Gewichts-Tuning durch Ultracaps statt Bleiakku? | Posts 16+

Also, more full-load phases are needed during acceleration, which increases the overall efficiency.
A copywriter seems to have gone missing and ended up with you.

No, that's not really what I want to be either.

I see it the same way as Gremlin. I don't like giving up comfort in a car. It's especially nice when you have to drive longer distances. Shorter distances are no problem; I also enjoy driving our small car (a FIAT Punto 1.2 8V, 60 hp). After the firmware update from FIAT, it's surprisingly fast (but only up to 5,000 rpm), and it has no extra features beyond the standard ones, with a curb weight of around 800-900 kg.

@SeatArosa1.7SDI

'That's not a problem for me. If our new one needs less or the same amount of fuel as our old one did with 300 kg more weight, then I'm fine with that.'

Best regards, WarLord.

SeatArosa1.7SDI wrote:

I believe capacitors are actually very suitable for the starting process, even considering their discharge curve. This is because the power demand of the starting process decreases as the capacitor voltage decreases, resulting in a smoother and faster start. Trigger event: Second 0: The sprocket accelerates. . .

Hmm, you could see it that way, but I wouldn't be surprised if things don't quite work out as planned.

At least in my experience, projects like these always have various hidden problems, which ultimately lead to a spectacular failure.
For example, the starter motor will not make two engine revolutions at a constant speed, but will slow down due to the decreasing Uc voltage.

But go ahead and try it, and let me know what happened.

It's already been tried (see the link at the top). It's just a matter of finances and time. Unfortunately, there are no ready-made ultracapacitor + buffer battery modules yet that are in the form factor of a VAG-compatible starter battery.

That leaves a lot of manual work to be done. And it requires an investment of 350 euros in development costs.

In MAN test buses, ultracapacitors are even already being used for brake energy storage (!). They are particularly suitable in combination with fuel cell drives, but also with diesel-electric drives. You can find an animation of how they work here: www.ultracapbus.de

hi,
With the current state of the art, it is possible to draw 150A from a NiMH cell (3300mAh, manufacturer GP) for 10 to 20 seconds. After that, it must be switched off, otherwise the temperature will become too high. The cell is not completely discharged yet, but it needs a rest period.
At the same time, the voltage drops to approximately 0.7 to 0.8V.
Therefore, a charging circuit would be necessary. This is because the charging voltage can reach up to 1.8V during fast charging.
To be on the safe side, you would need to arrange 12 cells in a row.
That would result in a maximum charging voltage of just under 22V.
The charging electronics would need to make the adjustment.
The cell weighs approximately 64g, so the pack of 12 cells weighs just under 800g.

At 150A, it might even be possible to do without ultracapacitors.
greetings

Hmm, but without ultracapacitors, the lifespan of the cells would certainly be very limited. Such a sudden discharge definitely means high chemical wear and tear due to localized heat generation.

Ultracaps funzen physikalisch, Energie wird durchs elektrische Feld gespeichert. Minimal wear.

To charge the 10 NiMH cells: How about automatically connecting them in parallel in two groups of 5 (= 6V battery) while the engine is running? This would allow you to power existing 6V charging electronics with a 14V input voltage, without needing a DC-DC converter. It doesn't need to be a fast charger, but rather a battery-friendly charger with peak-delta-U cutoff.

Best regards,

Hi there,
I completely forgot about it yesterday.
NiMH batteries are not suitable for this task because it is problematic to only discharge a portion of their capacity and then fully recharge them.
While there are indeed NiCd and NiMH batteries designed for continuous use, they are not nearly as robust in terms of high current capacity.

but the solution is Lithium Ion .
Li-ion batteries behave similarly to lead-acid batteries.
The full charge voltage is a constant voltage, similar to that of lead-acid batteries.
Unfortunately, Li-ion batteries are not particularly easy to maintain.
This means that the charging electronics must absolutely monitor each individual battery in the series connection.
The latest high-current cells can only handle a maximum of 12C continuously and 20C for 10 seconds.
Capacity: 1100mAh. Weight: 41g.
The next problem:
Normal voltage: 3.7V. Charging cutoff voltage: 4.2V.
Three cells would be 11.1 volts (12.6V), which is actually too low.
4 cells, 14.2 (16. - actually, that's too much.
'There must be some immigrants coming in.'

The capacity, at 1100mAh, is also not satisfactory.
You can easily connect Li-ion batteries in parallel.
'So, there need to be at least three parallel connections to ensure a continuous current of at least 36 amps.'
It would be better to have 5 or 6 of them running in parallel.

Considering all of that, we've forgotten that we still need to factor in the cost of the spark plugs.

One of these lithium-ion cells costs almost 10 euros.
That would be approximately 160 euros, considering a 4x4 cell configuration.

but the simplest, safest, and probably cheapest solution would be to...
to use a high-current lead-acid battery from a UPS.
It would only require a very small charging circuit.
I'd say around 10Ah. It's true that they're not nearly as light as Li-ion batteries, weighing about 4kg, but they are cheaper and simpler.
greetings