850 T5 reg/rectifier

No, it happens anyway; when you pass an electric current through water, which the electrolyte is four-fifths, you split it into oxygen and hydrogen, ergo, water gradually disappears. I agree though it shouldn’t disappear quickly. But, that’s why maintenance blurbs always tell you to check the levels in all the cells. Personal note: I find those at the negative end of the battery tends to go down more.

PS: if you got a battery on a charger you can often hear it bubbling when it’s “done”, that’s the oxygen / hydrogen bubbles coming off, which happens more so when the actual charging chemistry is ending. I.e., can’t get much more in.

Hence the other warning in the maintenance blurbs, keep naked flames away! “Explosive mixture”

Mike H2012-06-23 12:49:08

Anyway this wasn’t really why I came here ~ the Electrex web site has ‘moved’, and now they’ve put the actual RR45 instructions PDF up on the page:

http://www.electrexworld.co.uk/acatalog/RR45.pdf

Very interesting, take note of the part about the orange wire, which explains why some people have been having trouble (e.g. BMW forums I was looking at earlier) either getting it to work at all and/or the charge warning light won’t light up ~ it has to be a 2W bulb (not your usual 1.2W).

Also seems to explain Ex_smokingbiker’s problem of too high Volts 'cause there was a Voltage drop across the ign switch and wiring to where this orange wire was connected. (To ign coils positive, he said.) I assume it was the orange…

Studying the diagram, I can now get a handle on how this orange wire must be disconnected (ign off) to prevent the thing draining battery current while the ign is off, and conversely, reg won’t start up and work until this wire is getting correct battery current.

yep that was my problem the volt drop on ignition and kill switch the orange wire hence the relay direct to battery curred it and if you connect the orange direct yes it flattens the battery