Sunday 21 December 2008
Saturday 20 December 2008
Friday 19 December 2008
Monday 15 December 2008
This weekend was spent making up fuse boxes. I purchased 60 FHM3AG fuses from Pacific Components .
26 of these are to connect to the outputs of the 13 chargers. These (actually 24) of them are mounted in 2 ABS boxes on clear acrylic. The final 2 will be inline as they are only +-12 volts.
Each alternate fuse has 48 volts between them so before inserting the fuses I will glue some clear plastic sheet between them so they don’t short when fumbling with fuses.
I started test charging one set of batteries and unfortunately the charger let the magic smoke out of the output electrolytic capacitor and a diode also ruptured. I have replaced the cap and diode, but the charger still has some problems. Back to e-crazyman on eBay if I cant fix it.
Another smaller ABS box has 6 fuse holders for the heater and the 12 volt power supplies to charge the accessory battery.
Tuesday 25 November 2008
Monday 24 November 2008
Take a look at http://productivemagazine.com/editions/
Sunday 23 November 2008
I have used one of the spares as the 12 volt battery for the accessories. To fasten it I bought some 6mm threaded rod (600mm zinc plated for $2 from Hardware and General) .
I cut it to length and bent about 30mm on one end 90 degrees. The bent end goes through a 6mm hole drilled in the base where the original battery went.
The battery is sitting on a rubber mat. The threaded rod and the hold down clamp are covered in heat shrink to prevent any possible abrasion.
The cables are 16mm^2 . Overkill but free. The contactors along the side are double pole. These are used to break the battery bank into 12 x 48v blocks and on 24v block. This makes it save to work on. I tested each contactor separately with my cable shears at the ready in case I had made a terrible mistake. Thankfully they were not required. Across any contactor there can only be 48v max so it is safe to work on. The stainless steel battery clamp strips are covered in heat shrink to give as much insulation as possible. Each battery has the zener-resistor balance circuit connected across.
Next step is to put the +- 300v cables and interconnects to the VFD into orange plastic tube. and begin connecting the controls. (throttle, reverse lights, direction switch and VFD display. Then the chargers and fuse holders for the chargers.
Saturday 15 November 2008
Thursday 13 November 2008
There was a very good turnout for the presentation this evening. And quite a few AEVA members as well. Many of the IEEE members were keen to hear about the various conversions underway after the main talk.
Andrew brought his motor bike along that drew a good amount of interest.
I should have printed some AEVA 'business' cards to had out.
Roy gave an excellent talk on his various EV designs and also briefly descried a business he is setting up and was receiving expressions of interest for people to become a part of the company.
He described various sized family vehicles as well as buses of all shapes and sizes, including a double decker the size of a B Double.
Unfortunately there is not a web site. I found this by google that discusses some of his projects. http://eclipsenow.blogspot.com/2008/08/double-decker-trams.html
Sunday 9 November 2008
Yesterday I installed it and the VFD in the tray. Beneath the trey there are 4 stainless steel square tube cross members to help support the batteries, act as spacers for the bolts to the trey structure and to support the VFD.
Essentially the CO2 emissions are about the same for an ICE for a similar weight vehicle.
So, even using power from a modern coal fired power station, the environment is winning. Also the point of combustion is away from populated areas.
Thursday 25 September 2008
Gotta love the internet!
Tuesday 23 September 2008
Monday 22 September 2008
3 tips if you go to the ports.
1. Wear a fluro vest
2. They don't load vans with a forklift
3. You are not supposed to break down packages for loading.
None of this was a problem but I will keep it in mind if the is a next time.
So... the final outcome
55 batteries AU$2290.48
Bank Fee AU$ 20.00
GST and Duty AU$ 423.77
Customs Agent AU$ 137.5
Port Fees AU$ 248.05
TOTAL AU$ 3119.08
or $56.72 each.
Tuesday 9 September 2008
Friday 5 September 2008
Tuesday 2 September 2008
Here are the details of the heater install.
The heater is designed to run 4 ceramic elements in parallel at 240VAC
I will be running the 4 elements in series at 600VDC. If they were purely resistive this would amount to about 800W.
