Hi, I’m very excited to find this forum. I’ve been driving, and towing my ev for six days now. I have a 1986 Civic Hatchback with a 72v pack. A solid starter car and I love it, but I need to make some adjustments and upgrades both to the car and to my driving/maintanence.
First off I was told it could get 35 miles per charge under “moderate” driving conditions, which apparently means downhill with a tailwind. I took that with a grain of salt, expecting 20. I’m getting 14, even on flat roads staying under 40mph. My goal is to get it to a reliable 19 miles per charge to get my wife to work. I only want 5 more miles. I’m sure thats a common refrain. My driving can certainly improve, but I understand the concept and am working on it. I’m using an offboard charger and intend to buy something better when I’m sure I’ve got the batts sorted.
Where should I start looking to improve to get that 5 miles?
Very standard conversion originally from Wilderness Conversions:
D&D 72v series wound motor (up to 120v)
alltrax 72v 500amp controller
9 x 8v Golf cart batteries EGC8 flooded with around 60 cycles on them
Have you looked at Optima batteries? I don’t know how they compare to golf cart batteries. I replaced the starter battery in my car with an Optima, and the Optima only weighed about half as much while being more powerful.
My sympathies to you. I drove mine 30 miles today before it went down. I parked it at a store about 1 mile form my house, If the road was not tore up and shut down one way I would have made it home easily. But I have to go three miles around and it wouldn’t make it today, this is the first time I didn’t make it home while out. The car might have to be trailered this time. I have found that running at a higher rpm gives you added miles, but you have to be careful not to over rev it. It will go as fast as the next higher gear at a lower amperage. Take advantage of coasting on the downhill. as this shuts the secondary contactors at no cost to your power pack. Good Luck to you. Also the freeway seems to really eat up power. Check the air in your tires, you might be able to get less rolling resistance with a higher pressure I run mine at around 45 psi. See if there are any more lbs you can remove from the car. I am running a 144 volt pack so maybe 15 miles is right.
The Optimas do look good but I’m going to run these Energizers into the ground first before buying a new pack. Me and my wife have our first baby on the way.
Yeah, the tires are a very good idea. I spent all day checking my connections and redoing the ones that looked questionable. I could’nt find my FLUKE so I bought another tester, and my batteries are all a little low but within .5v of each other. It has got to be my charger. From what I’ve been able to gather, I should be getting 2 miles per battery at the very least. I’ve been wanting to put in some sort of onboard charger anyway, so that’s next.
If you’ve got a baby coming, your only option is to cut out the floor and go Flintstones :eek:
After waiting for a couple of hours I went back and got the car home ok that night. LOL
[QUOTE=new dawn;713]After waiting for a couple of hours I went back and got the car home ok that night. LOL[/QUOTE]
Awsome. I’ve got my range up to 20 miles if I really pay attention to my driving. And that’s not too shabby for 72v. Most of the trouble is my charger, but airing up the tires properly helped a little too. Thanks new dawn!
I’m trying to put together a 72v onboard charger for a couple hundred bucks, I’ll let everyone know how it works out.
How big are those golfcart batts? What about adding a couple? Your voltage will go up some, but more importantly so will your range.
[QUOTE=inSANe DIEGO;720]How big are those golfcart batts? What about adding a couple? Your voltage will go up some, but more importantly so will your range.[/QUOTE]
9x8v RC minutes @25Amps = 290 / Minutes @75Amps to 5.25v = 110
I’m on a budget and my controller is only rated for 72v. I know a lot of Xebra owners (I have the same controller) are throwing an extra 12v on there with no problems. I think the controller shuts down at 90v.
I’ve been thinking about how to do the same thing, but I don’t have a way to charge the extra battery unless it’s a 12v. Could I add a 12v to my 8v pack and charge them seperately? What would really happen?
Voltage Voltage Voltage!!! Higher voltage = less current given the same wattage requirement. The less current you draw the longer the batteries will live, and last. Most motors can handle higher voltages then there rated for. My motor, for example, was rated at 72v. I ran a 120v (12v x10) pack and never had a problem. It was also rated at 102 amps and my peaks were >400 amps. The motor got warm but I could touch the armature and hold my hand there.
Your speed control should limit your maximum current draw. Lets say 400amps. If you raise the voltage it will hit 400amps with a narrower pulse. Instead of sending 70% pwm for 400a, it may only need 50% pwm when using a 120v pack. Either way the motor sees the same averaged wattage.
I’d crunch the numbers for you but I don’t have time atm.
Tire pressure has already been mentioned but one item that’s often overlooked is alignment. I cranked all the toe-in out of my mini-truck and noticed quite a difference (seat of the pants). It does wander just a bit tho.