I'm not sure about the interrelation between these events and symptoms so I'll just list them chronologically.
MY xm-3000 did pretty well for the first 400kM. I could get to and from work, which includes a big 12% grade hill (which drops my MPH down to about 25). No problems. The only mod I have done to the bike is to add a PakTrakr and a logger (Logomatic from Spark Fun). I will post the data later today. I have not added charge equalizers nor am I charging with a bank charger. (Yeah, I know this would be best, but its a real PITA to install the 4 PowerCheks with very little space for them).
One day I decided how far I could go. 21 miles without economy mode, but I was in the red and one battery was down to 11.59 volts (this same battery was 20mV lower than the mean of the of other 4, open circuit at the start). It was not a happy place for the stack. This was at about 300kM
some short time after this (350Km), I rode in the rain. No problem. some short time after than I rode in the rain again with the headlights on (400Km). no problem, until I got home and realized I had not headlight, blinker, horn, dashlight, etc. I blew the fuse near the 60V-12V DC converter. So, I replaced it.
Between 400Km and 500Km I noticed a severe drop in the energy my stack is holding. I notice that once I am in the yellow under load, I am in the red under load in less than a minute. I have been using economode to limp into work (7 miles away with that big hill). It has saved me more than once.
I have also noticed that sometime between 500kM and 550Km my PakTrakr is claiming that all 5 batteries are overcharged. when I look at the voltage after a charge I read 65 to 68 volts. How can all 5 be over charged when the stack is only at 68 volts? is 13.6V per battery after a full charge not expected?
Last night was dangerous. It was not raining, but it was dark. Headlights on, in the yellow and red under load on my bike (coming home thank god)...all of a sudden the fuse blows again.I pull over, open the DC converter compartment and replace the fuse. Turn it back on...pow, blew again. apparently I went insane because I tried 4 more times and expected different results.
I noticed water in this compartment. There was virtually no water down in the compartment by the metal Dc converter (a couple of drops), but there was quite a bit on the 'shelf' below the hatch. I got to a nearby pizzahut and got some napkins and dried it, I tried without lights on. It worked, but as soon as I turned on a light or a blinker, the fuse would blow again. There is some SERIOUS current going through there, the spark that jumped when I accidentally touched the fuseholder leads together was significant.
I rode home in the dark with no lights and a scarily little amount of charge. Made it, totally illegally and with great discomfort about my safety (and everyone flashing me to turn on my lights, no cops whew!)
Questions:
Do we expect a stack to behave so poorly after 500km, this is about 20 days of riding and perhaps 30-40 charges.
What is up with the DC converter? Does it need replacing?
Could the significant current draw of the DC converter be draining my stakc and that is why my battery life is so bad?
Has anyone elses DC converter done this?
Would installing the powercheks help if I install them now?
I will post some graphs later. It will probably be more useful to discuss this then.
argh. Looks like when I looked at my logs from day 9 and 11 with the datalogger, I managed to change the baud rate, and every file since then (20 of them) are all garbage. That is really annoying, so I dont have any useful data during all of these catastrophes.
Well here is the data from the 21 mile day.
Its hard to read, I know. The voltages went like this:
The end of the end-of-day trip can be seen here.
This was the trip that 'seemed' to start the downfall of my stack. I say seemed becuase I am fully aware of how badly our personal perceptions affect actual facts.
As I said, all data after this was corrupted (dammit). but alas, I can not take new data about the stack performance until the DC converter issue is fixed.
I'll get a multimeter on the fuse line to see how much current is trying to go through that thing.. it may in fact have something to do with my stack life.
No one can help me or answer my questions in the first post?
Answers:
1. My first set of batteries in my XM-2000 went bad in this short a period of time. I put this down to two reasons (a) the batteries were old and not well maintained before I received the new bike; (b) I abused the batteries by over draining them. So, yes, it is possible for a pack to behave so poorly in a short period of time. Now, in your case, the batteries aren't old (check to see if you can find a QC sticker that will give you a date if you want to confirm that yourself). But they are out of balance and have been stressed harder than mine. FYI, my XM-3000 has 1300km and no battery balancing or charge balancing but I've ridden no more than 12 miles before a charge. (I decided to leave them without a balancer and with string charger only while waiting the BEQ's so I could see how well they coped).
From your posts it's unclear to me what your current range for the bike is? The quick decline from yellow to red that you quote can be indicative of a poorly performing stack. However, at the end of the day, your decrease in range for your required route is the best yardstick for your case. I'd suggest that you log your individual battery voltages during the charge cycle and the discharge cycle and then see how far they're out of balance while under load. It might also be a good time to contact X-Treme about warranty replacement. (Are you a customer of mine? Sorry, I can't always remember folks handles vs. true identity - if so drop me a line).
2. First off you need to determine if it's the DC-DC converter itself or a load being placed on the converter. Detach all the load from the converter and replace the fuse and power on. Does the fuse blow? If not then reconnect one load at a time (lights, turn signals etc.) when does it blow? These converters can malfunction - but normally I've seen complete failure rather than high current draw. If the DC-DC converter is bad X-Treme will replace it.
3. I know that the BEQ is supposed to help in this sort of situation where a string has already started to go bad - so I expect the PowerCheq's would help in the same way. The BEQ will do a better job because it can move more Amps than the PCs.
John H. Founder of Current Motor Company - opinions on this site belong to me; not to my employer
Remember: " 'lectric for local. diesel for distance" - JTH, Amp Bros || "No Gas.
