Does anybody know if there is there a small 12V battery hooked up to the DC2DC converter on the Zero bikes?
I am seeing behavior that I can't quite explain...
I have Oxford heated grips and the heated seat from Zero on my 2014 S. The Oxford heaterz will cut OFF if voltage drops below 11.5V. I have seen that sometimes they are cutting out in the middle of my ride?!?! Anyone familiar with these grips will know that they also have a voltage sense feature that looks for noise on the 12V to try to determine when the bike has been turned OFF. I was concerned that the 12V DC2DC on an electric bike wouldn't have enough noise on it compared to a rectifier on an ICE bike so I turned that feature OFF (voltage should be pretty smooth in general compared to ICE but especially at stop signs and stop lights or any time the bike isn't moving). The grips are connected to the SAE accessory connector on the bike that turns OFF when the bike is turned OFF. The seat is connected to the other switched power connector...I think its sumitomo? I don't have any Y adaptors.
So to trouble shoot I hooked a meter to see if the voltage is dropping below 11.5V. The battery on the bike is fully charged and has been plugged in over night. The first time I hook up I read 11.9V after turning ON both the seat and the heated grips (100%). Of course the voltage is higher when stuff is turned OFF or if I set the grips to a lower %...I don't remember the exact number but its over 12V. So, while I am doing this the bike is still plugged in even though the battery is full and as I am checking the voltage I see that it is slowly going up. 12.1V, 12.2V....12.6V....so I decide to do a test and I walk away from the bike with everything ON. When I come back about an hour later it looks like things have settled around 12.65V. Turn stuff OFF and again it goes up to over 13.5V. The whole time I am away from the bike I am recording on the meter and not only have the grips stayed ON the whole time but the voltage never dropped below 11.5V.
Time to do another test. I leave the tank OFF and the meter connected. Zip tie down the meter, set the record button on the meter, unplug the bike and head out for a ride. I ride for over 50 miles and the heat stays on the whole time. Previously the grips would cut out on ever ride after less than 5 miles....not even enough time for them to get fully cooked up. Get back to base and check the meter and of course the voltage has never dipped below 11.5V during my ride but it did slowly fall the whole ride. It started at 12.65V and I was down to 12V when I got back.
I plug back in and I watch the voltage slowly rise again. I leave it until the voltage settles again at 12.65V. I turn OFF the heated accessories and leave the bike ON while plugged in for a little bit longer. I disconnect everything and put the bike back together. For almost two weeks everything works great and the heat stays on for my entire commute. Until yesterday when it starts cutting out again. So last night I turn on the bike while it's plugged in and leave it for an hour or so. Today, no issues with the heat.
So to me it seams like there is a small 12V battery on board that should be charging any time the bike is plugged in but seems to be only charging when the bike is ON and plugged in. Does this sound plausible?
I was also thinking it could just be that the DC2DC can't put out as much power as the bike's battery voltage drops except that my commute is short and when I get home I am still at like 75% battery. If this was the case it seems like the bikes battery voltage would have to drop more than that....I was thinking the DC2DC was something ridiculous like 500W. If that's the case it shouldn't have any issues keeping up with this heated gear at all.
I am going to need to get to the dealer but the closest one is 97 miles away so I am holding out until I get my Super Charger late November. At least things have gotten better since I bought the bike and the closest dealer was 300 miles away.
UPDATE: I finally had time to remove the tank and do some more trouble shooting. Long story short, I had a cable with an SAE connector on one end from another project and I used it to connect the grips to the SAE connector on the bike. The old cable I used had a diode on the positive wire. The diode isn't necessary in this application but it wasn't hurting anything so I just left it there. Well, it turns out it was hurting. The diode has gone bad and is becoming resistive...creating a big load and pulling voltage down significantly. I had completely forgotten the diode was even there! As I was pulling the wires out of the bundle I felt the diode (it has shrink tube over it) and I immediately knew what was happening. I removed the diode and now everything is working great! Voltage stays above 13V even with the heated grips and heated seat at full blast!