I don't think you have many good options here, short of starting over and doing it right, but here are some comments on some of the components you already have. Your batteries are likely toast. You can spend hours weeding through them and picking what seem to be good ones out and trying to replace the bad ones, but most peoples experience with lead acid battery packs proves that once part of the pack goes the rest usually follow, especially when it is an unknown pack which has been abused in unknown ways.
Yes, the 72 volt alltrax should have enough ooomph to drive in traffic and speeds up to 45 mph and up small inclines provided you still have a transmission in the car. I started out with one of these in my 1970 Datsun truck and drove it in similar traffic. The truck weighed about 2300 pounds at the time and I have the original 4 speed manual transmission. Performance was modest, but did not feel dangerously slow. It was fairly similar to the little 4 banger that came in the truck. I do have one large hill near my home with a couple of stop lights on it. The second light is towards the top of the hill but rather steep and I did not like not being able to accelerate up to speed (35mph) before crowning the top of the hill although I have been behind many gas cars with the same problem. I also use a 6.7 inch motor in my truck and it works just fine at all speeds, so your motor should be able to handle your modest requirements as well. However, both your motor and controller will need to be cooled. You are working them hard, so you should have the controller on a proper heatsink with some airflow and you should be forcing air through your motor with an appropriate blower. This is especially true if you are going to try to drive 50 miles. The longer the drive the more heat build up there is that needs to be dealt with. Of course for these components to work out the car needs to remain lightweight, and there is no way you are going to get 50 miles range and remain lightweight with lead, so you are now talking about a few thousand dollars in lithium batteries. Once you have spent the money on the batteries it makes using this just adequate motor/controller combo kind of silly, which brings us back to my original assertion that your best option is to start over and do it right... larger motor, higher voltage/power controller and lithium batteries. If you only needed 15 - 25 mile range then you could stick with lead acid batteries and the current components and get off fairly cheap. I do not see how you can get 50 miles range with lead and the current controller/motor combo with anything but abysmal performance however. The car would be too heavy and the drivetrain too underpowered. damon > Date: Thu, 23 May 2013 07:45:56 -0600 > From: [email protected] > To: [email protected] > Subject: [EVDL] e-volks upgrade.... > > So... a client of mine got a converted VW bug with the wilderness EV kit -- > the kit#2, so it's a 6.7" series DC, 450 amp alltrax, 72 volt system with > six 12 volt 100AH gel batteries, no DC-DC, very little instrumentation, > crude offboard transformer 10A charger. Right now, the car can move > itself around the yard, and that's about it. They said they did get it up > to about 40mph on the flat before it died though. Only 20mph even on very > slight upgrades. > > Here's what I'm thinking of for upgrades.... they want a good solid > 50miles range, and enough speed to keep up in city traffic (45mph, a few > small hills, but not climbing big ones). > > Figure out if any of the current batteries are any good.... (some are brand > new, so they should be). > > Better charger (not sure the old one is working at all, which could explain > why the main bank is not doing well). > > Think about lithium batteries/smart charger/ and higher voltage > > DC-DC converter > > Is the Alltrax any good? or should I think about a better controller? It > looks tiny for a roadgoing EV, no heatsink even. This one can't take > higher voltage anyway. > > Lithium batteries? Not sure that getting solid 50 miles on lead is > possible in this car without seriously overloading it. > > Is the 6.7" series DC motor enough for this heavy of a car? > > some sort of metering such as e-meter at least, aux battery voltage (it has > main battery volts and current, which I'm not sure are even working). If I > go with lithium the BMS will probably have a good amount of monitoring > available. > > The bug was completely restored, so even if I have to replaced every single > EV component, it was still a great deal for the price they got it for, just > for the donor car. > > Also.... I got to test drive a ford focus EV yesterday -- just happened to > run into Ford's traveling EV/hybrid show while grabbing lunch at the > shopping mall. It is a sweet car. Being mainly a compliance car, it > seems, I wasn't expecting much, but I was pleasantly surprised. It was > quick off the line, good regen (controlled by the brake pedal, not the gas > pedal), handled well, though it did feel a tad heavy for that small a car > (but I've driven new ICE cars that felt really heavy for their size too). > Dizzying array of gauges and screens inside. I like the concept of the > butterfly gauge. If you drive more efficiently than average, you get > butterflies that fly around one of the display screens. If you brake to > fast (less regen captured) or accelerate too fast, and drive less > efficiently than average, it takes butterflies away from you... kind of > neat game to keep people from driving inefficiently. I thought that was > interesting playing on people's emotions not to kill their butterflies > rather than giving them a cold efficiency number that most non-engineers > will just ignore. The biggest thing I was surprised by was the trim level > and features were way nicer than my new prius -- though, for twice the > price, it better be. Also had the C-max plug in hybrid (20 miles EV range) > which I didn't even know existed... didn't test drive that one. They don't > have an EV certified dealership in Denver yet so you can't actually buy one > here, but soon, they said. Much nicer car than the iMiev, for those who > can afford it. I haven't driven the Leaf or Tesla S, so I can't compare to > that. > > Z > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: > <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20130523/4e278238/attachment.htm> > _______________________________________________ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > For EV drag racing discussion, please use NEDRA > (http://groups.yahoo.com/group/NEDRA) > -------------- next part -------------- An HTML attachment was scrubbed... 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