patspiercing Posted August 14, 2018 Share Posted August 14, 2018 I have just had a problem with my wifes Virago smelling of eggs after a rideout. It turned out that it was the rectifier regulator overcharging the battery. It boiled the battery dry before we found the problem. The rectifier was giving 16.9 volts. Changed it and all seemed ok . We went for a ride out and found that the fault had also blown the headlight, side light, both tail light and the right side indicator bulbs. All changed and back on track now, or so we thought. After changing the regulator/rectifier and checking that it was charging at 14.2v I refilled the battery with distilled water and was quite suprised that it held a charge. However, after about 300km of riding it has boiled the battery dry again. Again I refilled it with distilled water and it holds a charge, although only at 12.5v. I have rechecked the charging system and I am still getting 14.2v at about 5,000 revs. The only thing I can think of is that as the boiling point of water is lower than the boiling point of electrolyte the battery is boiling due to lack of acid. I have now ordered a new battery and hopefully this will cure the problem. Link to comment Share on other sites More sharing options...
Moderator Cynic Posted August 19, 2018 Moderator Share Posted August 19, 2018 Topping a battery up is one thing filling it from dry is another. The battery is as good as dead and may blow your new reg/rec unit. Link to comment Share on other sites More sharing options...
patspiercing Posted August 19, 2018 Author Share Posted August 19, 2018 Have now changed the battery and all seems fine. Link to comment Share on other sites More sharing options...
patspiercing Posted August 23, 2018 Author Share Posted August 23, 2018 Just checked the charging rate and it is showing over 18 Volts and is boiling up the new battery. I can only assume that the new rectifier/regulator has gone faulty again. Anybody with any thoughts. Link to comment Share on other sites More sharing options...
NE0 Posted August 23, 2018 Share Posted August 23, 2018 (edited) the new rectifier/regulator..... Pattern part ? or Genuine? Edited August 23, 2018 by NE0 Link to comment Share on other sites More sharing options...
Moderator drewpy Posted August 23, 2018 Moderator Share Posted August 23, 2018 checked earth? does the RR get hot? (it should do) I bough a mosfet and it heated up the stator wires, luckily I found it before any damage, put in a SHE650 and all was fine Link to comment Share on other sites More sharing options...
patspiercing Posted August 23, 2018 Author Share Posted August 23, 2018 Pattern part. It does get hot. I have checked the earth mounting points for the R/R and they are all clean. i have checked the connectors and all seems clean and good. I have checked the alternator and all readings are within limits. I can only think that the R/R has died. I have ordered another one and hopefully will have more luck with this one Link to comment Share on other sites More sharing options...
Moderator Cynic Posted August 23, 2018 Moderator Share Posted August 23, 2018 Do yourself a favour and if you do have to top this battery up by any real amount, use battery acid. Your battery could have goosed the new RR. Link to comment Share on other sites More sharing options...
patspiercing Posted August 24, 2018 Author Share Posted August 24, 2018 It was a new battery that I fitted, filled with battery acid, so that should not be the problem. But thanks for your thoughts. Link to comment Share on other sites More sharing options...
Moderator Cynic Posted August 25, 2018 Moderator Share Posted August 25, 2018 Don't fall for assumption. When you have problems you should always check when things change. Especially easy checks like batteries. Check the standing voltage (should be 13 and a bit in a good battery). The battery voltage controls the current through the rr. It's used a bit like a reference figure. So a low battery will have the rr working its nuts off trying to bring the V down. Reduce the voltage you increase the work. ie current. Link to comment Share on other sites More sharing options...
patspiercing Posted August 25, 2018 Author Share Posted August 25, 2018 Have checked the battery voltage and it is 13.2 Volts. I have spoken to a electronics engineer and he has said that with the readings that I have he would say that the zenor diode in the R/R has short circuited and I am then delivering the full alernator output to the battery. I am just going to have to wait for the new R/R to arrive and see how we go. 1 Link to comment Share on other sites More sharing options...
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