Super capacitors to replace 12V battery ?

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Llecentaur

Well-known member
Joined
Dec 27, 2012
Messages
240
Would you think that this module will deliver enough power for the i, including the capacity of running the pump of a Webasto parking heater ?

http://www.ebay.com/itm/111373572497

Also wondering if it would need a casing to protect it from water projection if replacing the 12 V battery ?

Besides longevity and lower weight, I am thinking that such small sized battery would allow installing the Webasto directly in the front of the car where the lead battery sits, so easily keeping the electric heater as well.
 
It can definitely supply the amps to start the i-MiEV (starting power is very low compared to ICE), but I'd be careful not to leave anything on if the i-MiEV isn't in READY or charging.
 
This is really interesting.

The question would be how long is your car sitting while not charging. If this pack of Caps can cover that time then I would guess it should work fine.

The other issue would be any 12v loads turned on without the car in the ready mode. I'm sure that you could drain the caps downtown nothing if you pulled the high beam lever for too long with the car off.

Not the you would do that but the buffer would be less.

I read somewhere in this forum that if the 12 v system goes dead then you get a warning light on the dash that needs to be cleared at the dealer. You would really want to avoid that.

But it's still a really interesting idea. Especially if it enables the install of the water heater.

Don....
 
The specified ultracapacitor has capacity of 58.3 Farads at 16.2 V max. This comes to 4.25 Wh capacity (provided I have figured the calculation right), which is much lower vs. estimated 400 Wh capacity of the OEM 12V battery.
Recently, I have measured Amps coming from the 12V battery under various conditions. When everything is off, the base current is 20-30 mA. This serves the radio receiver so that you can open the car with the remote. So, when considering 12V and average 25 mA, those 4.25 Wh should be consumed in about 14 hours. This is a bit unsafe margin.
Then, before you engage the DC-DC convertor, you need to open the door and turn on the electronics:
- open the door ............ 410-420 mA (I have LED dome lights!) ...... 51 minutes on 4.25 Wh
- ignition key in ON position ...... 3.30 - 3.33 A (stereo OFF) ...... 6.4 minutes on 4.25 Wh

Stan
 
I actually tried the other way round. I did connect a 10 Ah lead acid and a 2.3 Ah NiMH parallel at the lighter socket. I did get more range.

How is that?

Somebody with canIon suggests it might be 7% more comparing with and without the aux battery. We have too view numbers to say anything yet.

What I observed is - I burnt a fuse, 6.3 amps in my lighter socket connector. 10 amps seems to be fine.

Rumors from Mitsu say 8 Ah is enough but Red Tape demands more so the lights can run for some time. My battery is 27 Ah.

Our 12 volt system runs from the DC-DC (80 amps) not from the 12 volt battery. The battery is connected via 30 amps fuses to the two fuse boxes, like any other consumer.

My hamradio 14,6 volt power supply unit greets my batteries with about 1 amp when I bring the pack back home.

More to come
Cheers
Peter and Karin
 
I looked into the SuperCap idea to replace the 12V battery. Much smaller size and lighter weight, both benefits are good. I saw an idea on YouTube where they paired the supercaps with a small lithium ion battery to make a hybrid battery. The guy shows starting his car at the airport after leaving it for a week in the bitter cold and the car started - this was for a gasser not an EV. That idea may have more merit and little bit more room for safety. An idea I'm toying with but haven't pulled the trigger on yet. I'm currently experimenting with taking an android tablet and using that for my car stereo!

peterdambier - that is an interesting experiment. I wonder if that would be an easy solution to extend the range a bit. I could have used that in June when I ran the car completely flat! I went beyond turtle into the the RED BATTERY ZONE! Ugh, that was an ugly EV day. The car died about 8 kilometers from home, I was so close. It died at an intersection and somebody helped push the car out of the road. I found an outlet nearby and tapped into that for an hour. Almost made it home before it died again. Ugh! It got uglier when I tried to tow it myself (couldn't find anyone to help me). I won't continue as the story gets worse. But, hey everything is good now.
 
MLucas said:
I saw an idea on YouTube where they paired the supercaps with a small lithium ion battery to make a hybrid battery.
Combine that with a solar panel somewhere on the car, and you shouldn't have to worry about the 12 volt system going dead again. :cool:
 
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