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bigdaddyo811 · 02-01-2012, 06:11 AM

What happens if you let the battery drain right down to 0 miles?

I worry because even in Sport mode the battery seems to drain just a little.

SoCalGuy · 02-01-2012, 06:14 AM

You're then powered by the ICE... which limits the power to a peak of 260hp, so your 0-60mph times will likely be around the 8s mark rather than the 6s in true 'Sport' mode.

dennis · 02-01-2012, 06:45 AM

(02-01-2012 06:14 AM)SoCalGuy Wrote: You're then powered by the ICE... which limits the power to a peak of 260hp, so your 0-60mph times will likely be around the 8s mark rather than the 6s in true 'Sport' mode.

Yesterday I learned from one of the mechanics that the engine only runs at a few different RPM levels. They found that at 2400 rpm the generator was producing 97% of the current that it produced at 6000 rpm. This is one of the ways they reduced the noise from the ICE.

SoCalGuy · 02-01-2012, 06:59 AM

(02-01-2012 06:45 AM)dennis Wrote:
(02-01-2012 06:14 AM)SoCalGuy Wrote: You're then powered by the ICE... which limits the power to a peak of 260hp, so your 0-60mph times will likely be around the 8s mark rather than the 6s in true 'Sport' mode.

Yesterday I learned from one of the mechanics that the engine only runs at a few different RPM levels. They found that at 2400 rpm the generator was producing 97% of the current that it produced at 6000 rpm. This is one of the ways they reduced the noise from the ICE.

...and probably much more fuel efficient at that lower RPM...

**Fabulist** · 02-01-2012, 07:05 AM

(02-01-2012 06:11 AM)bigdaddyo811 Wrote: What happens if you let the battery drain right down to 0 miles?

I worry because even in Sport mode the battery seems to drain just a little.

Even at 0 Miles, the battery still has around 15% charge in it according to the battery SOC meter in the instrument cluster. I think the car "borrows" from that reserve for better performance and to give the ICE time to start up and come to speed, and the generator than pays it back when it is generating power so that the reserve stays constant. I don't think you ever want to see the battery SOC meter (as opposed to the "miles to go" meter) get close to zero.

-- Fab.

SoCalGuy · 02-01-2012, 08:00 AM

(02-01-2012 07:05 AM)Fabulist Wrote:
(02-01-2012 06:11 AM)bigdaddyo811 Wrote: What happens if you let the battery drain right down to 0 miles?

I worry because even in Sport mode the battery seems to drain just a little.

Even at 0 Miles, the battery still has around 15% charge in it according to the battery SOC meter in the instrument cluster. I think the car "borrows" from that reserve for better performance and to give the ICE time to start up and come to speed, and the generator than pays it back when it is generating power so that the reserve stays constant. I don't think you ever want to see the battery SOC meter (as opposed to the "miles to go" meter) get close to zero.

-- Fab.

I can't imagine that Fisker would allow you to have the battery deplete fully to zero - in fact, its odd that they would display its true state of charge. My recollection in the gas analog world is that when your fuel gauge reads "empty" it actually still has 1-2ish gallons on reserve or so... I would presume Fisker would be smart enough to do that in the battery analog too!

bigdaddyo811 · 02-01-2012, 09:00 AM

My dealer told me all the problems with stranded cars etc.. occurs if you let the miles go below 5m and told me not to do so.

I assume even if your battery (miles left) goes to zero, you should be able to drive the car around indefinitely in sport mode?

siliconkiwi · 02-01-2012, 09:28 AM

I drove around in Sport with the battery at 1 mile for about 20 miles, with no problems (touch wood)

**Fabulist** · (This post was last modified: 02-01-2012 09:33 AM by Fabulist.)

(02-01-2012 08:00 AM)SoCalGuy Wrote:
(02-01-2012 07:05 AM)Fabulist Wrote:
(02-01-2012 06:11 AM)bigdaddyo811 Wrote: What happens if you let the battery drain right down to 0 miles?

I worry because even in Sport mode the battery seems to drain just a little.

Even at 0 Miles, the battery still has around 15% charge in it according to the battery SOC meter in the instrument cluster. I think the car "borrows" from that reserve for better performance and to give the ICE time to start up and come to speed, and the generator than pays it back when it is generating power so that the reserve stays constant. I don't think you ever want to see the battery SOC meter (as opposed to the "miles to go" meter) get close to zero.

-- Fab.

I can't imagine that Fisker would allow you to have the battery deplete fully to zero - in fact, its odd that they would display its true state of charge. My recollection in the gas analog world is that when your fuel gauge reads "empty" it actually still has 1-2ish gallons on reserve or so... I would presume Fisker would be smart enough to do that in the battery analog too!

That's correct if you are draining the battery by driving the car. However, if the car has spent a lot of time turned off, for example, sitting on a ship for a few weeks, then sitting at the port for another couple of weeks and then spending two weeks on a transport, the battery charge my dissipate and the computer can't do anything about it because the car is turned off. Now if the car is not properly charged before you attempt to use it, you may be in for a world of hurt, as I briefly experienced when I picked up my car on Saturday. As long as you drive and/or charge the car regularly, there should be no problem.

-- Fab.

(02-01-2012 09:00 AM)bigdaddyo811 Wrote: My dealer told me all the problems with stranded cars etc.. occurs if you let the miles go below 5m and told me not to do so.

I assume even if your battery (miles left) goes to zero, you should be able to drive the car around indefinitely in sport mode?

(02-01-2012 09:28 AM)siliconkiwi Wrote: I drove around in Sport with the battery at 1 mile for about 20 miles, with no problems (touch wood)

I drove my car all the way down to 0 in Stealth mode for 25+ miles yesterday and nothing bad happened. The generator comes on when the battery gets low enough and the car keeps on going. I did not even have to switch to Sport mode. The car knew what to do.

-- Fab.

bigdaddyo811 · 02-01-2012, 09:36 AM

When I drive in SPORT, the battery slowly decreases. Doesnt that mean that if you drive around for a long time with the battery miles at 0 that you will run into problems as the battery will completely run out and the car will be dead?