Dynamo charging

[HUX]

My new wheelbuilding fetish has led me into buying 2 new dynamo hubs. ( 1 for a bike I don't even own yet ) . So what is the cheapest gadget to charge a battery pack from a dynamo hub. I seem to remember someone mentioning something from Maplin a while ago. I may even run a light off it. Any suggestions? Cheers

[sean_iow]

The one Maplins used to sell was a Kemo bicycle charge controller. If I'd remembered about them I could no doubt of got a bargain in the closing down sale A quick goole suggests they are still available from other suppliers.

[Bearbonesnorm]

Yep, Kemo is probably the cheapest option. They work okay too.

[ianfitz]

I think I have a Kemo spare somewhere

Pm if interested

[whitestone]

Welcome to another world of pain! Opinions on whichever brand/model you get seem somewhat polarised

I've not had experience of the Kemo but another option might be the VeloCharger Hub. Cath has one for her dynamo hub. It's a little bigger than the single cell 18650 powerbank devices. Seems to have gone up considerably in price since earlier this year though, I think we only paid £45 or so. After that you are up to and over the £100 mark for things like the eWerk and Igaro D1 (which I have).

From manufacturers' sites and various forum discussions: don't put the charger in a bag to protect it - they heat up so need a flow of air to keep them cool. Don't run them open circuit, especially on long road downhills, always have a load attached even if it's not "doing anything". I think someone fried an Igaro doing the latter from memory.

Finally be realistic about what you can charge/recharge. Here's my experiences from a couple of weeks' riding in France - http://bobwightman.blogspot.com/2018/08 ... onics.html with some "real world" observations rather than lab results.

[ctznsmith]

What?

I've run a B&M USB-werk for years in a bag with sometimes nothing plugged in for days. I guess the tiny cache battery in one of those stops the open circuit problem but my usb-werk doesn't get hot (or even noticeably warm).

[HUX]

Thanks folks. Ian pm incoming

[thenorthwind]

Not sure what passes for cheap, but I thought the Cycle2Charge was reasonably priced when I bought it.

I think Stu has one of these too and did an initial review - any updates to add?

Interesting what you say about needing a load attached Bob. I hadn't really though about it (should have done really, I'm an electrical engineer), but I suppose the passive components will still generate loss with no load so it's not impossible. If it's actually causing failure issues then I would argue its poor design.

The Cycle2Charge is probably less likely to suffer from this if it were a problem, as by it's nature it's exposed and getting a good flow of air.

Mine hasn't had extensive use, but I've used it quite a bit. However, I swapped my dynamo wheel back into the relevant bike for an audax at the weekend, and couldn't get anything out of it but momentarily. I've yet to investigate (could be a cable, or the dynamo) but I'll try to remember to update this when I do.

[pistonbroke]

Leigh, there are 2 models of Kemo, I have the M172 which is about half the size of the M172N and outputs 300mAh against the N's 800mAh. Depends how much space you have to mount it, they're both about €30 from Conrad.com the N model has a standard USB port so you can connect a range of different powerbank buffers whereas the smaller one has a fixed mini USB wire output and a mini to micro adapter which is a bit of a disadvantage as there are very few powerbanks that have a mini input and having an adapter increases the number of joins in the system so more to fail/get moisture in. I've used the 2 I've got for a long time and they've been trouble free. You can switch between powering a battery or straight through to a Revo light but not both. On my gravel bike, I've wired it through a 2000mAh Juice cube to my Garmin Edge Touring and I often start rides with 50% battery on the gps and come back with it full. Linky http://www.conrad.com/ce/en/product/860 ... archDetail

[HUX]

Great stuff cheers Duncan

[HUX]

Ian. Pm seems to be stuck in outbox at the mo but I'm interested in the kemo. Hux

[whitestone]

Ian. Pm seems to be stuck in outbox at the mo but I'm interested in the kemo. Hux

Until he reads it, it stays in your outbox.

[thenorthwind]

Re. what I wrote up there: it was definitely the cable, so no reflection on the quality of the Cycle2Charge.

(Related: where can I get a reliable short (30cm - 50cm) micro USB cable with a right angle plug at the USB end, which is either reversible (ideally, but I think therein may lie the unreliability) or the right way for my GPS?)

[Trail-rat]

My cycle2charge were junk - all three of them.

Killed my gen 1 igaro by running it open circuit and hitting 70kph off the Rockies for extended periods.

Igaro d5 going strong still

[whitestone]

Re. what I wrote up there: it was definitely the cable, so no reflection on the quality of the Cycle2Charge.

(Related: where can I get a reliable short (30cm - 50cm) micro USB cable with a right angle plug at the USB end, which is either reversible (ideally, but I think therein may lie the unreliability) or the right way for my GPS?)

What you need to search for is "angle up USB" or "angle down USB", can't remember where I got mine from, probably Amazon.

Edit: here you go - https://www.amazon.co.uk/CERRXIAN-9Inch ... 071YPWD48/

[thenorthwind]

My cycle2charge were junk - all three of them.

I don't know which version(s) you had, but mine is a v2, which I seem to remember reading has overcurrent protection on it (could be wrong).

Thanks Bob. I mean right angled in the opposite plane, but you led me to search for "angle left" which I hadn't thought of before (duh) and that seems to be what I'm after. I've got USB cables coming out of my ears, but never the right one! (Or in this case, left one.)