...<snip>
The topic I wanted to present is my continuing issue, findings, and solutions related to battery discharge. This has happened three times in two years - always at the most inopportune time. The last being while solo camping at the Manicouagan Reservoir in Québec on my way to Labrador.
After a 14 hour day of riding at road speed with the alternator charging over 14 volts, the battery could not even muster a pilot light on the dash after 12 hours at rest. I was able to jump start the bike by using my Antigravity MicroStart kit (highly recommended!) but I decided to scrub the trip and come home, not wanting to proceed into a desolate area while relying on my back-up to start the bike.
This issue hasn't happened frequently, but the problem is that when it DOES happen, it is torture on the battery, and after a couple of them, the battery is toast. It is kind of like the guy who is generally well-behaved but occasionally he tosses a hand grenade into a crowd. In researching this problem, I came up with a list of observations…
1) Not every bike has the problem. In fact, most do not.
2) Some problem bikes had added circuits and others were factory stock.
3) The problem is intermittent, not sustained.
4) The “event” proceeds without sight or sound (no lights, fans, pumps, etc.)
5) The problem drain is therefore unswitched, otherwise lights and such would be energized.
6) The “event” drains sufficient current to kill the battery in only a day or two.
One is not likely to diagnose an event that happens every six to twelve months with measuring equipment. When measured, it will be fine. That is why cardiac and apnea patients often have to wear recorders. The symptoms don’t show in the doctor’s office. I have recorders I can connect for parasitic drain, voltage, etc., but with the long interval, even recorders are unlikely to catch it happening. Therefore, it can only be analyzed from a theoretical standpoint with some kind of measure used to mitigate the damage caused by the event.
My analysis of the circuit schematic points to the only sensible source of intermittent drain to be the rectifier/regulator. It is unswitched and has power and ground available to it at all times. Any drain from the R/R would proceed without lights or sounds. In fact, in the diagnosis of parasitic drain, the Honda repair manual suggests testing drain current with and without the R/R attached to confirm whether it is the problem. So, it CAN do it, but we are back to diagnosing a very intermittent problem so we won’t likely catch it in the act.
The alternator on the Honda is of the permanent magnet design. Which means that unlike a wound rotor alternator that controls its output by field controls, the Honda alternator puts out full power at all times and relies on the regulator to control voltage by returning the unneeded power to ground. The Honda 31600-KVZ-631 rectifier/regulator is a MOSFET regulator rather than the simpler (and less efficient) SCR shunt design. Either way, it contains within its finned aluminum case an intentional ground path for current and a ready supply of battery juice to consume. The R/R costs about $200. I could replace it on the strength of my theory and wait a year or two to see if it consumes another battery, but if I am wrong I have wasted the $200 for the R/R and toasted another $100 battery. What I determined that I needed was some way to prevent the damage and inconvenience caused by the event.
I was aware of a number of “battery protectors” for automotive and marine use that disconnect the battery from the circuit once it discharges to a set value. This seemed to be the kind of device I was looking for. I have one of these on my Silverado because of all my ham radio gear.
In looking at a number of the devices like this, I concluded the following…
1) I don’t need the size and weight of a device that can handle 200 amps continuous and 1000 amps of starting surge. I only need 50 amps sustained and 250 amps of starting surge (with safety margin included).
2) Most of them trigger at voltages that I consider too low (10.0 to 11.8 volts). The NC battery is 90% discharged at 11.8 volts. I wanted a setpoint of 12.2 volts which relates to a 50% discharge.
3) A number of them presented what I considered too much parasitic loss of their own in order to operate the device. I made myself a somewhat arbitrary limit of 5 ma to shoot for.
After much digging, I found EXACTLY what I was looking for. It is a Model T5 Sport Battery Protector offered by STRS Energy.
It is very compact; programmable for both trigger time and voltage; and sufficiently rated at 80A / 250A. The stock unit comes preset for an 11.8 volt setpoint. I found that by phoning the order, I could get them to program it for 12.2 volts. They counseled me that they considered 12.2 volts to be too high, but they were willing to do it. If I am wrong, I can get it re-programmed. I did not want to invest in the $400 programming unit.
The contact information for STRS Energy is:
STRS Energy Inc.
8-04 Arnot Place
Fairlawn, NJ 07410
P- 201-968-7042
F- 201-548-5252
E-mail: [email protected]
T5
As usual, I made the installation more involved than it needed to be. I decided to locate the device in the mysterious covered compartment at the bottom of the Frunk. I have no idea what this neat little enclosed space is intended for, but it is perfectly sized and placed for the battery protector. The battery protector produces no heat, so the confined space is not a problem. I cut in a couple of bushings for wiring ingress and egress…
The battery cables have big bent terminals on them. I did not want big taped up bolted connections to them and I did not want to cut the terminals off in case I wanted to back out of the modification. So, I removed the stock cable and replaced it with custom cables made from double runs of silicone sheathed 10 gauge wire.
