Lithium Reg Pictures

Posted: under BSD General, On Road EV.

OK, I promised, so here we are:This is what turns out to be the bottom of the board where the interesting bits live. Reg BottomThis is the top of the board with the load resistors sticking up in the breese. Reg Top And how it looks mounted to a “Ligntning Bolt”Reg Mounted to “Lightning Bolt”

The stuff at the right end of the top picture, is the communication bits. The board will come in three flavors: 1. Basic, which just adds a 1 ohm load when the voltage goes above its set point, 2&3: Right and Left hand versions with the ability to talk to a charger, and tell it to back off on the current, when the voltage gets too high.

Why right and left hand versions you might ask? When you assemble a pack, you will have some cells with their positive terminal on the right, and some with the negative terminal on the right. This way, the communication bus runs across one end of the cells, so I need to stuff the comm hardware on one end or the other.

In the future, I might write software to allow them to talk using the comm bus, which is EVIL bus hardware compliant, but for now, we will use it to just tell the charger to back off when charge is completing, or to tell the driver or controller to back off when the cells are getting too low.

The three white blobs at the top of the first picture are LEDs that shine through the holes you can see at the bottom of the other pictures. You can’t see it in the bottom picture, but the right one is blinking green to say that the voltage on this cell is in the top 0.12V of the charge, before completion at 3.8V.

Comments (0) Oct 18 2008

BSD Lithium Iron Phosphate regulator.

Posted: under BSD General, On Road EV.

Are you thinking of using Lithium batteries in your next EV conversion? At around $200 per cell, you probably want to protect that investment. To help you, I just got the first pass of my Lithium Iron Phosphate battery regulator working! It is a 1 ohm load, that switches on at 3.8V. That is a similar amount of load to the Rudman MK3 regs that Manzanita sells for me.

They mount right to the top of a 100AH “Lightning Bolt” cell, and daisy chain to gether. When they are all hooked together, we should be able to control a Manzanita PFC charger with them.

The prototype draws around 1mA if it has a light blinking, which it does below 2.7V and above 3.68V, and about 3.8A if the voltage is above 3.8V. Between 2.7 and 3.68V it draws about 0.7mA (0.0007A). In a year, it will use less that 10% of the capacity of these batteries. I am pretty sure that is less than the self discharge rage of these things. I will get some pictures up soon.

To start with, I will be selling them through Cloud Electric Vehicles because they asked for them. I will also make a version for the ThunderSky cells too, probably through Manzanita but give me a little time on that.

Comments (0) Oct 17 2008

Jeffs Zenn #2

Posted: under BSD General, On Road EV.

Jeff has been driving his Zenn for 10 months now. He found that his batteries had about twice the capacity that the in-dash “Fuel Gauge” indicated, and that the BatMan3-EV was much more useful than what Zenn provides.

They had drained their batteries a bit more than they should have a few times. The problem would occur when they had been on a long trip, and they arrived at the bottom of the hill they live on with the batteries pretty tired. They had one case where passengers had to get out, in order for the car to make it up the hill. This probably is the reason that recently Jeff found that the capacity of his pack seemed to be falling. He brought his car over to my place, and over the course of a Sunday, I charged and discharged each battery individually to find the capacity of each battery.

My method was to use a power supply set to 14.76V to charge up each battery, just before I discharged it. I discharged the battery using a BatMan3-EL in drain mode, with a contactor connecting and disconnecting the 0.25 Ohm 1000W resistor, ending the test when the voltage comes down to 10.5V. This starts out at a bit over 40A, and as the battery gets tired, it comes down to around 33A. The BatMan3-EL records how long the load was connected, and how many Amp/Hours the battery produced in the process.

Here are the results, with battery, starting voltage, drain time, Amp/Hours:

1. 13.302V, 99:17, 58.46A/H
2. 13.298V, 91:15, 52.44A/H
3. 13.333V, 109:21, 63.09A/H
4. 13.328V, 101:19, 58.52A/H
5. 13.303V, 96:49, 56.49A/H
6. 13.260V, 95:20, 55.10A/H

Now we didn’t have the opportunity to do this test when the batteries were new, but we can see that battery 2 now has only 83% of the capacity of battery 3. After this test we adjusted the BatMan3-EV capacity in Jeffs Zenn to 45A/H to make sure they didn’t damage the batteries any more that they already had.

Comments (0) Oct 11 2008

Another Electrathon Record!

Posted: under BSD General, Electrathon.

Dave Cloud called today at lunch from Lewiston, Idaho. There is good news, bad news, and good news. The old Electrathon record was 53MPH, which Shannon beat. The bad news is that She didn’t win. The other good news is that Michael Lewis beat us AGAIN, while breaking his record by 5MPH, up to 58MPH! So that is going 58 miles in one hour on less power than a hair dryer!

That makes about 17W/H per mile. I call that efficient!

Comments (0) Oct 08 2008

Spirit of DC &

Posted: under BSD General.

Today was a busy day! It started out getting a couple of BatMan3-EV’s ready to ship. The problem was one of them was a new version with the DC to DC converter inside the unit. I suppose that shouldn’t be too much of a problem, all except for the manual.
I had to rewrite the manual, because the connections changed. Then I had to get some of them reproduced.

I also spent some time working on EVIL-USB adapters for Rich Rudman. The new versions seem to work really well, but the MK3 regs weren’t receiving from them very well. I also found that the new Reg Scanner software I had built wouldn’t talk to com ports above 9. This was a problem because the 5 EVIL-USB’s I had just finished building, ended up being com14-com18 on my laptop. So I fired up another project with my East Indian programmer to fix it, but he had the audacity to be asleep!

By then, it was time to wander into Seattle to meet with some SEVA folks, and meet EVJerry Asher who has been driving “The Spirit of DC” all around the country. The Spirit is a plug in hybrid Prius, and so far he has hit around 30 states, and a whole bunch of EV clubs. When I started this entry, he had moved on, and was just south of Tacoma, and now he appears to be visiting the Washington State Capitol in Olympia. You can see where he is by visiting his site: then going to MAP, and then following the big link “Click here to see the Spirit of DC’s current Location”.

Comments (0) Oct 04 2008