TDI mit zu kleiner Batterie: Probleme? | Posts 32+

How about a lithium-ion battery? Porsche offers it as an optional feature.
Saves over 10 kg compared to a conventional 60Ah battery.

However, it costs a small fortune of 2500 EUR.

http://www.elektroniknet.de/automotive/news/article/24607/1/Porsche_Li-Ion-Technik_fuer_Starterbatterie/

Bertil wrote:

ulf wrote: .... Intermediate conclusion: For approximately 6-7 kilograms of weight loss, I would do it again. Okay, let's get down to business. Do you think this procedure is feasible for everyone and everywhere (including, for example, parking under a streetlight at -25°C)?

If I have to answer directly: probably not.

That doesn't change the statement that I (under my conditions) would do it again based on the previous results .

Since yesterday, the Saxo has been put away for the season. Its seasonal registration expires at the end of the month, and I know that given my schedule for the next two weekends and the forecast for rainy weather, I won't be able to take it out again.

The installed 18 Ah scooter battery is supposed to deliver a cold-test current of 220 A. It should be about a year old by now. However, it hasn't been stressed with winter cold starts; instead, it spent the winter in the basement at a minimum temperature of 10 degrees Celsius and was charged approximately once a month using an intelligent charger from the Lidl Foundation. During occasional rides, it sometimes has to handle short distances and city traffic, but usually, there isn't a large energy demand due to things like headlights, heating fans, or similar equipment being turned on.

"I plugged the battery into the charger in the basement yesterday. Initially, it drew about 4.5 amps, then 0.5 amps after 1 hour, and this morning I disconnected the charger when it was below 0.1 amps. According to the program LED, it had switched to trickle charging. The device also has an automatic detection feature for car or motorcycle batteries. However, yesterday before storing it away, there were several short trips for washing and refueling. I think the battery will still be able to start the 1.6-liter gasoline engine strongly next year."

ulf wrote:

Okay, here's a brief summary at the end of the first winter for the mini-battery system. I didn't make it easy for her because I turn off the engine during longer red lights or when going downhill. In winter, the headlights and electric power steering draw significant amounts of current from the battery for several minutes, plus potentially the windshield wipers and the small amount of power needed for the ignition, ESP, and other systems. As a counterbalance, I would connect the Ibiza to my small charger, which is now voltage-regulated and temperature-compensated, every few days, and fully recharge the battery over several hours each time. Occasionally, the ABS warning light illuminates for about a minute after I restart the engine while driving. However, I use the start-stop extra button because turning the ignition key is too cumbersome, and also because the power steering only starts working after "ignition off" when the engine is running. Rapidly descending through tight curves with passive power steering feels like serious strength training due to the extremely heavy steering, and it reduces reaction time in sudden danger to almost zero. Therefore, my stop button only interrupts the signal to control unit (CU) via terminal 15. This means that all other functions remain active and register the voltage drop during startup without a previous boot cycle; or, in other words, the power steering continues to operate even with the engine off. Under the most extreme cold start conditions, the engine block likely cooled down to approximately -3°C (although, thanks to the garage attached to the house, which is slightly heated due to heat loss from the walls). Based on the starter motor speed, I never noticed any signs of the battery being overloaded.

Balance sheet after the second winter with the small 45Ah battery:
Basically, as mentioned above. While the starter sometimes seemed a bit sluggish when the engine was completely cold (perhaps also because I was anticipating the battery failing), the BUK always started on the first few cranks. There was never a feeling like "three more compression strokes without ignition, and then the battery will give up."

Preliminary conclusion remains the same: I would do it again for a weight reduction of approximately 6-7 kilograms.

Roger wrote:

ulf wrote: And what happens next? A button cell battery for the motorcycle? Kickstarter ?

Hi there,

"I'm laughing my head off, but no, I remember that from way back in my student days – the hand crank, at least on the R4 and the 2CV."

Ein weiterer etwas teurer aber deutlich leichterer Ansatz sind LiFePo4 Zellen z. B.
Capacity: 4200mAh
Voltage: 4S1P / 13.2v
Discharge: 30C continuous / 40C burst.

For my track bike, a battery like this easily lasts for 3 sessions of 30 minutes each and only powers the starter motor, engine electronics, and fuel pump. The alternator was removed to save weight, which results in over 20 kg less weight overall, representing more than a 10% reduction in the bike's weight.