My Battery discharges to an unusable state in a few days unless connected to a battery charger while not in use.  I attached a current meter in series with the battery and discovered that with the ignition switch off, and the Run/Stop switch on, the meter is showing ~40mA current flow.  I can't test with the Run/Stop switch off, because a relay starts cycling at about a 1sec rate.  I am uneasy about leaving the switch in this state long enough to find out which relay, but I suspect that it is the ECU relay.  Does anyone know what is normal current drain with the ignition switch off?

There should be no current draw.

Which ECU do you have.
Most late bikes have the instrument panel powered. Take a measurement with the ECU disconnected.

Either way 40ma is going to be a discharge of 1AH per day. Your battery should be around 20Ah so if it is draining that quickly I suspect you battery has problems.

I have a My16M in a '97 Sporti.  With the ECU disconnected, there is negligible current drain (it may be just the zero setting of the current meter).  I disconnected the ECU because pulling the ECU fuse was the first indicator that the current drain was there.  By the way, I am using pins 10 and 15 as the O2 sensor inputs ( I have two O2 sensors installed).  I disconnected those external wires and saw no change in current with the ECU still connected.

Is it the MkIV or the MkIII

Do you get the fuel pump cycle when you turn the key on?

There are two places where the 12V can enter the ECU.

First there is pin 26. This is the  keyed +12V and should therefore by at 0V when the key is off.
This input switches a transistor that pulls in the ECU  relay.

The output of the transistor is pin 4. This should be at 12V. It is pulled to 0v to energise the relay.

The main feed is pin 35. This should be at 0V when the relay is not energised.

Yes, the fuel pump cycles when I turn the key on.  I will check pins 26 and 35 and report the results.

Well, no more testing today.  When I turn the ignition switch on, the fuel pump murmurs slightly, and the voltage at pins 26 and 35 drops to ~6.5 volts.  Looks like I need a new battery in order to check things out properly.  :(

I couldn't resist... I plugged in my Battery Tender and checked that the voltage was 14.4V at the battery.  The voltage at pin 4 is 10V with the ignition switch off.  Pins 26 and 35 are 0V.

That all sounds normal.

The fact that your battery is already at 14.4 volts is a concern. What current does you charger pump.
A healthy battery that was discharged should slowly rise in voltage at reasonable currents.

10V at pin 4 sounds interesting. I think relay is about 150 ohm so the 4V across it could explain the current.
The transistor (leftmost FET near L2 on MkIV)shouldn't be drawing any significant current unless it is failing.

If it fails completely then the ECU will be permanently energised ( no fuel prime with key on symptom )
If you did the kit you might want to replace that FET.

Otherwise you should send the ECU back to me for repair.  Probably best to wait till your riding season finishes.

I have a Deltran Battery Tender (p/n 021-0128) which is supposed to be correct for AGM type batteries.  It pumps 1.25A Max.  I have a YUASA YTX15L-BS battery in the bike at this time.  It was supposedly fully charged when I started the testing, so I suspect that since it dropped immediately to 6 volts at the ECU, I am going to have to replace the battery anyway.  Although I purchased the ECU, not the kit, from you, I feel competent to replace the FET.  I defintely have a MKIV ECU.  Which FET are you referring to? There are 3 devices to the left of L2.  Do you mean Q6, Q7, or Q3?  I don't know where to get an equivalent FET here in Oregon, can you send me a cross-reference or the electrical specs so I can search here?

Can you send me an email and I'll send you the kit instructions.

A 1A charger is basically going to take 10-20 hours to fully charge. The voltage will gradually increase over that time. The fact that yours has come up so fast really puts suspicion on the battery.

I put lithium batteries in 2 of my 3 bikes including the My Sport 1100. Its never turned over so quickly.

I sent you a PM with my email address.  I have been looking at the Shorai Lithium batteries.  186USD is a bit steep compared to 75USD for the YUASA, but it sounds like it's worth it, and Shorai says the Deltran charger is compatible with their batteries.
Thanks again for all your help.

Lead acid batteries are really cheap over there.
Name brand batteries here are similar to the Lithium price.

May have nothing to do with the issue but I lost the Odyssey battery charge a couple of weeks ago and it took me two cycles (of recharge) to pin down that I had knocked the LC1 switch to calibration inadvertently. As usual just about to rip everything apart before I clocked the red led and said to myself "what's that all about?" Doh!
:-/

Good thought, but my Calibration switch box is mounted in the under-seat area right next to the battery, and the lights only came on when the ignition switch was turned on.  This morning, I turned the switch on to check, and my battery immediately dropped to 6V.  Definitely new battery time. :(

I have ordered a new FET, bought a .1uF cap, and ordered a new battery.  While waiting for these things to arrive, I decided to check my wiring, just in case.  My two LC-1 O2 sensors are being powered from pin 87(NO) of the ECU relay, which also powers the ECU.  Is that the correct way to do it, or should I add a separate relay to the relay bank?

Yes that is ok. Mine are powered from the fuel pump relay.

I like your idea better.  I will re-do the wiring while I wait for the parts.  Thanks.

I got my new Shorai battery Saturday, and installed it Sunday.  The Lithium battery is less than half the weight, and about 2/3 the size of my old battery.  I removed the O2 sensor power wires from the ECU Relay and installed them on the Fuel Pump Relay.  The first thing I noticed when I turned on the ignition switch is that the O2 sensors are only heated for about 2 seconds, while the Fuel Pump is running.  That is not long enough to bring the O2 sensors up to temperature.  The LC-1 Manual has me confused on the heating issue.  On one hand, they say the LC-1s must be connected and operating when the engine is running.  On the other hand, they say it is NOT a good idea to switch it on before the engine is started.  What experience do other LC-1 users have, and how did they connect the power? :-[
BTW, I pulled the Headlamp relay while I am doing the testing and adjusting to save the new battery.

The LC1 requires about 30 seconds to be useful.
Your way you only had a 5 second jump.

MyECU has a few delays in going into closed loop. It will wait for the oil temp to rise a certain amount.
This can be shortened by taking the engine over 3000RPM. This was for some in cold climates and short trips.

With my Breva 750, which spins too easily, I sometimes find I've started going closed loop before the sensor is working properly.

So, since I am now powered off of the fuel pump relay instead of the ECU relay, the sensors will get a 2-5 sec heat, and then resume heating while the engine is cranking and running, but since the ECU won't go closed loop until the oil temp is up, everything should be OK, right?

Yes, and keep the revs under 3000.

OK, got it.  Thanks again for your help and advice. ;D

I had this problem with my M16 Kit, T6 is a transistor driving the ecu relay, and as  Field effect transistor  device is easy to damage by electrostatic discharges, not a issue in tropical weather with 75 and up humidity porcentage.
Any way it was swaped by a litle reed relay,(recycled). End of the problem. Think a relay is not fancy but more reliable. My opinion ;)

A lot of reed relays are sensitive to vibration, but I will keep that in mind.  I have a collection of small reed relays left over from early days in the instrumentation field.  Right now, everything is fine, so I am reluctant to "crack the shell" again.