A review of PedalCell, an impressive new rim dynamo

[raybo]

I just finished testing of the PedalCell, a new rim dynamo that is designed to charge USB devices while you ride. I was impressed by how much charge it delivered. If you tour with USB-chargeable devices, this dynamo will keep them in electricity without requiring you to plug them into wall outlets.

Here is a quick summary: Every time I rode with the PedalCell, my iPhone ended up with more power at the end of the ride than when I started, no matter what apps I ran on it or how long I rode. My estimate is that it added 20% charge to my new iPhone 12 per hour of riding.

I written up my findings in a detailed review of the device for those who want more information, including photos and numbers.

 

[IaninSheffield]

Excellent, thoroughly detailed review. Thanks.
If you've ever used one, do you have a sense of how the PedalCell compares with a hub dynamo in terms of performance? (I appreciate that the two different devices will have their own pros and cons depending on their different use cases) Thanks.

 

[Ming the Merciless]

I used to charge from SON hub Dynamo . Used to take 3 hours to charge my Sansung Galaxy from flat. But can’t remember what battery capacity that phone was.

 

[mjr]

I used to charge from SON hub Dynamo . Used to take 3 hours to charge my Sansung Galaxy from flat. But can’t remember what battery capacity that phone was.

Can you remember which of the 57 varieties of Galaxy it was, even?

But anyway, most hub dynamos are 6V 3W, so divide the Wh of the phone battery by 3, ignore the difference between 6V and USB's 5V and round up (a crude allowance for charger inefficiency) and that's the minimum charging time in hours, if the phone can fast charge from a varying supply. I think many people prefer to charge a power bank instead of a phone because phones often chime when the current stops momentarily.

 

[Ming the Merciless]

Can you remember which of the 57 varieties of Galaxy it was, even?

But anyway, most hub dynamos are 6V 3W, so divide the Wh of the phone battery by 3, ignore the difference between 6V and USB's 5V and round up (a crude allowance for charger inefficiency) and that's the minimum charging time in hours, if the phone can fast charge from a varying supply. I think many people prefer to charge a power bank instead of a phone because phones often chime when the current stops momentarily.

Most batteries aren’t rated in Wh . Least they didn’t used to be.

 

[mjr]

Most batteries aren’t rated in Wh . Least they didn’t used to be.

If I remember rightly, most recent mobile phone batteries are 3.7V so times the amp-hour by that to get the Wh.

 

[raybo]

If you've ever used one, do you have a sense of how the PedalCell compares with a hub dynamo in terms of performance? (I appreciate that the two different devices will have their own pros and cons depending on their different use cases) Thanks.

I haven't ever used a hub dynamo, so I can't really respond to your question. Sorry.

 

[Ming the Merciless]

If I remember rightly, most recent mobile phone batteries are 3.7V so times the amp-hour by that to get the Wh.

and the charging is provided over USB so different voltage again.

 

[Baldy]

Are these available over here or do you need to order from the US?

 

[mjr]

The main weakness of tyre dynamos was a tendency to slip in wet or frosty weather once the dynamo track became worn. How does the pedalcell perform in those conditions?

 

[raybo]

Are these available over here or do you need to order from the US?

I live in the US. I don't know if they are available elsewhere. Check the website: https://pedalcell.com .

The main weakness of tyre dynamos was a tendency to slip in wet or frosty weather once the dynamo track became worn. How does the pedalcell perform in those conditions?

I haven't ridden with the PedalCell in the rain. I never experienced a slippage when I was testing it, but, again, this was in "normal" riding conditions. I did go through water here and then, but that isn't what you are talking about. One of the video reviews on the PedalCell website shows a guy riding single track in all kinds of conditions. He doesn't mention slippage problems.

Note that the O-ring that sits against the wheel is replaceable. So, if slippage due to wear was a problem, replacing the O-ring might fix it.

 

[KnittyNorah]

The company seems happy to ship internationally and has sensible policies in place for it.

 

[Milkfloat]

Not exactly cheap is it? I cannot see too many people on long distance tours spending that amount of money that clamps on and is vulnerable to damage from knocks.

 

[neil_merseyside]

How much? Velocharger and hub dynamo (yes I know it's actually an alternator) is a good bit cheaper even without the shipping and import taxes/duties, or DIY this:- https://www.instructables.com/10-BICYCLE-USB-CHARGER/ the circuit is easy enough, the plastic about a tenner to get 3D printed.

 

[mjr]

Note that the O-ring that sits against the wheel is replaceable. So, if slippage due to wear was a problem, replacing the O-ring might fix it.

I would be more concerned about the tension of whatever springs presses the dynamo into the rim being insufficient for bad weather, reducing over time and increasing slippage. A rubber O-ring on metal sounds like lower grip than the rubber on tyre of a bottle dynamo and slippage was a problem in extreme conditions there.