RC battery!! Is This Battery Applicable??

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etard   1 MW

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RC battery!! Is This Battery Applicable??

Post by etard » Sep 03 2008 7:50pm

Found this battery on Hobbyking after looking at the RC Motor build by scottclarke, and thought 2 of these might do well for a similar build. This battery is rated at 22.2 volts and 3700mah at 20C for under $100!! That sounds cheap. Are Li-Po batteries considered unsafe? My main reason for using these RC batteries at low voltage with high amps, would be for modular flexibility, in that, if I needed more range I could just pack second or third battery while keeping my bike as light as possible. Is this feaseable? Yes I am a noob, but I am very tired of my hardtail, and am ready to invest in something faster and plusher. Help me out O wise sages (trying to learn from your mistakes)...

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johnrobholmes   1.21 GW

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Re: RC battery!! Is This Battery Applicable??

Post by johnrobholmes » Sep 03 2008 11:19pm

For decent range you would want at least 3 of them in parallel. If you were to want higher voltage you would need 2s2p (12s2p technically) or even 2s3p, which is $600 in cells. 10C cells would be a better fit on a bike IMO, as the discharge rate is not as important as the runtime.

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johnrobholmes   1.21 GW

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Re: RC battery!! Is This Battery Applicable??

Post by johnrobholmes » Sep 03 2008 11:29pm

Looking around, those packs have a pretty good cost per watt/hour as compared to most reputable vendors. Charging so many packs will be your only problem really, otherwise they look like a good current market buy assuming the cells aren't total junk.

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stew007   10 W

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Re: RC battery!! Is This Battery Applicable??

Post by stew007 » Sep 04 2008 7:53am

they are fairly safe if you use a good quality balance charger like the cellpro, Hyperion or Graupner etc and you must have a low voltage cut off installed at no lower than 3.3v per cell, a cycle analyst has this feature when using it with the ebikes.ca controller.

I would use 3 of those batts in parallel to give 11.1ah x 2 to give 11.1ah at 44.4v, you can charge the three in parallel, but to do this you MUST also connect the balance leads in parallel too.
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John in CR   100 GW

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Re: RC battery!! Is This Battery Applicable??

Post by John in CR » Sep 04 2008 8:38am

I've been eye-balling some of the cheaper Zippy packs, since I'm running higher voltage and 10-15C is plenty of current for me. If you can find them the NiMH RC packs can be significantly cheaper though not as light, while still delivering high current. If you're after the smallest lightest packs for short trips, then RC packs will be hard to beat, however, you really have to look at range and also consider the limited cycle life compared to some of the other lithium cells. A lot is going to depend upon what motor you use too. eg If you're going to run an RC motor, then yes the lower voltage will work, but you need high current. You can't have your cake and eat it too (at least not yet) with high power, long cycle life, and low price batteries.

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andys   100 W

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Re: RC battery!! Is This Battery Applicable??

Post by andys » Sep 04 2008 10:25am

I am using an RC LIPO as a booster pack to get another 11.1V 10AH added to my 37 Volt 10.5AH Lithium pack I got from E-Bikes.CA. So far it has worked out well for that purpose. I have it wired in like a "turbo" that I can switch on when extra power is needed. As an only power source though, I think charging all the packs individually is a hassle, and when you add up all the costs,(3 or 4 packs, multiple chargers) you can get a ready made E-Bike lithium battery for not much more that will work better in the long run. I also wonder how they will do strung together without a BMS to regulate output. If the LIPO batteries do somehow get out of balance, they can become unstable, especially if any of the cells drop below a certain voltage.

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etard   1 MW

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Re: RC battery!! Is This Battery Applicable??

Post by etard » Sep 05 2008 12:49pm

Thanks for the input, I was wondering how I would go about wiring in another "booster pack". Does it have to be of the same battery type? I have 36v sla and am running the WE kit stock, I need more power, and just a mile or two more range. Is there a thread on the booster pack with switch wiring? Can I set a booster for more range, switchable to "turbo"?
Four wheels moves the body, Two wheels moves the soul
Thanks to Justin @ http://www.ebike.ca He brings the soul to ES

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