What inverter do I need

[Kontiki]

I am looking at buying a power bank to use mainly for charging my mobility scooter. I thought about getting solar panel & inverter but thought a power bank would be more useful, also the leisure battery isn't very accessible . The specs of charger are Input A/C 100- 240V 2.5A max
Output 54.6V 2A.
What size would the inverter need to be?

 

[Glass man]

I haven't published this as it will get a lot of criticism by the ignition is best brigade.
Happy travelling

 

[r4dent]

Before you spend any money I think that you should consult a professional. There are too many variables to give a straightforward answer
(e,g type of scooter/ type & capacity of battery / usage / size of solar/ ti,,e of year and location of the MoHo)

You are proposing to convert the (say) 14v of your solar to 12v stored in the vehicle battery; then converting the 12v to 230v using an inverter; then converting the 230 v to (say) 14v using the scooter charger to charge the 60v scooter battery

To give you a simple idea
Whatt size inverter will run my charger?
You need to know the watts required by the charger. Volts * amps = watts so 240v * 2.5a = 600 watts
Inverter need a decent safety margin so I would go for at least 1200 w inverter.

How much current from the 12v battery is required to proved the 600 w required by the charger?
Volts * amps = watts can be rearranged to amps = watts / volts. So current = 600w / 12v = 50 amps. So your wiring needs to be thick enough for this.

Only 50% of a battery's nominal capacity is usable.
Which means a 100ah leisure battery will be flat after an hour.

I don't know how much power the scooter uses when you drive it but I suspect it is more than most solar system will provide (especially in UK).

My belief is that what you are proposing is not practical and that you will end up charging the scooter on EHU and only spending one night off grid before using another site to recharge. The other alternative is a 230v generator, but you will need to do the sums for that as well.

 

[Kontiki]

To clarify, I'm not think of using the leisure battery at all for this. I am looking at the Jackery type of power bank possibly with their own solar panel to charge. As we won't be doing long trips probably get away without charging while we're away.

 

[Robmac]

To clarify, I'm not think of using the leisure battery at all for this. I am looking at the Jackery type of power bank possibly with their own solar panel to charge. As we won't be doing long trips probably get away without charging while we're away.

Not sure why you need an inverter?

Doesn't the Jackery have 240v output and standard 3 pin sockets?

 

[Nabsim]

The power banks have an inverter built into them, you just need a big enough battery in the power bank that will charge your scooter and that you can top up in time if you need to

 

[Kontiki]

This is a pic showing my scooter charger. We aren't considering long trips so charging the power bank will mainly be done before leaving home.

 

[Kontiki]

I know the power banks have a built in inverter but depending on which we get the inverters are different power ratings. I don't want to waste money getting one that inverter is much more than we need, likewise it has to be large enough.

 

[Nabsim]

That looks similar to my scooter and I used to plug that into a 300W MSW Bestek inverter. Mine was a slow charger though so took a long time to charge up

 

[trevskoda]

Always go for an inverter output about 1 and a half times your requirement, you may require a bank with a pure sine wave output to power your electronic charger.

 

[r4dent]

I know the power banks have a built in inverter but depending on which we get the inverters are different power ratings. I don't want to waste money getting one that inverter is much more than we need, likewise it has to be large enough.

The same applies as my previous post.
The charger plate shows 230v & 2.5a (600w.)
The inverter (built in or external) needs to at least 600w and preferably 1200w.

Therefore, in my opinion, in the Jackery range only the 1000 will suffice and will not need a separate inverter.

N.B. the Jckery will be flat after 2-3 hours use.
Divide the power bank capacity(1000wh) by and the result by the power of the scooter (w) to calculate the number of hours of driving you will get.
e.g. if your scooter is 500 w you will get a couple of hours use of the scooter.

It is worth pointing out that, when on EHU, you will be able to charge the Jackery and the scooter (using the existing charger) simultaneously on a site supplying 10 or 16a.

