72v 35MPH xtreme xb 600!!!!!!!! Video link here.
I'm guessing that they're a bit cheaper. For some reason 20Ahr 12V batteries don't seem to be a hugely ubiquitous part. I've seen a lot of 18AHr and 22AHr batteries. I'm going with 18's myself simply because I found a good supplier (good prices and reputable) close to my home (within XB-600 distance) so I can save the $10+ in shipping each.
My theory is that I might be able to rig it up so that the 2 extra batteries (24V) will be somewhat separate from the original 48V. The idea being that I can save some modifications and replacements by just keeping the 48V wiring in as normal and then add the extra 24V only on the input wires to the controller. Again, I need to look at the wiring diagram and check some specs but it might be a decent trade off (read: cheap and easy way to do things). Though, I suppose this might be better posted as another topic at a later date.
Hi depetro,
I don't think your idea will really save you any money. You still have to modify the controller which is the biggest part of the 72V conversion. To keep the rest of the bike on 48 volt you simply need to wire in a resistor (like the one from Mouser Elect for about 6 bucks as Bocabikeguy suggested) You might check with Warren (Zerogas) on the exact wiring of it but his is working properly now since he wired the resistor to the original 48volt pack on the bike. Splitting up the batteries also forces you to charge seperately which is a drag and the different ah rating will drain the entire pack differently. Some things to think about I guess.
My experience going to 60V has been easier since the DC to DC converter is rated to 60V and I simply added another 12 20ah battery under the seat. I replaced my charger with a 60v from a XM-2000 and Voila! You would never know the bike is modded at all. My battery pack drains evenly since they are all matched (at least so far) and I am not so worried about burning out the motor on the XB. I don't think anyone really knows if that motor can take 72V for an extended period of time. Zerogas is the ongoing experiment --- kind of our EV Test Tube Baby!
Good luck on your mods.
Rob
Hey Warren,
Glad to hear 72V is treating you well. I'm going to pick up some batteries this afternoon and do 60V for a few days as I wait on parts (mosfets, caps, relay, etc) before going to 72V.
About those resistors, the color bands on them tell you the actual resistance. I can't read them from the picture, but here's a website that you can use to decode for yourself.
http://breakup.de/resources/resistor.html
Of course, you could just use a multimeter to check, but that's just too easy.
Also, how is fitting both of the 18Ahr batteries in the underseat compartment? Do they both fit easily?
PS: I'm cheap too and will probably just charge them with a single 12V charger and occasionally balance them separately as well.
Warren,
That amp meter is pretty sweet. I was wondering who'd be the first to put one in. How much was it and where'd you get it from? I'm pretty sure I'll be joining you at 72V by the end of next weekend. I just got 2 12V 18Ahr batteries today so I guess the extra $35 for the battery commits me to going 72V.
Out of curiosity, do you know what the original MOSFET part number is? I was wondering if those could actually handle 72V. I saw them the other day when I did the shunt mod but didn't get a chance to write them down.
that would be brown black red for 1k, and brown black blue for 1meg ohm
Tom
Hey Warren,
You beat me to it. I have the meter but just haven't had the time to put it in. :) Thanks for the wiring info. I will try to get to mine this weekend. Did you get the amp meter at the same place on ebay? Do you remember the link?
Your ride looks pretty slick.
Hey Warren,
I am thinking of placing mine even lower down on the main cover (kind of near your shins. There at least the angle is kind of towards you so I figure just glancing down you could see the numbers because of the angle. I am going the plug the unit in before I install to see the visibility angle on the lcd display. I don't need to look at the numbers constantly just once in a while.
Other place: what about just under the speedo? On the grey plastic. Is there enough room there for one unit?
Hey Warren,
Here is the Pic of the voltmeter: 
The only problem is that I have to waterproof the back because water could potentially splash up there. I have it covered temporarily until I do something more permanent. I will post a pic when I have that done.
This location is cool because you can see the numbers clearly when you glance down. I am waiting for the amp meter to come in and place it on the other side to have a nice matching set. :)
Rob
Hey Warren,
No it didn't come with a back. I a going to make one that I can mount to waterproof the whole thing. Working on ideas now.
