Battery Charging

[Jazzscot]

I have tested my R+R using a multimeter between the terminals and it was showing 17 volts which means is is fecked. I did the R1 R+R mod and voltage was reading 13.8 (all good) went for a run after a refuel stop the fecker wouldnt turn over (flat battery) garage was at the top of a big hill so managed to bump start in 3rd gear. Got home battery charged fine from battry charger. Went out again for a run to test and when I got home battry was flat again. Put my old R+R back on and bike runs fine at the moment done around 300 miles with no probs.

My question is do you think the battery has gained a memory at being charged at the higher voltage??? I will get a new battery next week but I was after your thoughts.


Jazz

[benny hedges]

more likely you got a wire wrong tbh unless you bought a duff yammy rr - not unheard of as a m8s virago was frying batteries at 18v, same rr

[Jazzscot]

Nope wiring was all correct and was showing the correct voltages accross the battery when connected etc. Tested the outputes as per Tony.mon. All voltages were within spec. As I said before battery wants replacing but just wondered if the battery is causing the fault.

Fair enough, all you can do is start at the charging circuit and see what outputs you have all the way through, connecting things up one at a time.
So:
Disconnect reg/reg, turn off all lights, connect battery, turn on ignition and see if there's a current drain on the battery.
if you watch the voltage dropping with a meter across the terminals set to voltage (up to 20 will do) then something's eating your current, best find out what. Do this by unplugging things until it stop, then chase the connectors out until you isolate the fault.

If there's no appreciable current drop then try to start the engine.
Assuming that's ok, move on to the reg/rec:

At the reg/rec output connector under the tail plastics, RH side, find which three wires come from the alternator windings. Connect the voltmeter (set to up to at least 100 volts), red to each output lead in turn, black to ground, frame or batt neg.
These three should output a voltage between about ??14 and ??40 volts, increasing as you rev the engine. (I am not sure exactly what voltages you get, but anywhere like this is fine).

Now find the lead that goes form the reg/rec connector to the battery, this is the output from the alternator once it's been rectified and regulated, so shouldn't be more than 14.5-15 volts, really.
Disconnect it from the battery end, because you don't want to be shooting excess voltage up a new battery, and put the red meter lead (range up to 20 volts) on the r/r output and the black one on the frame or batt negative.
With the alternator connected to the reg/rec you should now get a voltage that varies between 13 and 15 volts-ish. A volt or two either way is fine.

If this all checks out then you have a short elsewhere, can't be more specific than that.
But from what you've said the battery is draining quickly enough that it doesn't seem to be a normal flat/tired battery, short across alternator windings or reg/rec feels more likely.



I'm no electrician, and if someone on here has more detailed advice, please chip in.

[Pete.L]

I think you'll find your problems go away when you replace the battery. First signs of a battery going off is, not holding a charge, or slow to turn over at start up.
If the reg had gone to 17v this is enough to damage the battery and finish it off prematurely. (If you tell me it's seven years old now, I might have to kill you, it is a consumable you know ).
Only one question, if I'm reading your post correctly have you put on a new reg or the old faulty one and if so,Why?

Oh, and the bigger 14 amp/hour battery is a good move also go for the more expensive one, you'll spend less time bump starting it on cold mornings
Pete.l

[Jazzscot]

put old R+R back on till I get new Battery this week, this was because new R+R was not able to keep a charge in it.

Jazz

[tony.mon]

If new r/r is not able to keep a charge in the battery and the old one is, assuming you're right about the connections and installation being correct with the new one then you're probably keeping your old, knackered battery topped up and then some by putting excess volts and current through it.
If this is the case then it'll take a good charge but not hold it for very long. If you're using the bike for daily commutes it might be able to keep enough charge overnight, but might drop to less than "turning the engine over" voltage of about 12v if you leave it for two or more days.

Be careful, because this will overheat the battery and could cause the casing to crack and leak acid over your bike (and maybe leg!).

Most times the battery is f*cked if the r/r has gone and needs to be replaced at the same time.

But as Pete says, these are consumables, you might as well get used to replacing one every now and then.
Some seem to last years, others just a couple of years, and in my experience it isn't related to cost, i.e. a more expensive battery doesn't always last longer.

But it's difficult to be exact with comparisons; your pattern of riding changes, battery technology is gradually improving, and my memory isn't what it .......what was I saying again?

I suppose if a cheap battery lasts two years but is half the price of one that lasts four years, there's not much in it.