5 votes

Could a Mercedes sedan powered by 9,648 AA batteries reach 52 mph?

If we ignore almost all the details, assume everything is totally lossless, and just look at whether there's enough energy in the batteries to accelerate the car to the required speed, the answer is ...
Hearth's user avatar
  • 30.4k
3 votes

Less than minimum charge voltage for NiMH battery and extra parts in a "simple" circuit

Update & Supplement #2: I found other information here in the EESE site and in Linsen’s great “Handbook of Batteries” that supports my original answer, but I felt the need to clarify and update ...
EJE's user avatar
  • 1,479
2 votes

Replacing Li-ion battery in a game controller with a supercapacitor

If you wanted wireless mode (battery equivalent) you would need to compare the relative energy capacities of the existing cell and typical supercapacitors. Let's guess that the Li-ion battery has a ...
colintd's user avatar
  • 6,216
2 votes

Can you charge a 12vdc car battery with a 18 volt tool battery charger?

No. The charger won't know when to stop properly or how to monitor the cells; it will likely refuse to charge entirely. Furthermore, batteries cannot change their rated voltage by charging at a higher ...
vir's user avatar
  • 16.3k
2 votes

How does this lithium-ion battery charger work?

That Q1 is an NPN transistor. And that circuit should not be used to charge lithium batteries. It will overcharge them, overcharging will damages the batteries, and damaged batteries might explode or ...
Justme's user avatar
  • 138k
2 votes

Why are capacitors more dangerous than batteries?

Capacitors have much higher power density than batteries, because the latter have comparatively higher internal resistance. If that wasn't so, chances are capacitors would be obsolete in many ...
tobalt's user avatar
  • 19.7k
1 vote

Why are capacitors more dangerous than batteries?

I think that the "capacitors are dangerous" fear largely comes from vacuum tube days, where most circuits used 200 - 300 volts, and capacitors could hold that voltage for some time after the ...
Peter Bennett's user avatar
1 vote

Why are capacitors more dangerous than batteries?

Capacitors are not necessarily more dangerous than batteries. It all depends on the specific capacitor and battery, and the voltages present on each. Capacitors have internal resistance called ESR, ...
John D's user avatar
  • 23.6k
1 vote

In a 3-cell series battery, is it normal for 'middle' cells to have lower voltage vs. outer cells when removed and measured individually?

The reason for the mismatch may be heat as Jen suggests, since the run time and current is long enough to cause the cells to heat. However I don't think that's causing the short pack life- maybe the ...
Spehro Pefhany's user avatar

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