I ordered the amp meter in blue as well. Hopefully it will be as bright. It's cool to glance down and see whats happening with the bike at any time.
It was pretty easy to install. Your wiring idea was perfect. I am going to run my cable from the 5th battery tonight so I will be ready when the unit comes in.
On as side note: Just want to remind anyone reading this thread to unplug the battery and leave the keyswitch on after you disconnected to make sure you don't leave any juice in the bike or you could fry something.
How's the Rad2Go going? Can't wait to hear how you make that work.
Hey Warren,
A 45lb backpack??? Is she going to Stone Mason School? Lugging home chunks of marble to do homework?....:)
Sounds like its going pretty good at 72V. Good to hear. 60V is still no problem either. I can't wait until my amp meter arrives. Quick question: did you attach the shunt for the amp meter to anything or did you leave it loose?
All the best
Rob
Found this also. Hard to find 16x3 tires. When needed I sure don't want the stock tire, too thin for the desert thorns in SW New Mexico.
http://www.motorcycle-superstore.com/5/32/404/5780/ITEM/Pirelli-ML-75-Rear-Moped-Tire.aspx
Happy scooting
JamesS
Well folks, inspired by Warren's actions, this afternoon I have officially joined the 72Volt club. I can now get it up to about 36mph. The pickup is a little lacking as my shunt mod is kind of a half a shunt mod (under sized paperclip and a cold solder joint) but the top speed is awesome.
Now I just need to put my bicycle computer on the bike and get an amp meter and it'll be all finished.
Oh another question, has anyone running 60V+ tried to modify the existing voltmeter on the dash to more correctly show Full and Empty? I know the speedometer has a potentiometer on it that allows you to adjust that (don't adjust that, its a pain) but I'm wondering if the stock voltmeter can me modified to show F/E for 60 or 72V.
Found this also. Hard to find 16x3 tires. When needed I sure don't want the stock tire, too thin for the desert thorns in SW New Mexico.
http://www.motorcycle-superstore.com/5/32/404/5780/ITEM/Pirelli-ML-75-Rear-Moped-Tire.aspx
Happy scooting
JamesS
I measured the rim diameter on my XB-600 front wheel, and it is 12 inches, not 16 inches, although the tire is clearly marked 16 X 3.0.
I am very confused.
Just thought y'all might want to know,
Tom
Hello Tom,
I measured the rim diameter on my XB-600 front wheel, and it is 12 inches, not 16 inches, although the tire is clearly marked 16 X 3.0.
I am
very confused.
Just thought y'all might want to know,
Tom
Yea me too... Try searching for 76/305 that follows the 16x3 on the side wall of the tire and you get nothing.
I don't need tires yet as far as tread goes but, the original ones are so thin that I have to run slime tire sealer in them. Thats fine in the summer but in the winter if it freezes then it tends to throw the tire off balance very bad. I am going to start a new thread for tires if you would like to continue this topic.
Happy scooting,
JamesS





Hello all,
Day 4 at 72v commuting to and from work. The 2 new batteries did the trick. I didn't charge at work and had plenty of power to get home. The 18ah batteries are rated low, they are more like 21 or 22ah batteries and at $45 each at Interstate Batteries, They work out cheaper than those from extreme and I don't have to wait for them to come in. As for charging, I unplug the spade connectors where I ran my wires up through the seat and connect the 48v pack back together. I charge it with the stock charger. For the other 2 batteries I switch 2 wires to make them in parallel (12v even though they are 2 batteries) and charge them with a separate $28 schumacher charger I bought at wal-mart. Yes, I'm too cheap to buy another $28 charger, LOL. I charge them in parallel with one 12v charger. This mod was well worth the trial and error. The bike is sooo much better now. I have noticed one thing though. My rear wheel isn't aligned correctly and my back tire is almost worn smooth. :( That's next on the list along with installing my voltage and amp meters.
-Warren
Keep the rubber side down and the shiny side up.