What size inverter

[Silver-Fox]

My dearest Daughter has asked me what size inverter she needs to charge her electric bike battery.

It’s a 750w battery and I don’t know what to allow extra for the initial draw.

She will be buying a Renogy inverter off Amazon.

Thanks all

 

[pappajohn]

You need to know the chargers input wattage.
Whatever that is (on the charger label) then add at least 50%.....IE ..100w charger = 150w minimum inverter

 

[scotjimland]

My dearest Daughter has asked me what size inverter she needs to charge her electric bike battery.

It’s a 750w battery and I don’t know what to allow extra for the initial draw.

She will be buying a Renogy inverter off Amazon.

Thanks all

The mains Amps will be on the charger data label .. ask her for a photo of the label

..my e-bike battery is 1400wh .. and the charger draws 2A

2 A x 240v =. 480w

so a 500watt inverter would be adequate

she maybe better with a pure sine inverter rather that a quasi sine

 

[Silver-Fox]

Thanks for the quick replies.

I’ve already told her to get pure sine

I’ll ask about the charger

 

[Silver-Fox]

scotjimland

Picture as requested

Thanks

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[scotjimland]

scotjimland

Picture as requested

Thanks

no photo

 

[pappajohn]

2 A x 240v =. 480w

so a 500watt inverter would be adequate

Doubtful Jim.
You haven't taken into account inverter losses and start up surge.
480w may be 2AH at 240v but it's 40 AH from the 12v battery

 

[Silver-Fox]

no photo

 

[scotjimland]

Doubtful Jim.
You haven't taken into account inverter losses and start up surge.
480w may be 2AH at 240v but it's 40 AH from the 12v battery

yes John am aware waiting for photo for definitive calculation ..

 

[Silver-Fox]

yes John am aware waiting for photo for definitive calculation ..

Sorry about the photo

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[Silver-Fox]

Apparently her battery is 750wh

 

[pappajohn]

That's 18watts at 240v.
360watts at 12v.....30amps+ inverter losses from the battery for each hour on charge

 

[scotjimland]

View attachment 907167

the charger input is 1.65A at 240 = 380 w

500 w inverter is adequate ..

when charging the inverter will draw about 30A from the battery.. charging tine say 4 hours = 120AH ..

unless she has a big battery bank, need to charge while driving ..


I bought one like this for my van to do that job

500W - 12V Pure Sine Wave Sunshine Power Inverter

Sunshine Pure Sine Wave Inverters are suited for sensitive electronic equipment, allowing motors to run faster, quieter and cooler, preventing computer crashes, noises & glitches in monitors, TV, game consoles etc. Convert DC power from your battery into AC power enabling use of electrical...

www.sunshinesolar.co.uk

 

[pappajohn]

Apparently her battery is 750wh

Other than the time taken to charge the battery capacity is immaterial.

 

[pappajohn]

My bad Jim.
Confusing myself.
I was taking what you said your battery takes to be the answer to the question

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[TrudeandDall]

View attachment 907167

This is the same charger as I have for our 750w Bosch batteries. I charge two of them simultaneously from a 600 watt PSW inverter and it never has a problem. The two draw around 16amps together, so a single one should be around 8amps. 500w will be more than adequate for your daughter
What you must consider is the lesiure battery capacity as she will be pulling 8 amps for up to three hours for a 60% depleted bike battery. And how she can recharge the lesiure battery?

 

[Silver-Fox]

Thanks for your replies.

She has two 100ah wet batteries.

1 100w solar panel.

I’m thinking if she gets a 1000w inverter she could run a small kettle of it now and again for a coffee etc.

She will charge her lap too off it as well so she says.
Personally I’d get a 12v charger for the laptop as I bought for my old Mac.

Thanks again

 

[Silver-Fox]

Just a quick revival.

Any thoughts on a 1000w inverter so it could be used for a small kettle?

Is two 110ah wet batteries man enough for the job required?

Thanks

 

[MisterB]

Why not fit as big an inverter as she can afford/fit in the space available. That way if she ever changes batteries etc she won't need to splash out on a bigger inverter? I would be looking at he Renogy 2000W as a minimum.

As regards the batteries themselves, lots of Funsters manage with similar batteries until it's time to replace them, they just make sure they treat them kindly to prolong their life.

 

[fred_jb]

Just a quick revival.

Any thoughts on a 1000w inverter so it could be used for a small kettle?

Is two 110ah wet batteries man enough for the job required?

Thanks

We have a Renogy 1000W inverter and this is great for running our 850W travel kettle and is so much faster than boiling a kettle on gas. Also works for my wife's travel hairdryer which I think is about 900W on its highest setting. We have two 100 Ah AGM batteries and they seem to be man enough for the job. It just sparks the solar controller from float mode into full MPPT charging mode!

With our setup I wouldn't go for a more powerful inverter. It would be nice to be able to run the 1500W air fryer but I think a 2000W inverter running that would take too much out of the batteries, so can only use the it on EHU. Maybe if I convert to lithium at some point, but the AGMs are only a year old having come fitted to our new van!