Author Topic: amps, volts `n watts  (Read 1166 times)

amps, volts `n watts
« on: 24 May, 2022, 08:48:21 pm »
had to get a recumbent trike a while back
The relief was instantaneous. No more balance or direction problems
As is the way with these things one gets pi**ed off being overtaken by joggers
 I have now fitted a motor and the bits and bobs to  feel the wind in my teeth.
Right, down to the leccky bit

Wheel motor is 48v 500w with a 18ah battery.
Range is pretty good, 60+ miles and still some life left, not a lot, but I like it !!
used mainly on lowest setting except at R.A.B`s and such like

Q: will a 48v battery with higher wattage and ah cause bother or is it ok as long as it is 48v ?
hope that makes sense
Thanks for any useful replies in advance

Re: amps, volts `n watts
« Reply #1 on: 24 May, 2022, 08:57:38 pm »
I would think it's the motor that's rated at 500W. That will also be rated for 48V.

Any replacement battery must therefore be 48V, but the energy stored is the AH figure, so get a battery with as big an AH figure as you want.

Rust never sleeps

Re: amps, volts `n watts
« Reply #2 on: 24 May, 2022, 10:15:51 pm »
thanks Hatler
Just the thing I was looking for
Bit of a sod when even simple things evade the grey matter

Mr Larrington

  • A bit ov a lyv wyr by slof standirds
  • Custard Wallah
    • Mr Larrington's Automatic Diary
Re: amps, volts `n watts
« Reply #3 on: 24 May, 2022, 11:11:21 pm »
Think of it as being analogous to fitting a bigger petril tank.
External Transparent Wall Inspection Operative & Mayor of Mortagne-au-Perche
Satisfying the Bloodlust of the Masses in Peacetime

Kim

  • Timelord
    • Fediverse
Re: amps, volts `n watts
« Reply #4 on: 24 May, 2022, 11:18:02 pm »
Think of it as being analogous to fitting a bigger petril tank.

But one that's the same height, so the fuel is still reaching the motor at the same pressure...

Mr Larrington

  • A bit ov a lyv wyr by slof standirds
  • Custard Wallah
    • Mr Larrington's Automatic Diary
Re: ants, voles `n watts
« Reply #5 on: 24 May, 2022, 11:56:24 pm »
Lengthy monologue about failed Saab fuel pump goes here ==>
External Transparent Wall Inspection Operative & Mayor of Mortagne-au-Perche
Satisfying the Bloodlust of the Masses in Peacetime

Re: amps, volts `n watts
« Reply #6 on: 11 July, 2022, 08:44:21 am »
Many people get confused because rather than amp hours which they're used to for single cells, ebike battery capacity is often advertised in watt hours which takes into account the different voltages used.

Kim

  • Timelord
    • Fediverse
Re: amps, volts `n watts
« Reply #7 on: 11 July, 2022, 10:15:12 am »
I'd say that watt-hours is usually the more sensible unit for answering "how much energy does this battery hold".  Amp-hours is like gear inches, in that it's convenient for some calculations, but doesn't tell the whole story.

USB power banks are a main offender: They sell them based on the amp-hour capacity of the 3.7V cell, rather than at the 5V output.  Makes for bigger, but less useful numbers.  At least Watt-hours would be unambiguous.

T42

  • Apprentice geezer
Re: amps, volts `n watts
« Reply #8 on: 11 July, 2022, 10:33:05 am »
Think of it as being analogous to fitting a bigger petril tank.

But one that's the same height, so the fuel is still reaching the motor at the same pressure...

Maybe need to fit a supplementary vole-pump.
I've dusted off all those old bottles and set them up straight

Re: amps, volts `n watts
« Reply #9 on: 11 July, 2022, 10:46:19 am »
Lengthy monologue about failed Saab fuel pump goes here ==>
Or even the requirement to carry a mallet, and have the spindliness required to be able to reach under the car and above the axle to give the electric fuel pump of a Healey Sprite a sufficiently sized whack to bring some order back to its sad life.
Rust never sleeps

Mr Larrington

  • A bit ov a lyv wyr by slof standirds
  • Custard Wallah
    • Mr Larrington's Automatic Diary
Re: amps, volts `n watts
« Reply #10 on: 11 July, 2022, 11:01:34 am »
This was folding down the back seats and pummelling the boot floor with r skinny fists to persuade enough petril into the engine to get within a day's march of a phone box.  Early 1970s, when mobile telephony was the preserve of Bond James Bond villains and Richard Nixon [“Same thing!” – Ed.]
External Transparent Wall Inspection Operative & Mayor of Mortagne-au-Perche
Satisfying the Bloodlust of the Masses in Peacetime