The battery wire is removed from the supply side of the starter relay.
Removing the battery side required removal of the fuse box.
While the fuse box was removed, I inserted a fusible tap to the red/white wire to the clock and turn signals. The T5 has a switch that allows it to be used as a battery disconnect switch as well as a protector. With this tap, I can wire the bike’s computer straight to the battery so that the instruments and clock do not reset when the device is operated. Obviously, protection is reduced anytime a load is moved from the protected to the unprotected side of the switch, but in this case I thought that the convenience might be more important than the protection. I really do not believe that the bike’s computer with switch “off” can consume the amount of current that is causing this problem. Either way, if I keep the fuse in it’s original position, it will be switched off with the T5. If I move the fuse to the tap, the computer will remain lit. Easy choice, but best to do while the fuse box is in your hand and the magic wire is accessible. No downside.
Here is the installation complete in the bottom of the mystery compartment. I placed the operating switch out the bottom left side of the compartment, which is easily accessible by reaching up under the left side cover.
So now I will install a new battery and see how it goes. If the “event” happens, I will know because the device will have operated. If it happens often, I will install the spare R/R that I purchased. Actually I am not sure that I am even going to keep the motorcycle. I built it for long distance expedition travel on unimproved roads, and I don’t think I am going to do any more of that. But even if I sell the bike, I do not want to pass off a known problem to someone else. This was built as a “best of everything” motorcycle and leave or stay, I don’t want it to have a big wart on it. If I am going to limit myself to regional travel on improved roads, I would rather ride one of my BMW’s. Especially since I finished the rebuild of the R1150R that I took to Prudhoe Bay and Inuvik. I also recently purchased a very pristine R100RS from a museum that needs badly to accumulate some miles after living it’s life to-date sitting on a polished oak floor.
My best to my friends. I will be at the North Carolina Horizons Unlimited riders meeting until about Friday afternoon. The event is put on by a good friend of mine whom I haven’t seen in a while. If it works out going forward that the NC doesn’t get much use, it will be passed along to someone who will use it for the purposes for which it was built.
Lee
The topic I wanted to present is my continuing issue, findings, and solutions related to battery discharge. This has happened three times in two years - always at the most inopportune time. The last being while solo camping at the Manicouagan Reservoir in Québec on my way to Labrador.
After a 14 hour day of riding at road speed with the alternator charging over 14 volts, the battery could not even muster a pilot light on the dash after 12 hours at rest. I was able to jump start the bike by using my Antigravity MicroStart kit (highly recommended!) but I decided to scrub the trip and come home, not wanting to proceed into a desolate area while relying on my back-up to start the bike.
This issue hasn't happened frequently, but the problem is that when it DOES happen, it is torture on the battery, and after a couple of them, the battery is toast. It is kind of like the guy who is generally well-behaved but occasionally he tosses a hand grenade into a crowd. In researching this problem, I came up with a list of observations…
1) Not every bike has the problem. In fact, most do not.
2) Some problem bikes had added circuits and others were factory stock.
3) The problem is intermittent, not sustained.
4) The “event” proceeds without sight or sound (no lights, fans, pumps, etc.)
5) The problem drain is therefore unswitched, otherwise lights and such would be energized.
6) The “event” drains sufficient current to kill the battery in only a day or two.
One is not likely to diagnose an event that happens every six to twelve months with measuring equipment. When measured, it will be fine. That is why cardiac and apnea patients often have to wear recorders. The symptoms don’t show in the doctor’s office. I have recorders I can connect for parasitic drain, voltage, etc., but with the long interval, even recorders are unlikely to catch it happening. Therefore, it can only be analyzed from a theoretical standpoint with some kind of measure used to mitigate the damage caused by the event.
My analysis of the circuit schematic points to the only sensible source of intermittent drain to be the rectifier/regulator. It is unswitched and has power and ground available to it at all times. Any drain from the R/R would proceed without lights or sounds. In fact, in the diagnosis of parasitic drain, the Honda repair manual suggests testing drain current with and without the R/R attached to confirm whether it is the problem. So, it CAN do it, but we are back to diagnosing a very intermittent problem so we won’t likely catch it in the act.