But these are PTC so I expect the output will be a bit higher.
The element has been installed in high temperature RTV compound into the main air duct from the fan.
The relays for the heater are only able to be energised when the fan is on.
<<30072008.jpg>> <<30072008(002).jpg>> <<23082008.jpg>>
A thermal cut-out on the heater, connected to the relays coil will also be installed for protection in case of over heating.
Here are the parts for the battery balancer.
They are all available from http://www.rockby.com.au
For the 50 batteries, there are:
· 100 x 5mm Terminals
· 100 x 6.8v 5W Zener Diodes
· 50 x 4.7R 1W resistors.
I will make up a jig to assist soldering them all quickly and accurately.
After completion they will be encased in heat-shrink.
- My batteries are on a ship on their way from China. Should arrive mid October.
- Spent Saturday installing the dashboard and stereo. Gotta have good sounds!
- I have located all the important wires in the loom and designed the necessary opto isolating interface. (Reverse, Tacho and Speedo)
- I have permanently wired the brake vacuum pump to the ignition
- Sent plans for battery box to Geoff for fabrication.
The aluminium block holds the inductive pick-up. (Thanks Geoff)
The drive flange is the grey part.
The Universal and sliding spline are bolted to the drive flange.
I spent ages looking for 10mm x 1mm pitch bolts. I should have gone to Toyota first. They were just a couple of dollars each!
This is the rear mount that attaches to where the gearbox used to attach.
Sunday 10 August 2008
Director of R&D, Greensaver: "Two comments on the cycle life test result: (a) The cutoff voltage was too low. Overdischarge will cause low cycle life. It is suggested that the depth of discharge is limited to 80%, and the cutoff voltage is set at 11.4 ~ 11.5V.
Point 2 would be difficult to implement due to the cost, size and primary current of chargers.
The capacity is normalised to 1Ah discharge as varying discharge currents were used. This eliminates the effect of the Peukert factor at different discharge rates. The 'waves' are caused by slightly different end point volatages at different currents.
Tuesday 5 August 2008
Last week I ordered 55 x Greensaver SP20-12 batteries. 50 to install and 5 spares.
I need to design and build the battery box next!
Cost per battery should be a little under $60 each including landing taxes.
Thanks to Geoff O'Toole for your fantastic machine work.
Here is a photo of the drive flange assembled with the inductive pickup (AE1-AP-4A) from AutomationDirect.com.au.
The speed sensor is used to provide feedback to the controller for closed loop operation.
The Drive Flange has been machined, drilled and tapped to accept a Hilux universal joint.
Thursday 17 July 2008
Average = 2.097083
Standard Deviation = 0.003079
Range is from 2.0919 to 2.1004 difference = .0085 volts (0.406%)
Again the battery seems to be well balanced.
Wednesday 16 July 2008
Tuesday 8 July 2008
They provided the following diagram of the top of the cell including the interconnecting links.
I drilled 5 holes in the top of the battery according to their diagram and measured the voltage of the 6 individual cells. The battery is measured at full charge. This battery has been (unfortunately) over discharged about 35 times and is only about 1/2 new capacity. A battery that has been cycled like this should exhibit significant imbalance between cells if the cells are not almost identical.
The results below are measured with a meter (not pictured) with 4 decimal places:
Cell : Voltage
Average cell voltage is 2.2466 volts. This is 100% charged including some surface change.
The standard deviation is .004616
The range is from 2.2402 to 2.2541. A difference of 0.0139v (13.9mv) or 0.6205%
I am not an expert in battery chemistry but this seems to be quite good.
The pump is quite quiet. At higher vacuum the vibration is less.
From left to right:
1. T goes to brake booster and to the vacuum tank. (Aluminium drink bottle from Katmandu)
2. T and vacuum cutoff swithch
3. T and vacuum gauge
4. One way valve
5. Vacuum pump.
I bought the brass fittings (5/16") from ENZED
Monday 23 June 2008
I have fitted a forward, neutral, reverse switch and the display/keypad for the motor controller. I am VERY pleased how these worked out.
