I put Lipos in my K2 years ago (photos are on my website), they are still going strong and hold a charge for years. But if I was going to do it now I would put 4 of the A123Systems M1 LiFePO4 cells in. 2.3AH and no danger of venting to flame. They can be charged from 14.6-14.8V and if desired a small balancer built into the rig so no fancy charger would be required. They can handle large charge currents so as long as the voltage is not too high the charging system could be as simple as a schottky diode and current limit resistor.
A nice project Elecraft or someone could do would be to make a kit for that, with a nice little balancer and charge controller using a micro. The cells can be reconfigured into series-parallel for charging from conventional 12 volt sources, that might be a nice additional touch. -- Alan On Sat, Oct 17, 2009 at 12:24 AM, Johnny Siu <vr2...@yahoo.com.hk> wrote: > Hello Leigh, > > It is nothing complicated. I measured the size of battery mount of KBT2 and > bought 3 retangular shape Li-po cells to fill up the mount. > > For charging circuity, I just used what Don W3FPR mentioned in his webpage. > Of course, the best way to charge the Li-Po cells is to use an intelligent > balance charger which usually can be found in radio control players. > > The danger of using Li-po cells is usually related to overcharging or over > discharging. In any event, charge the Li-po cells with a intelligent charger > with both voltage and current control. > > cheers, > > Johnny VR2XMC > > > > ________________________________ > 寄件人﹕ Leigh L. Klotz Jr WA5ZNU <le...@wa5znu.org> > 收件人 elecraft@mailman.qth.net > 傳送日期﹕ 六, 10月 17, 2009 2:15:58 AM > 主題： Re: [Elecraft] [K2] Re： has the k2 a future? > > > Johnny, > Do you have pictures posted? I remember when you started this project and > I'd like to see how it worked out. > > Presonally I lean more toward LiFePO4; although they have a lower energy > density than the Li-Po (though higher power density) they reportedly are > safer in conditions of over/under charge and mechanical stress. > > Leigh/WA5ZNU > > Johnny Siu wrote: >> >> Hello Wayne, >> >> Yes, K2 is still my favourite field day and QRP rig and no others can bit >> it. >> >> I now have 3 x 3.7v 3300mAH Li-Po cells in the KBT2 and they work very >> well. >> >> 73 >> >> Johnny VR2XMC > > > > Yahoo!香港提供網上安全攻略，教你如何防範黑客! 請前往 http://hk.promo.yahoo.com/security/ 了解更多! > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
