1954 88 batteries draining

Hello Peteralan, if you have an alternator fitted,have you by any chance replaced the PRS8 ignition/light switch?

It is possible when you have two batteries connected in parallel for one to have a slightly higher voltage than the other and a small current to flow between them slowly draining them. Not a problem of course when they are connected in series for 12 volts. That is one reason I prefer to have a single 5Ah battery on my 6 volt machines.

If you suspect a wiring fault, substitute a normal 6V battery and see if it discharges. If yes, it's wiring, if no, it's the batteries connected in parallel.

Previously peteralan_hathaway wrote:

just installed 2 no 6V 4.5AH batteries connected in parallel into dummy battery box.

I have connected via positive earth,not left any lights on etc but the batteries are draining.Anybody got any idea what my problem might be?

If you have a DVM just put it on the 10A scale in series with the battery. Turn the lights on and see a value on the meter so you know it is connected correctly. Now, with the lights / ignition off, change down the range to mA. You should see zero. If you see anything then it is time to start disconnecting things until it goes to zero.

What bike is it ? What charging system ? Alternator / Dynamo. What regulator / rectifier setup ?

Regards

Tony