I fabricated what was needed from scrap aluminium. All in all I am happy with how it turned out. Placement in the engine bay is a little awkward due to the limited length and the stiffness of the cable.
The rubber dust boot should be pushed back over the cable shroud.
Thursday 19 June 2008
Electric motor and ICE side by side
The curb mass including Driver and a 1/4 tank of fuel was 1340kg
780kg on the front Axel and 560kg on the rear. (58%F 42%R)
There was a total of ICE components 285kg removed
This leaves a vehicle mass of 1340 - 75(me) -285 = 980kg before installing electric components.
Wednesday 11 June 2008
It is a Danfoss VLT6042 30kW 380-500v unit. It is in an IP54 case.
It has the DC bus option so it can be powered directly from a ~600v battery pack. According to Danfoss it can be lighted by (~20kg) removing the AC input filter components.
The Danfoss tech may also have a PCB to upgrade it to a VLT5032.(lower number, higher spec)
See here for images
Here is a link to the Specifications and Manual. (look for the VLT 6000 HVAC)
It is suitable for a conversion where you will retain the gearbox in a larger vehicle or a small vehicle with direct drive.
Please drop me a line if interested. (m.faed at ieee.org)
|Accessory||Current Draw||Include in Max total|
|Dome Light||0||Needs Bulb|
|Total Draw Amps ||46.2|
As a consequence 2 modifications were required.
1. The feedback circuit needed changing to increase the adjustable output to 13.8V. This was done by tracing the voltage divider circuit and adding the required resistor in parallel with an existing resistor.
2. The 20 ohm bleed resistor needed removing in order for it not to discharge the battery while the vehicle is not being driven.
The image below shows the modifications. (zoom in for detail)
The completed power supplies have been installed into the Variable Speed Drive where some of the AC filter components have been removed. The device between the power supplies is a 50A circuit breaker that will be used for the 12V protection. The Power supplies will be wired in parallel.
There are 2 x 6.8V diodes and a 5 ohm resistor across each battery.
(Thanks again for the info from Tuarn)
The Lead Acid batteries at rest are about 13.3V at new and fully charged so no power is lost when the batteries are not in use.
The Zener voltage must be greater than the battery full charge voltage
The idea is that the more voltage there is across a battery, the more current is bypassed that chargers lower batteries.
This worked surprisingly effectively.
The batteries before installing the balancer were from 12.5 to 14 volts at 'full' charge.
After balancing they were all within a few millivolts of each other, even after some discharge.
I was concerned that the bypass current may effect the automatic charger cutoff point as the batteries became fully charged however the charger still functions properly.
Given Zener voltage = 13.6
Maximum charger voltage = 15.2
Bypass resistor = 5 Ohms
The maximum current through the resistor is (15.2-13.6)/5 =.32A
The maximum resistor power dissipation is .32 * (15.2-13.6)=.5W
My ceramic 5W resistors are overkill. I will use 1W resistors in the vehicle system.
Maximum zener power dissipation will be 6.8V * .32A = 2.2W
Microprocessor controlled battery discharger and charger.
4 x 1 Ohm 200 watt resistors. Hard wire configurable.
Relay to switch between 2 discharge currents
Microprocessor calculates V, I, Temp, Ah, Wh and Peukert Factor.
After discharge, the battery is automatically charged.
The discharge cutoff voltage is programmable.
The negative figures in the LCD indicate that the battery is being charged.
I know, it looks like a weapon of mass destruction :)
To determine the Peukert effect of the 20Ah and 27Ah Greensaver battery.
The reason for perform the test is because the specifications state a low Peukert factor fro these batteries and I wanted to verify this before purchasing a pack of 50 batteries.
Discharge curves. (note glitch in V5 between seconds 3 and 12. As this is only a 9 second occurrence, it does not affect the overall result.
The average Peukert factor of 1.105 is low compared to other batteries that are usually greater than 1.13 for batteries of similar capacity. The calculated Peukert factor from the 20Ah specification sheet is 1.07. My tester is probably not that accurate but is sufficient to confirm that the battery performs close to specification.
