I'd like to be able to charge up a leisure battery by bike. I've looked online and the equipment basically looks the same sort of set up as a turbo trainer. I'm wondering if I can modify my existing tt. I realise I'll need a battery, and an inverter for the power-out side but what for the charging side?

No numbers here, but you'd need an awful lot of pedal power to do that. It would probably be more effective to look at solar charging – unless you want to spend all night every night like a hamster!

Technical stuff:

bicycle-generator-faq

Is thiswhat you're looking for?
<EDIT> oops, just checked the link above.

You probably make 150W-200W ish on a turbotrainer. If a leisure battery is 100Ah then it's 1200Wh, ie 1200 Watt hours.. so you'd need to be riding say 8 hours to charge the thing.

Plus you'd need a generator, suitable transformers and a charging circuit. Which wouldn't be 100% efficient so you're looking at 10 hours or so riding I'd guess.

Thanks for that. Very interesting and useful.

It's for the caravan – going somewhere away from electric hook up (£3.40 per day) and wanting to run eg the laptop and some lights. I really need to add a battery and inverter so I can run the laptop safely (I think). The fridge can run on gas if necessary, but then that's extra cost.

I have a small petrol generator now. Heavy, polluting and noisy, plus uneven power. Only produces 750w – not cheap, but not horrendously expensive.

Bike generator. Have the bike, have the turbo trainer. Need a battery, inverter, and other bits and bats so cash outlay plus extra weight of battery and inv (but I need those anyway). Bike is quiet, non-polluting but it might be a pain if I was tired and the battery was flat!

Solar. Yes, again need battery and inverter plus panels and smart charger. Silent, non-polluting, but cost would be the major factor plus weight.

Molgrips – that's a lot of riding, I wasn't prepared for it to be that time intensive.

If you're doing the hours on a tt anyway then you might as well lash an alternator from a scrappy onto your kit and see what you get out of it! 🙂 If you do an hour or so a night during the week and don't tend to flatten the battery at the weekends then it might be workable. Probably a nice way of getting yourself to put some extra hours on the thing! 😉

Interesting article:

http://www.bicycling.com/tourdefrance/article/0,6802,ss1-3-11-21021-1,00.html

If you cycle with a power meter, you know that a fairly strenuous ride yields an average of about 140 watts for an hour. Mount your bike to a generator, slice off 30 percent for mechanical and electrical losses, and you've put out a measly 100-watt average during your sweaty hour. It amounts to around a penny's worth of electricity, one three-hundredth of a typical home's daily use—not enough juice to run the PlayStation for 15 minutes.

So you'll spend more energy producing than you'll get – which is fine if you are a fit fatty with a spare 6 hrs a day!

How about a split charger on your car and charge the leisure battery up driving to / from work as well? Or get an inverter and charge the laptop at the same time? Or charge a spare laptop battery at work?

I would like to patent one thats linked directly to the TV (that would help sort out the nations weight problems). 🙄

140w/hour is pretty easy riding tbh for even most weekenders, if you are male. If I go on a general ride pretty strenuously for say 4 hours I can average 230 ish watts.

And since when do Playstations use 400W?

Put it another way though – you could probably run a laptop and a small light on a 1:1 ratio for the energy you make cycling. So an hour of biking would maybe roughly equal an hour of laptop and light. Or maybe up to 2, depending on how fit you are and how power hungry your laptop is 🙂

for those like me who arent so techie…can we use our current turbos for this or does it require us to fit a new flywheel with the generator inside? I love the idea of this even if its practical benefits are small but I also love my virtual reality so dont want to give up my current set up. Can it be done more along the lines of the old style dynamo light?

I don't drive to work – only usually use the car once or twice a week.

Fit but not fat and def not 6 hrs a day spare! Oh, disappointed now.
I appreciate the efficiency is low, but still I feel attracted by the feel-good factor of making your own electricity, but then, the manufacture of the equipment and transporting it to me probably will result in a net loss environment-wise.
🙁

I can see a market for a bob trailer mounted leisure battery and dynamo you can attach to a bike for road rides…

I don't drive to work – only usually use the car once or twice a week.

Fit but not fat and def not 6 hrs a day spare! Oh, disappointed now.
I appreciate the efficiency is low, but still I feel attracted by the feel-good factor of making your own electricity, but then, the manufacture of the equipment and transporting it to me probably will result in a net loss environment-wise.
🙁

Ooh, this reminds me of my thread the other day…

I'd love to see more ways of generating energy from activities such as cycling. Surely you could generate enough to charge a mobile 'phone, riding an hour or two each day? Every little bit helps, I reckon. And if there was more investment in the development of the technology, then surely this kind of energy production would become more efficient?

Problem is that generators, particularly rotational electical machinery, have been being improved for decades, they're fairly close to their max without some breakthrough tech. Sure you could use your dyno powered lights to charge your phone, but the amount that actually takes is so negligible that the additional parts would cost more than the power required for a years cycling. Fun to hack together, easy to add to a product, but worth while? Hard to know if there's a market.

I remember a kid at school who came from a fairly odd family but one cool thing they did have was a dynamo powered telly. Only a little thing but it was the only telly they had and the dad, who clearly had some fairly strong ideas both about telly and cycling had told his kids they could watch as much of it as they wanted as long as they powered it themselves.

It was INSANELY hard to pedal for more than a couple of minutes although the kid, whose name I forget now, could keep it going for a good ten or fifteen minutes. Him and his brother would take it in turns spinning away when there was something on they wanted to watch.

IIRC it was a very simple setup with an old electric motor on the wheel, some basic electronics (an inverter and a big capacitor) and that was pretty much it. They had to keep an eye on a multimeter display to keep the voltage above a certain level.

Fit but not fat and def not 6 hrs a day spare!

Do you need to recharge the whole battery every day tho?

ARGGGHHHHH RPM not RPMS

YOu should be able to run your laptop off 12 v I would have thought not 240 – so no need for an inverter for that. Saves some conversion inefficiencies.

You might be better off with a wind generator – basic home made ones can be done very simply – a couple of cut up oil drums a couple of car wheel bearings and a alternator from a car.

If I had a more permanent set up I would love to build a wind turbine out of oil drums, looks like a great idea.

Looks like pv panels may be part of the answer for me – in the summer. In winter I would need the grid.

I agree with Mr T, if everyone produced just a small amount of power themselves it would make a lot of difference.

My best idea yet (IMHO), and this is for folks who have a midden nearby, is to run central heating pipes through the midden and into your house. Have you ever seen how hot the middle of a dung heap gets?

Some relevant products

http://www.ethicalsuperstore.com/products/powerplus/gazelle-pedal-powered–rechargable-dc–ac-powerbank/

Charge off your dynamo:

http://www.instructables.com/id/Portable-USB-battery-pack-bike-light-with-a-Luxeo/

http://www.copycatsolar.com/index_files/Page7674.htm

Also they now do a DC dynamo!

http://www.copycatsolar.com/index_files/Page2041.htm

http://cgi.ebay.co.uk/Bike-%2f-Bicycle-USB-Charger-for-Hub-%2f-Bottle-Dynamo_W0QQitemZ270553252573QQcmdZViewItem?rvr_id=&rvr_id=&cguid=27177da11210a0aad3638a63fffb893d

Actually not seen this one before today ^ (…a simlar product is coming from a german company and fits into the headset, but £150!) FInally a reasonable price 🙂 I may give it a go