What inverter do I need

A 300watt PSW inverter would be able to cope no problem as colinm said.

As for ohms law it has always worked for me. The max surge current from the charger would occur if the inverter has a 110vac output and would be less than 250watts.
 
RoadTrek Boy said:
As for ohms law it has always worked for me.
Click to expand...

Sorry to keep on about this but one of us is wrong and is publishing information that could cause another member to have problems.

For me Ohms law is that the voltage across a conductor is directly proportional to the current flowing through it, provided all physical conditions and temperatures remain constant.
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Ohm’s Law - Statement, Formula, Solved Examples, Verification, FAQs

Ohm’s law states that the current flowing through a conductor is directly proportional to the potential difference applied across its ends. Learn definition, and formula at BYJU'S.
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This means that reducing the voltage reduces the current.

You seem to be saying that reducing the voltage increases the current which is the exact opposite.

Could you please tell me what you understand by Ohm's law and provide a source

Many thanks









RoadTrek Boy said:
A 300watt PSW inverter would be able to cope no problem as colinm said.

As for ohms law it has always worked for me. The max surge current from the charger would occur if the inverter has a 110vac output and would be less than 250watts.
Click to expand...
 
r4dent said:
With respect I think it is you that is wrong.

There is no mention of watts on the charger plate just volts (100 - 240) and amps (max 25).
A watt is a measurement of power.
Devices do not have a fixed wattage, they have a fixed resistance which is measured in Ohms.

The relation ship between voltage, current, resistance and power is stated in two established laws of physics.
a) Ohm's law.
"The current that flows through conductors is directly proportional to the voltage applied to it.
In formula terms V = IR where V = Potential difference (volts); I = Current (amps); R = resistance (ohms)

In other words if the voltage is reduced the current will also reduce.
An example is leaving a vehicle headlights on without the engine running.
After a while the battery voltage is reduced, when this happens the current is also reduced.

b) Electrical Power law
The electric power is given by multiplying the potential difference by the current.
In formula terms P = VI where V = potential difference (volts); I = electrical current (amps); P =power (watts)

In other words if the voltage is reduced the power will also reduce.
As the voltage of the car battery decreases so will the brightness of the bulbs and this is what happens in the real world.

Now returning to the Charger.
The higher the input voltage the higher the current (as per Ohms Law) so the 2.5 amp will be when the input voltage is 240v.
Using the Electrical Power law, the power is 2.5 a x 240v = 600w

If the input voltage is reduced to 100v
The current will be reduced (Ohms law) the power produced (Electrical Power law) will be reduced and thus the scooter battery will take longer to charge.
This is illustrated by people using an air dryer in countries using 110v mains, when the operation takes longer.
Click to expand...
Sorry but Road trek boy and Colinm have got this one right.
Your maths is correct but it only applies to purely resistive loads like the hair dryer in your example. A charger is not a fixed resistance. If it were the output voltage would always be the same as it's input voltage and this cant be allowed because the output voltage must be stable at 54.6V in this case.
The battery charger in question will work on the SMPS (switch mode power supply) principle and SMPSs have the ability to provide the same output voltage (54.6V) at the same output current (2A) from a wide range of input mains voltages (in this case 100V-240V) Automatically without having to adjust to the differing mains levels with around 90% efficiency.
The output voltage is fixed at 54.6V (Crucial ) as is it's maximum current capability (2A) so 110W output capacity so ohms law dictates that the input current must go down as the input voltage goes up.
 
I was linked to a 4amp charger for mine but didn't buy one, there might be similar for this one as well.
 
Polar Bear said:
Why not buy a spare 'chair battery' as a backup if you need to use the chair on a second day?
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A lot of scooters have more than one battery, mine has two but a lot cheaper than Pudsey li-on setup.

Without digging out my charger I can’t be certain but I seem to think it’s the same as the op’s and mine ran ok using a 300w inverter. I also have a 12v dc power brick to charge mine but this takes significantly longer than the 240V charger. Mine isn’t a fast charger, can take up to ten hours to fully charge my 2x17ah battery’s. Have to be careful if it isn’t good solar weather. The escooter is much better for power and charging than the mobility scooter but of course I have to watch where I use it as illegal in uk
 
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