Given this result, if Lead acid batteries are used, they should have superior performance under load and give a long service life.
Original discharge data is available in an Excel sheet upon request.
I also have a 27Ah battery that will be tested next.
The high current wiring will be upgraded to allow testing at 40A
The discharger will also be reprogrammed to continuously charge and discharge a battery to determine de rating over time.
The charge curve for the 20Ah battery is below.
Thursday 29 May 2008
I had considered these ideas at different times but Tuarn rolled them up into one nice post.
Lower viscosity oil in the diff will be a must. As per Tuarn I will look for 55W75.
Setting the tow in will be important. Lower the better within reason.
Tyre pressure is a given. I will try and locate the Rolling Resistance specs for my tires.
Now the tricky part. How do you minimise brake drag. The rear drums are self adjusting and the front are disk brakes. Neither lend themselves to tweaking. Any tips and suggestions welcome.
At some point I will get some 'moonie' hub caps / wheel covers. Partly to reduce wind resistance and partly for looks.
1. I received the Greensaver batteries (20ah and 27ah - 2 hr rate). The port chargers were unbelievable! These would have to be the 2 most expensive batteries in Australia! Lesson learned about sea-freighting goods
2. I have built a micro controller based charger / discharger. It will measureand log to a PC the following aprameters during discharge and charge Volts, Amps, Watts, Ah, Wh, temperature and the all important Peukert factor. It uses 4 x 1 ohm resistors. The resistors can be wired differently to vary the test current. I am waiting an LCD from Futurelec and a charger from ebay's ecrazyman.
3. I have bought a diff from pick'n'payless . It is a 5.125 ratio from a Hiace van. All going well I will install it this weekend. This gives a theoretical top speed of 94km/hr at 4000RPM
4. I also bought a manual steering box from pick'n'payless for installing this weekend.
5. Better VFD. I bought a better Danfoss 5042 VFD off ebay. So, if anyone wants a Danfoss 6042VFD in an IP54 case I have one looking for a home. I have removed all the AC components from the cabinet to minimise losses and will feed it DC directly to the soft charge circuit.
6. The ute has a tray back which was way too wide for the body. To tidy up the looks I have narrowed the tray to be the same as the body (100mm off each side) and shortened the back. If I need sides I can get them from the manufacturer which is encouraging.
At the moment the carport looks like a car wreckers yard, but things should start coming together in the next few weeks. I am still waiting to borrow an engine hoist from my neighbours.
Monday 12 May 2008
The brakes look OK. The diff needs replacing. Just as well I planed to change it to a lower ratio.
The next few weekends will be spent fixing up the body paintwork and surface rust spots.
Friday 2 May 2008
Monday 28 April 2008
I have also ordered 4 x 1 ohm 200w resistors for building a battery analyser. I am workon on the Bascom AVR code at the moment to check their capacity at different loads. The Peukert fact er of 1.09 for the 20Ah unit seems a little too good to be true but if it tests out after many cycles then they are great value for a bit over USD20.
Wednesday 23 April 2008
The speedo just requires a 4 pulse per revolution input from the shaft.
There is a pulse output from the Danfoss VFD that is programmable. I will also be able to adjust the VFD output to compensate for the change in differential ratio.
This setup will require that I use closed loop control to have an accurate speedo.
Monday 21 April 2008
Saturday 5 April 2008
As there are 50 units the price could be quite significant.
Ideally a microprocessor based system would be implemented with isolated sensors on each battery however at this time it is cost and time prohibitive.
There are 2 alternatives I have seen the first would place 15V Zener Diode in series with a light bulb or suitable resistor across the battery. When a battery exceeds 15 volts, the Zener and lamp would bypass current proportional to the over voltage. This would be the simplest to implement.
Another alternative is a more aggressive voltage clamp described here.
The clamp voltage will have to be above the maximum charge voltage from the chargers and the regenerative braking.
Under regen this is 15 volts. Under charge this is about 15 volts but will need to be measured on the charger.
Obviously this solution will only work under charge but should be sufficient for now.
I will test it on my self balancing scooter first.