Thanks john, so to continue....
looks like my current range is about 7-10 miles depending on when you think 'done' is. Pretty abysmal.
yes I am a customer of yours. This handle is attached to my blog handle and I prefer to keep it anonymous. If you need my real identity for anything I'll call you.
Sadly I can not do any more stack measurements until the electrical issue is fixed since the fuse blows. I tried the load by load testing, but any light (headlight, blinker, dashlight) will make the fuse blow. so I cant find a specific one. I'll try again this weekend. What is the proper size (amperage) fuse? Perhaps I am putting in the wrong one.
So i'm just waiting for my BEQ. I hope it helps, it sure looks easier to install than those powercheks (less wires and places needed to mount things).
I just sent you a private message - we can trouble shoot this together and then post what we find out back here when done.
John H. Founder of Current Motor Company - opinions on this site belong to me; not to my employer
Remember: " 'lectric for local. diesel for distance" - JTH, Amp Bros || "No Gas.
:) Hi Skeptic , Looking at your table , battery No. 1 if it is lead that bat. has one cell that is gone and a few that are going ! lookinh at your graf , looks to me as you have intermitent short in your wiring . I would do what he said !! do you have an amp meter ?? LaTeR
thank GOD I wake up above ground !!!!
thanks. Yeah something is wrong with batt 1. I'm hoping the batt eq will help with that.
I think you may be confusing the erraticness of the graph with an electrical short.
The update rate of the PakTrakr is 1 second. So those spikes are me going full throttle and letting go of the throttle.
As an interim measure (assuming that you are going to try using a BattEq or equivalent), try picking up one of the intelligent chargers (such as the Vector 2-4-6) and use it on each battery individually in an attempt to recover the battery. Since you indicate that you're using a PakTrakr, the wiring is most likely already in place that you need. Don't worry about disconnecting the batteries from each other - you'll be bank charging, just one at a time instead of all of them together. Hook up the charger and just let it run. It will automatically "turn off" (output will go to zero) when it detected a high enough output voltage/low enough current indicating that the battery is fully charged. It will NOT remain in a float charge condition - it actually shuts down internally. I have confirmed this by watching my stack reach a total voltage of nearly 74 volts as the chargers are in their final stage, then the stack voltage drops to roughly 66 volts at the end of the charge cycle. I have watched the chargers for several charge cycles, and you can hear the internal relays clicking within minutes of each other as they go from one charge state to the next (very close balance between batteries, even though the chargers are not perfectly matched).
I'm hoping for you that #1 battery will recover (even though it's probably already suffered damage) enough to remain operational. After you've charged #1, hit all 4 of the other batteries too. This will effectively "balance" the batteries for this charging cycle. I've been using the Vector charger mentioned above (a group of 5 ganged together) for over a month and the batteries in my stack seem seem to be doing just fine. Almost 700 Km on my original odometer, 250-something accumulated aH discharged, and it runs just fine. I have been religiously charging mine at the end of each operating day as soon as I get home from work. I thought my string charger had died and it was sent back in for warranty repairs, only to find that the string charger was fine and that I most likely caused the problem by not fully seating the disconnect plug (under the seat) for the charge receptacle. Once my string charger is back later next week, I will be opportunity charging the scooter at work during the day, and bank charging at night from home. It's only a 7.5 mile round trip, and I seldom go beyond 10aH daily usage - my batteries are not getting a heavy workout.
My scooter is registered in VA as a motorcycle, complete with tags and inspection sticker. I'm foolhardy enough to run this scooter as-is on the 35-45mph thoughfares in town, but would certainly welcome the extra speed I should be able to achieve with a higher voltage stack. The next time I am under the seat of my scooter, I will be taking measurements of the space available and possibly adding a 6th battery, much like John's pictures show when he added a 5th battery to his XM2K. It should be a walk in the park, since Xtreme basically did the same thing when they stacked one cell on top of the others like that already. I wouldn't expect any significant change in center of gravity for the scooter, but it will shrink even further the amount of storage space under the seat since it will require installing an approximate 1" spacer on top of the lower group of batteries to provide clearance at the battery terminals underneath.
Speaking of which, do you have access to these OEM batteries for a decent price, John? Want to sell one?
(No longer) XM3K, Bank charging using Vector 2-4-6 smart chargers, Cycle Analyst
Official member of the "I laid it down and I felt stupid" club
Check out the graph on page 2 of this article. That's what I use to judge state of charge. Just multiply the voltages on the left x5. From this graph you can see that it's possible for your 5 batteries to measure as high as 81 Volts while under charge at the C/5 rate (about 5.4 amps).
http://www.arttec.net/Solar_Mower/4_Electrical/Battery%20Charging.pdf
I've got 750 KM on my bike and the batteries are still holding up fine. I gave up using the charger they provided after my first one failed and have been using DC power supplies instead. I just set the current limiting and voltage manually to get the results I need. Usually a fairly slow charge overnight but faster here at work. Since the original charger worked at 4 amps I usually don't go above that. I also thought my DC-DC converter was bad but I didn't realize there were two fuses on this thing and one was just broken. It sounds as though yours may be pulling too much current and possibly faulty. I believe it was MrLadderman who got rid of his converter and added another battery in series instead. An interesting solution he posted here somewhere... I'm driving my bike 16 miles round trip to work but I charge it during the day, sometimes putting an additional 5 miles on it at lunchtime. All charging is just done in series, seems like too much work to set up for individual charging and monitoring...
I buy them via http://www.siliconebatteriesusa.com
John H. Founder of Current Motor Company - opinions on this site belong to me; not to my employer
Remember: " 'lectric for local. diesel for distance" - JTH, Amp Bros || "No Gas.