Any question answered...

Watch out, the mAh ratings of those things are often speced as the mAh capacity of the thing's internal 3.7V battery rather than the number of mAh that you'll get out of it at 5V.

Shimano FC-S500/FC-S501 exactly matches your criteria.

Of course. Totally forgot about the Alfine. Thanks!
I have a 175mm crank at the moment, is that 5mm difference notable?
As you recommended it, does it get your Approval™? I don't expect any wonders from a £50 crankset, but I'd like it to be at least a little stiffer and smoother than the no-brand square taper crankset i had before.

If you can notice the 5mm difference, you won't after an hour of riding.

As I understand it the Alfine one is basically the same as a 105.

Watch out, the mAh ratings of those things are often speced as the mAh capacity of the thing's internal 3.7V battery rather than the number of mAh that you'll get out of it at 5V.

Does the Garmin need 5V? How do you know how much capacity the unit will provide at 5V?

Same one shipped from UK
http://www.play.com/Electronics/Electronics/4-/53748549/940663235/-/ListingDetails.html

Cheers, they're all a bit bulky though. I wanted to use it for on the go charging like the Garmin device that straps to the bars. I guess I could strip the case down and repackage the cells.

but I'd like it to be at least a little stiffer and smoother than the no-brand square taper crankset i had before.

It will be, as long as you get your BB shell faced if you haven't done so already. £15 or so at your LBS.

Does the Garmin need 5V? How do you know how much capacity the unit will provide at 5V?

How efficient is the boost converter?

If it's a USB connector, it's 5V (plusminus 5%). Li-ion [Cobalt] cells usually output 4.2V full and a safe circuit would cut off somewhere between 3.1V and 3.3V.

Capacity is inversely related to current drawn, so a cell which can deliver 1A for 5 hours is likely to run for less than 1 hour at 5A.

The combination of these effects is why device battery % capacity drops off a cliff below 25%: The voltage is lower when they're this empty so it takes more current at battery voltage to deliver any given current at circuit reference voltage.

How efficient is the boost converter?

Who said what now?

Ok: "USB power port spec, which is 4.75 to 5.25 volts for USB 1.0 & 2.0. USB 3.0 is 4.45 volts to 5.25 volts"

Aftermarket kits: http://www.batteryship.com/htmlos/htmlos.cgi/batteryship/catalog.html?item=KE37BE49D0DX3

AA pack for it: Gomadic Portable AA Battery Pack for the Garmin Edge 800 - Powered by 4 X AA Batteries to provide Emergency charge. Built using TipExchange Technology: Amazon.co.uk: Sports & Outdoors

http://farm9.staticflickr.com/8226/8395320364_274ea61065_z.jpg

https://forums.garmin.com/showthread.php?33752-Edge-800-Replacing-Battery-Pics-and-some-info-not-complete-yet

Powermonkey adds 2200mah https://www.powertraveller.com/en/shop/portable-chargers/outdoor-adventure/powermonkey-explorer:1/

Watch out, the mAh ratings of those things are often speced as the mAh capacity of the thing's internal 3.7V battery rather than the number of mAh that you'll get out of it at 5V.

See the first link for the biggest one - 30000mAh cell rating becomes 16800mAh true output. But then the 1100mAh internal unit is probably a cell rating too.

Cheers, they're all a bit bulky though. I wanted to use it for on the go charging like the Garmin device that straps to the bars. I guess I could strip the case down and repackage the cells.

The more capacity, the bigger they get. There's no getting around the basic physics.

If you can notice the 5mm difference, you won't after an hour of riding.

As I understand it the Alfine one is basically the same as a 105.

Nice, Thanks.

It will be, as long as you get your BB shell faced if you haven't done so already. £15 or so at your LBS.

Had that in mind already, will do.
Would it be advisable to spray the now "naked" faced surface with some kind of anti corrosion spray? Since my BB gets wet all the time, I'd expect some rust there otherwise...

The more capacity, the bigger they get. There's no getting around the basic physics.

Lies!

Bulky, as in square desktop-ish units rather than the tube style Powermonkey that fits neatly onto bikes.

Of course. Totally forgot about the Alfine. Thanks!
I have a 175mm crank at the moment, is that 5mm difference notable?
As you recommended it, does it get your Approval™?

5mm shorter cranks won't hurt you, even if you notice them (which most people don't, in blind tests)

I have two of them on the Tester Tandem. They are worth the money, if that's your budget, then that's my recommendation.

As I understand it the Alfine one is basically the same as a 105.

Alfine is nothing like 105, that's why it's half the price. It's more like FC-4600 Tiagra, i.e. not hollow.

Is it appropriate to thank a team of accountants in the form of a case of wine as a gesture of appreciation for exceeding the levels of performance for which they are paid? The accountancy firm has really helped me out including some of the admin team working on days off to help me get something sorted in time. I want to show my appreciation.

Take them to Spearmint Rhino.

How do you know how much capacity the unit will provide at 5V?

Some specify it, or you measure it roughly and use that number in an amazon review to troll the manufacturer into revealing the actual number. In the case of my 15000mAh Anker, that's 10500mAh. Amazon.co.uk: nick6483's review of Anker® Astro E5 15000mAh Portable Charger ...

Typically the converters are about 70 to 80% efficient I think. They output 5V and a fully charged Garmin only wants 4.2V to keep the battery topped up, so I expect it just discards the extra 0.8V, which is another 16% loss. It seems unlikely that they'd put in extra electronics to make slightly more efficient use of external power, but this is a guess.

So, the cost of using a USB cable to connect the external battery pack to the Garmin (rather than removing the Garmin's internal battery and macgyvering a direct connection to a battery taken from an external battery pack) is about 1/3 of the battery capacity.

I'd rather not socialise with them if at all possible.

5mm shorter cranks won't hurt you, even if you notice them (which most people don't, in blind tests)

I have two of them on the Tester Tandem. They are worth the money, if that's your budget, then that's my recommendation.

Alfine is nothing like 105, that's why it's half the price. It's more like FC-4600 Tiagra, i.e. not hollow.

Thanks for the clarification! repped!

I'd rather not socialise with them if at all possible.

Put them in a cab. Give driver instructions. Go home and watch funny cat videos.

Give them all a penny and say that you're so impressed with their monetary skills that you hope they enjoy the new house you just bought them in 5 years.

Ukraine safe holiday destination atm?

lolz.

I was just wondering whether accountants are allowed to accept gifts from clients. I'm not for example. I guess its just a case of plonk and not a wad of benjamins in a brown envelope.

I think over a certain value will likely have to declare it under recent anti bribery laws. Their company will keep a record but I doubt it would be an issue.

Ukraine safe holiday destination atm?

A friend of mine is on his/her way to Kiev for a year now. Ok he/she isn't allowed to say why and what for but I'm sure its safe as houses. :D

I think over a certain value will likely have to declare it under recent anti bribery laws. Their company will keep a record but I doubt it would be an issue.

Cheers mate. Cheapest plonk possible it is then.

Why not ask them:

"What are they best options for rewarding a supplier with a gift in such a way as to minimize tax liability of the recipient"