Step-up Booster/joule thief/buck converter for project? Will it work?

Battery & Chargers
1

Hi, I am wondering if I can get more knowledge on the Step-up Booster, they are also called joule thief, Buck converter and other nicknames.

So I have a motor that needs about 50 watts, draw about anywhere from 4 amp to 13 amp, at about 6-12 volts.
The condition is that we want to have the lowest possible weight for the battery that can get the motor going for at 5 minute. And it requires to be NiMh-battery

After some consideration, AA batteries seems to be very efficient but since we have to pull so many volts, it means we will have multiple cells (1 nimh is equal to 1.2v). So I was thinking maybe if we can magically increase the voltage we should be able to pull it out with ONLY 1 high capacity and discharge rate AA battery instead of having multiple low capacity ones.

Are step up boosters ready for these kind of abuses? If not really, maybe with a unique set up or something more magical?

It’s something like this: www dot ebay dot com/itm/like/260826436361?ul_noapp=true&chn=ps&lpid=82]DCDC Converter 3 25V Step Up to O P 5 25V 2A Adjustable Power Supply Module | eBay
but I think there are better ones out there.

Anyway, this is the motor I was looking at www dot flybrushless dot com/motor/view/54
And our team is trying to get a flying airplane with the lowest battery weight that can fly for 5 minute.

Thanks for any input you can give! Send any urls for me to take a look! Much appreciated!

2

My math say that a 2600mh AA cell will supply 3.2 amps for 5 minutes @ 10 volts.

That is if the 2600ma cell could dump it’s full rated power in 5 minutes. Which it can’t.
I’d bet on a tenth of that.
And 100% conversion efficiency.

So I’d say no!

The boost converter theory is valid.
The cell chosen must supply enough energy ie. VAH or watt-hours plus conversion losses.

3

This is similar. I’ll look for something closer.
The E2 is lithium.

4

Actually it looks better than I thought up to 1c discharge.
But you are talking >12c discharge,:wink:

5

I really appreciate your help! Yes, I been digging around about the discharge rate of the Nimh, which seems to me that it can take some abuse, some say that it can take up to 20C rating without explosion, hehe.

If 1 AA cell can’t do the step-up voltage alone, then using 2 of them together wouldn’t do too much harm. I mean as long as I can get the traditional 5 or 6 cell down to just 2, it’s great. ANY method even if it means murder!

And yes, the conversion efficiency is not 100%, I found some converter that gives about anywhere from 90% to 95% but it doesn’t meet the maximum amp discharge rate I was hoping for, so I still need to dig some shopping around.

6

Here is one that might be worth testing with say, 3 or 4 aa cells.

Max 5A LM2587 Step Up Boost DC Regulator Converter Inverter DB | eBay

7

I just found a good one…way too good for my expectation…

www dot amazon dot com/LM2577-Adjustable-Step-up-Converter-Module/dp/B008HMETBE]Amazon dot com: niceEshop™ LM2577 DC-DC Adjustable Step-up Power Converter Module: Electronics

What do you think about this one? I am thinking about even doing just 1 cell with this little thing, maybe 2 if things don’t work out.

8

Couldn’t follow the link.

Just remember when just using one cell @ 20C and 8X the voltage, you will only get 1/160 of an hour run time @ 6.5A out. (@ theoretical best)