simply got the blade connectors out of the stock plug and fitted separate plastic blade covers.

The 3 alternator wires can go on any of the 3 inputs, just make sure you get the pos and neg output wires on the correct pins. AFAIK the pos/neg is always in the same arrangement as shown in the Eastern Beaver site pics (pos is the inboard pin), but always double check.

Originally Posted by embee

It's been discussed numerous times in numerous forums, but a very short summary is that it isn't just any old Honda reg/rec, but it's the MOSFET ones which are an improved item.

These use a different semiconductor (MOSFET) to do the business, they generally have less internal heat genration due to the technology and deliver a more stable output. The technical details are available elsewhere in great depth. They still work on a shunt principle though.

They are generally rather bigger physically than the std SV item and connections are different so some mods are required to fit one. They are often referred to as a "Shindengen" type, see Shindengen site .
I think a lot of folk have had useful help/parts from Eastern Beaver

They come in various forms, recognisable by an "FH" reference (FH008, FH010 etc) but with different physical appearance. As far as I know they generally have a double socket arrangement (3 phase versions), I've fitted 2 to a couple of my bikes, one came from a Honda ATV and one from a Kawasaki ZX10. I didn't get the correct plugs, though that would make a much more professional installation, I simply got the blade connectors out of the stock plug and fitted separate plastic blade covers.

The 3 alternator wires can go on any of the 3 inputs, just make sure you get the pos and neg output wires on the correct pins. AFAIK the pos/neg is always in the same arrangement as shown in the Eastern Beaver site pics (pos is the inboard pin), but always double check.

the (moset)"Shindengen" type may well be better then the suzuki fitment, but they are far from being reliable on most honda's they are fitted to,the latest one has fins front and rear,they still get hot when fitted to a honda and i wouldnt expect one to last more then 20k.
going by what is said on here about reg/rec on sv's then i would say the only suzuki range that doesn't suffer from reg/rec problems are the older bandits that had the reg/rec as part of the alternator,dont suppose it looks any thing like the sv alternator because that could solve the problem forever