I want to rig-up a bicycle generator as a backup charger for the 2.4kw/24v lifepo4 battery in my portable rig. If I use a mounted turbine of the appropriate voltage/wattage and don’t push for 100% SOC, is there any reason I can’t just plug into the SAE that connects to my Epever Tracer 40? Should I setup a dedicated input port/charger just for “wind” power? I do have room to expand but prefer not to; will probably use a max 1000w turbine.
Adding Pedal Generator via MPPT
- Thread starter SolarOhio
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schmism
Solar Addict
I don't think my understanding is on the same page of what your specifying.
As I understand (and quick confirmation here https://en.wikipedia.org/wiki/Human_power) " An adult of good fitness is more likely to average between 50 and 150 watts for an hour of vigorous exercise " You mention a 1000w turbine as a bicycle generator?
I don't mean to imply you arn't lance armstrong posting on the DIY solar forums but.... I'm having a hard time reconciling the above two numbers.
To put that in perspective, (if i did the math right) it will take ~10hrs of cycleing to charge a cell phone.
As I understand (and quick confirmation here https://en.wikipedia.org/wiki/Human_power) " An adult of good fitness is more likely to average between 50 and 150 watts for an hour of vigorous exercise " You mention a 1000w turbine as a bicycle generator?
I don't mean to imply you arn't lance armstrong posting on the DIY solar forums but.... I'm having a hard time reconciling the above two numbers.
To put that in perspective, (if i did the math right) it will take ~10hrs of cycleing to charge a cell phone.
There are plenty of videos of people using small bike generators to charge 12v batteries and power inverters to run small-mid watt devices. I think a full 1000w of pedal power would be a challenge, but I see no reason why a few hundred watts of steady charge power wouldn’t be easily possible with a fairly small bike-mounted turbine. I just want to know if that’s safe for my SCC as direct input instead of (not simultaneous) solar input.
There are also some Youtube video's that explain scientifically that you will get very little power from pedaling.
A trained athlete, on a generator-linked bike frame, can generate about 100W of power.
Pedaling for an hour will produce 0.1kwh of power.
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It would cost you much more in fuel than you would save from generating electrical energy this way. Cut down on treats for a month or two and buy yourself a PV panel.
Actually, no, practicalities aside ... if you actually wanted to do this for shits'n'giggles, then no, an MPPT charge controller would likely not be your best option. The SCC would be constantly changing the load characteristics in order to find and maintain the maximum power point (of a PV array).
If you already have a generator providing a DC output, I would use a simple wide-range DC-DC battery charger to charge my battery e.g. 6V - 60V input, 14.6V max output. Something like this for $10 maybe:
Edit: added product suggestion.
Actually, no, practicalities aside ... if you actually wanted to do this for shits'n'giggles, then no, an MPPT charge controller would likely not be your best option. The SCC would be constantly changing the load characteristics in order to find and maintain the maximum power point (of a PV array).
If you already have a generator providing a DC output, I would use a simple wide-range DC-DC battery charger to charge my battery e.g. 6V - 60V input, 14.6V max output. Something like this for $10 maybe:
Edit: added product suggestion.
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The bike generator would have to produce battery nominal voltage plus 5 volts for the solar charge controller to being sending a charge to the battery. Then it's plus one volt to continue charging. That's how Victron charge controllers work. I suppose if you pedalled like crazy to get the charge started you could slack off a bit after that.
Personally, it sounds like a lot of work to me. ?
Personally, it sounds like a lot of work to me. ?
It sounds like if nothing else, there is no way I’m going to generate enough energy to burn out a controller. The scenario I’m planning for is a lengthy power outage with no sun, which we have often in Ohio. Using outlet timers, I can stretch my 2.4 system to support 2 loaded refrigerators/freezers for 2-3 days, but if there is 0 solar input available possible during that time, then things get weird. 100w/hr actually isn’t the worst option in a truly dire situation — but it’s probably more feasible to add an AC charge option to my system. Then I could lug it around to find power or charge it from an inverter via car.
schmism
Solar Addict
The human power option I have only seen used in third world countries were a kid is on a stationary bike so the family has enough power for LED lighting in the evening. I dont know anyone that is willing to spend 4 hrs on a bike pedaling for 20 min of cell phone use.
Also living in the midwest our longest time of no-sun comes in the winter. And if your planning for a worst case senerio for in the winter then you might as well look at a thermoelectric generator to put ontop of a wood stove to make the same kind of output that the stationary bike would.
The reality is in the summer there is nothing that is going to generate enough power to keep your fridge going long term other than the sun or if you want to build a wood gasifier for a generator.
Also living in the midwest our longest time of no-sun comes in the winter. And if your planning for a worst case senerio for in the winter then you might as well look at a thermoelectric generator to put ontop of a wood stove to make the same kind of output that the stationary bike would.
The reality is in the summer there is nothing that is going to generate enough power to keep your fridge going long term other than the sun or if you want to build a wood gasifier for a generator.
A small hand crank flashlight unit can easily charge a phone or portable power bank for much longer than 20 minutes of use in an hour — close to 50% the last time I did it. I do agree that bike-powered alone doesn’t present a feasible solution for a prolonged emergency or off-grid situation, but 100w+/hr would be one hell of a phone charger, no?
700w! It can be done
Ampster
Renewable Energy Hobbyist
Yes, but that Olympian only did that rate for a minute or two. He generated 0.021kWh or 21 Watt hours. How many Watt hours you need is only limited by how much time you have and how hard you want to pedal..700w! It can be done
700wH700w! It can be done
How long does a toaster take to make toast toasty?
Less than an hour?
My toaster pulls about 900 watts for 5? minutes so 75watt hours.
Ampster
Renewable Energy Hobbyist
I bet they could have put 2 pieces of toast in there. Total sand-bagging...
No need to make fun of my toaster and I like my toast black.
I saw that video a while ago and what stood out to me was that the peddler looked way too bulked up to be a pro cyclist.
Video was over dramatized.
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