Another Dynamo Q

[Bearbonesnorm]

Hopefully a very simple one ... if you use a Kemo do you need a 'buffer battery' downstream of the device you're trying to charge?

My understanding is that the Sinewave controller doesn't - is that correct?

Ta

[Mark E]

I've just bought a fuel battery to use as a buffer with my sinewave revolution. Whilst it doesn't strictly need it, I'm hoping it will get rid of the annoying 'external power lost' signals my edge 800 gives out. This is a problem if it is connected directly to the revolution and speed drops below that required to maintain a charge (all too often for me when riding off road)!

[Taylor]

I have the same problem with the Sinewave revolution so use a buffer to charge during the day then that charges my phone overnight, otherwise the phone beeps at me when I'm on a long slow climb.
I think a buffer is probably a good thing whichever hub/kemo/Sinewave combo you opt for.

[ianfitz]

As mark says a battery will remove the loss of charge. But I use a kemo and as it has a switch will just turn the lights on at low speeds. Flick it back to charge once I speed up a bit.

Gives me something extra to distract me on long rides!

[composite]

It will depend on the behavior of your GPS unit when there is not enough power to charge it. Interrupted charge is only a problem if your GPS lets you know that the power has stopped in an annoying way, as does the Garmin Edge 800. To stop that you will need a separate battery downstream.

There are a number of regulators that have a built in battery such as the Super-i-Cable, the Busch and Muller USB Werk and the ReeCharge. However they are all normally quite small and are really only there to act a a reservoir rather than a proper power store.

[johnnystorm]

The Reecharge battery is an optional extra.

[jameso]

I used an adapted Kemo with K-lite 'magic mods' for 900mah output and no added cache cells on my last road ride, the power-lost on the Garmin 800 was a minor frustration in towns. I've now got a B+M USB-Werk that has a really small cache battery, £55 on Rose bikes. It'll avoid the charge-loss screen and work with a higher-output eternal cache battery if I need the option. Will see how the lower 500mah output of the B+M affects things - for road use 900mah charged things pretty quick.

[larsmars]

+1 for the Sinewave Revolution + cache battery to solve the annoying charging beeps and brightness reset on the Edge 800. Also nice to be able to recharge later off the bike when needed.

[ianfitz]

I used an adapted Kemo with K-lite 'magic mods' for 900mah output and no added cache cells on my last road ride, the power-lost on the Garmin 800 was a minor frustration in towns. I've now got a B+M USB-Werk that has a really small cache battery, £55 on Rose bikes. It'll avoid the charge-loss screen and work with a higher-output eternal cache battery if I need the option. Will see how the lower 500mah output of the B+M affects things - for road use 900mah charged things pretty quick.

What's the klite mod? Do you have any info??

[jameso]

What's the klite mod? Do you have any info??

Sorry, no .. a Q to ask Kerry directly. He'd adapted it and sent it to a rider he supports and I just borrowed it.

[jameso]

http://www.maplin.co.uk/p/kemo-bicycle- ... oC2u_w_wcB

Minor PSA perhaps. The Kemo's now £30 from Maplin. Not sure if they've had them long, I searched about 2 months ago and only saw them from Kemo direct.

[composite]

http://www.maplin.co.uk/p/kemo-bicycle- ... oC2u_w_wcB

Minor PSA perhaps. The Kemo's now £30 from Maplin. Not sure if they've had them long, I searched about 2 months ago and only saw them from Kemo direct.

That looks a lot tidier than what they were selling when I looked at them I'm sure.

I remember looking at them and thinking it looked like a component from something else.

[DoctorRad]

The kLite mod is to put a 'booster' capacitor in series with the dynamo input. This acts in conjunction with the inductance of the dynamo coil to provide a boost in current at cerain speeds.

You can either use a bipolar capacitor, or two electrolytics. Compare Circuits 2, 5 and 6 on this page to get the fundamentals: http://www.pilom.com/BicycleElectronics ... rcuits.htm