Why F-1 cars use lead acid batteries?

[Ciro Pabón]

I do not know if this is an old question, but...

Why F-1 cars use lead acid batteries? There are batteries with a better energy/weight relationship. You know, they shave a kilo here and a gram there. This kind of batteries were the ones on Elvis's Cadillac, I would presume.

Then, why lead acid in R106? http://www.f1technical.net/f1db/cars/898

[jezzwa]

Well i think thats the Lead Acid batteries are still some of the most effecient batteries humans have made, and despite the fact they are heavy they can charge and dischrage very effeciently.

The efficiency of lead-acid cells at 85%-95% is much higher than Nickel-Cadmium at 65%, Alkaline at 60%

[ackzsel]

How about lithium-ion? Isn't Lithium-Ion capable of fast charging and re charging? The weight / charge ratio is in any case far better than NiCd or lead.

[Steven]

and how about NiMH ?
Well of course, it that can put the battery low to the ground there's no real weight issue as they are driving with lots of ballast already.

[Tom]

Slightly off topic but on the same note, if the BARs were so underwait, couldn't they have fitted a starter motor. They are what, about 4kilos max, then if the driver stalls on the grid, he can just push a button and rejoin the pack?

I know that there will be an obviouse reason but I can't find it.

[ackzsel]

Slightly off topic but on the same note, if the BARs were so underwait, couldn't they have fitted a starter motor. They are what, about 4kilos max, then if the driver stalls on the grid, he can just push a button and rejoin the pack?

I know that there will be an obviouse reason but I can't find it.

well, I guess that those 4 kilos are added at a place you don't want to. A starter motor also takes room and must be fitted a at a certain position. The starter motor must be fitted somewhere near the crankshaft to drive it. The crankshaft is mounted as low as posible and so are all of the heavy bulky parts. The design of the car must be altered a lot before you could fit a starter motor in a F1 car. Ofcourse this results in a lot of other problems.

So, I guess a starter motor is a nice idea but very complicated to realize.

[Apex]

Because then they would not have had a weight advantage... Its not as if BAR designed a super light car and were thinking what can we add to make it weigh more. If an F1 car is more than 500kg with out balast I would be surprised.

Putting a starter motor in is not that difficult if you got a caddy engine bay! There is no need to carry a starter anyway.

[ginsu]

A starter motor would require a MUCH larger battery to enable efficient cranking of the motor. Also, in order for it to be reliable you would need a bigger alternator to charge the battery. All of this is more weight and space where you don't want it, so I can understand why they don't do it, even though it'd help in a stall situation.

Technically, you should not be able to stall an F1 car due to anti-stall electronics. But somehow they manage.

[jezzwa]

Another reason why Lead-Acid batteries are used, is because they can still operate efficiently in higher temperatures, where are many other batteries lose efficiency exponentially as tempearature increases.

and how about NiMH ?

they don't use nickle metalhydride because they need to be completely discharged and then recharged for optimum performance.

[salilp]

One good reason for lead acid batteries is their high power to weight ratio.
Lithium ion batteries may have higher engery to weight ratio, but the problem lies in the amount out current you can draw from the batteries. Lead acid are useful in this aspect as you can draw excess of 10 amp of current at 12v, thus you can get more than 120 watt power from lead acid battery.

I'm not sure if this is entirely correct but any car will require high current for spark plugs, so lead acid is ideal choice.

[ackzsel]

I'm not sure if this is entirely correct but any car will require high current for spark plugs, so lead acid is ideal choice.

Yes, you are correct. Lead acid can deliver even higher current (like 900 A for a very short period), but so can NiCd. I think that the "memory effect" and temperature dependency are the most important factors...