inverters

[slowfen]

Hi

Mrs SF is getting an ebike so that she can keep up with me. For some of the time it will be used whilst off-grid caravaning, so its charging needs to be sorted. From what I can see the bosch chargers rating is for the output current ( ie the 4amp is 4A at 36V making 144 watts) As such this means at the mains side it would be 240v at 0.6 amps, making a 300watt inverter fine.

does tthis make sense?

Many thanks

 

[presta]

300W should be enough, but if you're tempted by anything smaller bear in mind the charger efficiency. I wouldn't go below 200W.

 

[CXRAndy]

That is fine, make sure it's got good overload and short circuit protection

 

[numbnuts]

View: https://youtu.be/8_2AlA_i8w4?si=WX8KwWWq46ZJhFCo

 

[sleuthey]

The charger voltage will probably be slightly above 36v and also both the inverter and charger will not be 100% efficient mainly due to heat/noise/fan movement. However I would say 300w gives you an adequate safety margin to cover the above.

 

[tom73]

Just make sure your leisure battery is up to it. Inverters take a lot of out of them and can easily fry one.
You thought about a battery pack like an EcoFlow? They have a built in inverter, and added benefit of being portable.

 

[Jameshow]

Do Bosch do a 12v ebike charger?

They do for power tools so the tech is there?

Much more efficient than stepping up to 240v and down to 36v??

 

[CXRAndy]

Do Bosch do a 12v ebike charger?

They do for power tools so the tech is there?

Much more efficient than stepping up to 240v and down to 36v??

The losses are extremely minimal. Using switch mode power supplies are far cheaper and significantly lighter in weight compared to using large copper wound transformers

 

[ebikeerwidnes]

Ebikeshop seem to have a 12V charger for Bosch
https://www.e-bikeshop.co.uk/blogs/info/bosch-ebike-12v-travel-battery-car-charger/

it seems to have Bosch written on it so I presume it is genuine so will work

 

[Emanresu]

Will she be maxing the miles on the battery? If you are only topping it up you can get to 80% charged quite easily. It's the last 20% that takes the time.

 

[slowfen]

@ Tom73 - Leisure battery should be upto it, 120amp/hr, does power mover when needed

@ ebikeerwidnes - I've seen 12v bosch chargers before, but currently do not seem to be in the UK/EU

@ Emanresu - unlikely charge will be maxed out, also would not be used every day

Many thanks for all the help/advice

​

 

[ebikeerwidnes]

Hmm - there seem to be 12V chargers available on ebay

but unless it was a proper branded Bosch system then I wouldn;t use it
especially on Bosch because of their rather over enthusiastic systems

but also because of safety and all that