I am very skeptical on their quoted 7.5 hr with 200w of solar. I suspect this is for Spain in August and a more realistic time in the UK winter would be measured in days.

Again,I strongly recommend profession advice before spending money

 

[1 Cup]

Fast charge to 80% if lithium. could use a b2b 30 + amp for that in van.
Power banks are heavy in weight and price at 2000w.
As every location uses differnt amounts to get to shops on cart ! I would go bigger on battery plus fast charger ?

 

[witzend]

To clarify, I'm not think of using the leisure battery at all for this. I am looking at the Jackery type of power bank possibly with their own solar panel to charge. As we won't be doing long trips probably get away without charging while we're away.

If you have a solar panel to charge the Jackery with it will be safer fixed to the roof where its a lot less likely to be stolen. A normal solar panel will charge a Jackery just as well as one of theirs's an is much cheaper to buy. Jackerys also have a charging lead to enable it to be charged while driving.
All this is working for me the link I've attached is for ebike batterys but should help with a mobility scooter battery as well

What Size Inverter To Charge E-Bike Battery? [With Size Chart]

If you are looking for the right inverter size to charge your bike, then give this guide a read to know everything you need

bikegrade.com

 

[Pudsey Bear]

That looks similar to my scooter and I used to plug that into a 300W MSW Bestek inverter. Mine was a slow charger though so took a long time to charge up

Same route I took, it was just taking too long though.

 

[RoadTrek Boy]

The same applies as my previous post.
The charger plate shows 230v & 2.5a (600w.)
The inverter (built in or external) needs to at least 600w and preferably 1200w.

This is a pic showing my scooter charger. We aren't considering long trips so charging the power bank will mainly be done before leaving home.



View attachment 118128

r4dent, I'm afraid you are incorrect, the charger plate shows a max of approx 250watts max, not 600watts as stated by you.
The 2.5a max would apply at 100vac input.. Hope this helps..

 

[r4dent]

r4dent, I'm afraid you are incorrect, the charger plate shows a max of approx 250watts max, not 600watts as stated by you.
The 2.5a max would apply at 100vac input.. Hope this helps..

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.

 

[Pudsey Bear]

My brain has just melted.

 

[RoadTrek Boy]

The output of the charger is 54.6vdc at 2A which = 109.2watts. The electronics converts the AC input voltage range of 100 to 240ac down to this, the highest current draw from the AC input will be at 100vac. The 2.5A max is allowing for surge current at switch on.
When the Battery charges the current drawn will taper off it depends how good the chargers BMS is..

 

[colinm]

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.

I think you will find you are wrong, the amps will be at 100v, at 230v the amps will be less, I've measured this on several chargers in the past.
I've posted this before, the best indication of power required is 'output + a little', so 109.2+, in which case 150w will be enough, but 300w is a common low powered invertor and be well up to job.

 

[r4dent]

The output of the charger is 54.6vdc at 2A which = 109.2watts

True.
The inverter needs to support the input power for the charger not the output power.
The input power will always be greater than the output power.
Some input power will be "lost" as heat / sound. No charger is 100% efficient
The only time output exceeds input is nuclear, where the output power is derived from the conversion of matter to energy (e=mc^2 and all that)

the highest current draw from the AC input will be at 100vac.

So Ohm got it wrong when he said when the voltage goes down so does the current.
Can you confirm that you are hypothesizing that when the voltage goes down the current goes up and the power remains constant?
How do explain the dimming of the headlights on my hypothetical car?
Scientific method does not support your hypothesis.

The 2.5A max is allowing for surge current at switch on.
When the Battery charges the current drawn will taper off it depends how good the chargers BMS is..

Yes, but any inverter needs to deal with the surge.
I believe this means that the inverter should be be capable of providing 600w.

The OPs question "was what size inverter is required?"
My answer is 1200w, because this is the smallest commonly available size over 600w. A 500w may be up to it, but I would not recommend this option.
What (or should I say what watt) is your answer?