Sv: DN: "Think konseptet er dødt"

[Ken]

You could try and measure the amount of current that is drained from the 12V battery. The BMS takes some and maybe your radio takes some as well.

Think cars are known for this but there are several things that can help the situation.

Change the 12V more often. The battery should be in top form. Use the old one in your elctric lawnmower!

Plug in an automatic charger in the cigarette lighter plug espesially if you are going away for a few days or more. Once the main battery is drained, then the DC/ DC won``t come on and charge the 12V and damage will occur due to sulphation. I try and wait until the waterpump is off before connecting the charger so that there is no conflict between the DC/ DC and the auxillary charger.

Eliminate any unneccesary parasitic loads on the battery.

I am not sure whether the DC/ DC  charges the 12volt under charging of the main  battery. It often seems as if the 12V is charged after the power lead is removed from the car.

I wonder if a bigger 12V would help the problem. NiCad and NiMH would be better in cold weather as well. Maybe with these battery types one could use a smaller pack. The charging parameters would be wrong though.

Most of us Think owners live with this problem but we wear out parts such as the water pump more quickly.

Info freely given!

[ilmarw]

cra - the program is closed - I am not planning to provide the source code. Unless someone convinces me otherwise. If you would like to write your own program I am planning to provide a c++ dll, which one could use to make his/her own program for display.

Are you planning on selling a product based on this code? If not, making it available for others would benefit electric car owners all over. Instead of explaining why you should make the source available, I am going to ask: why not? One reason for making it public is that there are probably a bunch of people who could actually help you with developing the code even further, for free!

If you are planning to make a product for sale, this still does not mean you cannot make money by making the source code available.

ilmar

[El rayo]

Today I noticed that because of the low temperature (1C) when the car is turned off the accessory battery voltage goes almost immediately below 12.5V, which in it's turn switches on the charging of it.

I've asked several mechanics who work with Th!nk how to figure out if the 12V service battery is bad, but noone can tell me. There's nothing about it in the service manual. Someone here at the forum said the water pump and DC/DC should not start during the first 1 hour after the car is switched off and the headlights are left on.

If the voltage drops imideately when you swith off the ignition it indicative of a defective/worn out service battery.

On my car with Defa alarm and non original radio I measure 112 mA current from the service battery when everything is switched off.

The charging of the accessory battery (in my case) takes approx 1A from the main battery pack (127V),

Same as my car.

My battery is 1 and half year old (from biltema), and I have been very nice to it.

The battery may have been stored too long and/or too warm before you bought it. I replaced my service battery March 2005 and it's already giving signs of severely reduced capacity. The DC/DC and water pump starts within one minute with headlights on and everything else off.

[BauDemo]

I am not sure whether the DC/ DC  charges the 12volt under charging of the main  battery. It often seems as if the 12V is charged after the power lead is removed from the car.

The 12V battery is charged during charging of the main battery pack. The voltage reported is around 14V.
I found couple of interesting alternatives.. check this:
http://www.thunder-sky.com/products_en.asp?fid=66&fid2=82
and in particular these two:
http://www.thunder-sky.com/pdf/20081122102212.pdf
http://www.thunder-sky.com/pdf/2008926101523.pdf

My default "plan" is to provide the program as shareware, the reading of parameters functions will be free of charge. The playing around with error codes and other "advanced" stuff may be for small shareware fee. I spent extensive amount of time and money in making this possible and although I made it for myself, it would be nice to recoup some of it. These are just a random thoughts – I may end up with a very different license and solution.
I haven't given much thought on open source - I do not feel that I need help developing the program - I make living writing software.
I however think I need help in figuring out what the program should do to make the life of a THINK owner easier.
I have already started on functions for calculating the battery pack internal resistance, few ideas for alarms when some parameters do not correspond...

Ilmar, if you have any personal experience with releasing software under open source, I would be happy to hear it...

If you are planning to make a product for sale, this still does not mean you cannot make money by making the source code available.

Can you please elaborate, what would this business model be?

[Boogie]

For the PSA cars, we normally make a capacity test of the 12V battery when we do water service. If the capacity is below 8Ah we replace it.
This could ofcourse also be done on the Think cars, but it is a little bit more complicated to remove the front to do a test of the battery. But ones a year does not hurt.

For a 44Ah battery we use 25A load, and stop at 10,5 V.

[El rayo]

The 12V battery is charged during charging of the main battery pack. The voltage reported is around 14V.

From what I recently learned from the Norwegian model airplane group, a 3 cell, 11,1V LiPo battery can be charged by an intelligent lead/acid charger. Max voltage is 14,4, the same as Th!nk delivers to the 12V battery with the ignition on. NOTE: The LiPo battery still needs a balancer to insure that no single cell gets too high or too low voltage! Otherwise the LiPo will catch fire. A protection against physical damadge caused by a collision is also strongly adviced as that will cause a fire, too.

In my opinion the original lead/acid service battery is still the most cost/effective solution if you are able to replace it yourself about every 3 years.

Edit: Burde selvfølgelig sjekket linkene før jeg postet
Dette ser ut til å være en annen lithium kjemi enn det jeg kjenner fra før. 10 - 17V arbeidsområde!?
Men hvordan skal man tolke dette: "Please connect the battery to the cathode and anode connection port of the 12 V Lead-acid battery that it replace for."

Have you got the price for these batteries?

[Rav4_EV]

Disse batteriene er ikke noe nytt. 4 Thunder-Sky celler i serie.