The alternator on the Honda is of the permanent magnet design. Which means that unlike a wound rotor alternator that controls its output by field controls, the Honda alternator puts out full power at all times and relies on the regulator to control voltage by returning the unneeded power to ground. The Honda 31600-KVZ-631 rectifier/regulator is a MOSFET regulator rather than the simpler (and less efficient) SCR shunt design. Either way, it contains within its finned aluminum case an intentional ground path for current and a ready supply of battery juice to consume. The R/R costs about $200. I could replace it on the strength of my theory and wait a year or two to see if it consumes another battery, but if I am wrong I have wasted the $200 for the R/R and toasted another $100 battery. What I determined that I needed was some way to prevent the damage and inconvenience caused by the event.
I was aware of a number of “battery protectors” for automotive and marine use that disconnect the battery from the circuit once it discharges to a set value. This seemed to be the kind of device I was looking for. I have one of these on my Silverado because of all my ham radio gear.
In looking at a number of the devices like this, I concluded the following…
1) I don’t need the size and weight of a device that can handle 200 amps continuous and 1000 amps of starting surge. I only need 50 amps sustained and 250 amps of starting surge (with safety margin included).
2) Most of them trigger at voltages that I consider too low (10.0 to 11.8 volts). The NC battery is 90% discharged at 11.8 volts. I wanted a setpoint of 12.2 volts which relates to a 50% discharge.
3) A number of them presented what I considered too much parasitic loss of their own in order to operate the device. I made myself a somewhat arbitrary limit of 5 ma to shoot for.
After much digging, I found EXACTLY what I was looking for. It is a Model T5 Sport Battery Protector offered by STRS Energy.
It is very compact; programmable for both trigger time and voltage; and sufficiently rated at 80A / 250A. The stock unit comes preset for an 11.8 volt setpoint. I found that by phoning the order, I could get them to program it for 12.2 volts. They counseled me that they considered 12.2 volts to be too high, but they were willing to do it. If I am wrong, I can get it re-programmed. I did not want to invest in the $400 programming unit.
The contact information for STRS Energy is:
STRS Energy Inc.
8-04 Arnot Place
Fairlawn, NJ 07410
P- 201-968-7042
F- 201-548-5252
E-mail: [email protected]
T5
As usual, I made the installation more involved than it needed to be. I decided to locate the device in the mysterious covered compartment at the bottom of the Frunk. I have no idea what this neat little enclosed space is intended for, but it is perfectly sized and placed for the battery protector. The battery protector produces no heat, so the confined space is not a problem. I cut in a couple of bushings for wiring ingress and egress…
The battery cables have big bent terminals on them. I did not want big taped up bolted connections to them and I did not want to cut the terminals off in case I wanted to back out of the modification. So, I removed the stock cable and replaced it with custom cables made from double runs of silicone sheathed 10 gauge wire.
The battery wire is removed from the supply side of the starter relay.
Removing the battery side required removal of the fuse box.
While the fuse box was removed, I inserted a fusible tap to the red/white wire to the clock and turn signals. The T5 has a switch that allows it to be used as a battery disconnect switch as well as a protector. With this tap, I can wire the bike’s computer straight to the battery so that the instruments and clock do not reset when the device is operated. Obviously, protection is reduced anytime a load is moved from the protected to the unprotected side of the switch, but in this case I thought that the convenience might be more important than the protection. I really do not believe that the bike’s computer with switch “off” can consume the amount of current that is causing this problem. Either way, if I keep the fuse in it’s original position, it will be switched off with the T5. If I move the fuse to the tap, the computer will remain lit. Easy choice, but best to do while the fuse box is in your hand and the magic wire is accessible. No downside.
Here is the installation complete in the bottom of the mystery compartment. I placed the operating switch out the bottom left side of the compartment, which is easily accessible by reaching up under the left side cover.
So now I will install a new battery and see how it goes. If the “event” happens, I will know because the device will have operated. If it happens often, I will install the spare R/R that I purchased. Actually I am not sure that I am even going to keep the motorcycle. I built it for long distance expedition travel on unimproved roads, and I don’t think I am going to do any more of that. But even if I sell the bike, I do not want to pass off a known problem to someone else. This was built as a “best of everything” motorcycle and leave or stay, I don’t want it to have a big wart on it. If I am going to limit myself to regional travel on improved roads, I would rather ride one of my BMW’s. Especially since I finished the rebuild of the R1150R that I took to Prudhoe Bay and Inuvik. I also recently purchased a very pristine R100RS from a museum that needs badly to accumulate some miles after living it’s life to-date sitting on a polished oak floor.
My best to my friends. I will be at the North Carolina Horizons Unlimited riders meeting until about Friday afternoon. The event is put on by a good friend of mine whom I haven’t seen in a while. If it works out going forward that the NC doesn’t get much use, it will be passed along to someone who will use it for the purposes for which it was built.
Lee
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