10 -17 volt. Deler du på 4 får du vanlig TS batteri spenningsvindu. 2,5 - 4,25 volt

Uten balansering får de muligens et kort liv.

Så lenge det ikke er "gammeldagse" li-ion med koboltoksid blir det neppe noe fyrverkeri ut av de.

AM

[BauDemo]

Have you got the price for these batteries?[/i]

Sorry, don't have a price - this was just an example of a product that may be of interest. There are similar products by the other big Li producers. There is also the Firefly Lead foam battery... only time will tell. I will see if I can fish out some more info.

Disse batteriene er ikke noe nytt. 4 Thunder-Sky celler i serie.

hihi - well...
- "new" is a matter of perception. The last version of the battery is from May 2007 I believe...

- as you say - these batteries are simply cell connected together... they are packed in "common space" (whatever that means),  they are not good for electric vehicle propulsion though. Only for accessory battery.
Here is more info from the factory:

By tying only 4 cells together in series and charging the pack at
less than 1C of the pack capacity a BMS is not a requirement and
conventional 12 volt chargers could be used on occasion to restore a
charge to the battery when completely run down. The battery is
designed to replace a conventional lead-acid starter battery in an
ICE (internal combustion engine) vehicle. It will deliver 900Amps for
a short time (30 second) or 270Amps continuously until drained (about
10 volts).

- short life is also a matter of perception, my biltema battery is 1.5 years old and is giving up... so if I get 4 years out of this one, while help relieve the water pump, maybe it is not that bad.

I guess someone will just have to test them.

BTW - good going with the diagnostic tool! Would be really exciting to see one!

[El rayo]

Here is another source. Optimum make packs from barrel shaped cells, 26 mm diameter and 650 mm long, to get different voltages and capacities. Haven't found the price for these, either. They have an "advantaged battery management system to protect each cell".
http://www.optimumchina.com/en/Products_po.html

[Ken]

Amusing to read the Chinese English , otherwise I am impressed with the other contributors in this thread. I wish my norwegian was as good

[El rayo]

I wish my norwegian was as good

Don't worry, Ken. Your Norwegian is god. We learn English from the 5th grade (age 12).

[elektrolux]

Anyone figured out a way to handle this?

Yes. Look at: http://elbil.no/forum/index.php?topic=1574.0

Basically its a matter of using a intelligent switch mode charger permanently hocked up to the 12V battery, and taking power from the 114V traction battery. ( make sure the switch mode charger is fully electrically isolated between in and output, and willing to work on DC current input)

We did a bench test of this simulating the 120mA constant draw from a Think 12V battery, and our Lidl charger held the 12V battery at 13V and abowe DC-DC activation voltage of 12,3V

Also, when you say you been kind to the new Biltema battery; does that include a full charge before use. In the car, and with 13,8-14,1 Volts charging voltage, it will newer fill up, thus newer reach full potential capasity.

[Betacar]

My first wish: (Because i realy need it)

As you say, even the ability to initialize waterfill
, currently my program just shows parameters. The service functions will take more time to implement.

My second wich: (Because it is realy fancy and practical :-)

... and maybe an sms when the charge is ready...

So, how far have you com?   

[BauDemo]

Thanks electrolux - I was following that thread with great interest - my local lidl has exactly that charger... I will try to pick one up this week.
Betacar and the rest - status update:
The interface hardwarewise is ready. I have almost (just got the last component) assembled 10 cables (2 are already booked). I have solved the usb issue and now the cable can be used with usb too.
I am fixing up bugs and making better interface for the program  - the initial version will contain only display of parameters. A later version will do the initial and maintenance charging with water fill.
I also made a small program for pocket pc. Works only with pocket pcs with host usb function (I tested it on fujitsu-siemens loox n560), and displays Amps, Volts, State of Charge, Battery temp. It has a huge bar graph for visualizing the current Amp draw, and provides logging and other capabilities.
Someone will be helping me out with testing of the program and the interface, and as soon as this test is satisfactory (=no bugs, and all works as expected), the cable and the programs will be available.
I apologize for the delay!

[eledille]

My default "plan" is to provide the program as shareware, the reading of parameters functions will be free of charge. The playing around with error codes and other "advanced" stuff may be for small shareware fee. I spent extensive amount of time and money in making this possible and although I made it for myself, it would be nice to recoup some of it. These are just a random thoughts – I may end up with a very different license and solution.
I haven't given much thought on open source - I do not feel that I need help developing the program - I make living writing software.
I however think I need help in figuring out what the program should do to make the life of a THINK owner easier.
I have already started on functions for calculating the battery pack internal resistance, few ideas for alarms when some parameters do not correspond...

Ilmar, if you have any personal experience with releasing software under open source, I would be happy to hear it...

If you are planning to make a product for sale, this still does not mean you cannot make money by making the source code available.

Can you please elaborate, what would this business model be?

You wouldn't primarily open source the software to get help, but to let others build cool stuff using the knowledge embedded in your source code. If you make the code available, others will probably do things with it that you didn't think of. That would benefit everyone, including you.

There are multiple business models for open source. Remember the nineties, when SunOS used to cost multiple thousands of dollars per license? Today, Solaris is free, and Sun lives happily selling hardware and consulting services. MySQL is free, but you can buy support. Wikipedia employs about 30 people and runs a server farm on donations alone - I know I would be willing to donate more if source code was available than I would be willing to pay for a license that I can basically only use the way you planned for me.

If I had your source code, I might port it to Linux, and I might write a Perl interface for it. Perhaps a Munin plugin? And I'd buy your connector, and donate a few hundred. I'm sure someone will beat me to it, though.