Re: [Elecraft] Replacing the Lead acid shell inside K2 with Li-Po cells
I thought about this and even bought a 3 cell battery and balanced charger - then I realised the dangers of LiPo and decided against it in favour of 10 2.5AH NiMH cells in a 5 over 5 holder. This fits in fine in place of the lead acid, is a lot lighter and can be charged quite easily with minor modifications to the K2 battery system. I am interested in the results though as I still have the LiPo and balanced charger. Mike Johnny Siu wrote: Hello Group, 3.7v 3300mAH Li-Po cells are cheaply available locally. Multifunction balance intelligent chargers are cheap as well. I am seriously thinking of replacing the lead acid cell inside the KBT2 with 3 x 3.7v Li-Po cells. However, charging of the Li-Po cells requires multifunction charger. The existing battery circuity inside K2 seems not fit for this purpose. A direct connection to the battery terminals is required. I would be grateful if any of you could advise me the 'do' and 'don't' that I should pay attention to. With the Li-Po cells installed, the weight of K2 QRP will be much reduced with more battery capacity. K2 is even more suitable for ARES purposes. Looking forward to your advice. TNX 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 -- View this message in context: http://n2.nabble.com/Replacing-the-Lead-acid-shell-inside-K2-with-Li-Po-cells-tp3740663p3740930.html Sent from the Elecraft mailing list archive at Nabble.com. __ 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
Re: [Elecraft] Replacing the Lead acid shell inside K2 with Li-Po cells
I think that dangers of protected Li-Ion batteries are way overblown. After all, millions of laptops with those batteries fly every day with no problem. The charging problems are overblown as well. What happens if the battery life is 100 charges and not 500 when you need to charge every two weeks. By the time the battery is weak it is obsolete. I have 2 x 3 pack of computer Li-ion cells (with built-in protection) in my K2 for 5 years. Charged via a 12.6V 1A regulator with a laptop PS. Light and zero problems. It seems that charging each cell 4.2V (or 12.6V for 3 cells) with some current restriction is a good enough technique for longevity. Ignacy AD6XY wrote: I thought about this and even bought a 3 cell battery and balanced charger - then I realised the dangers of LiPo and decided against it in favour of 10 2.5AH NiMH cells in a 5 over 5 holder. This fits in fine in place of the lead acid, is a lot lighter and can be charged quite easily with minor modifications to the K2 battery system. I am interested in the results though as I still have the LiPo and balanced charger. Mike Johnny Siu wrote: Hello Group, 3.7v 3300mAH Li-Po cells are cheaply available locally. Multifunction balance intelligent chargers are cheap as well. I am seriously thinking of replacing the lead acid cell inside the KBT2 with 3 x 3.7v Li-Po cells. However, charging of the Li-Po cells requires multifunction charger. The existing battery circuity inside K2 seems not fit for this purpose. A direct connection to the battery terminals is required. I would be grateful if any of you could advise me the 'do' and 'don't' that I should pay attention to. With the Li-Po cells installed, the weight of K2 QRP will be much reduced with more battery capacity. K2 is even more suitable for ARES purposes. Looking forward to your advice. TNX 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 -- View this message in context: http://n2.nabble.com/Replacing-the-Lead-acid-shell-inside-K2-with-Li-Po-cells-tp3740663p3742536.html Sent from the Elecraft mailing list archive at Nabble.com. __ 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
Re: [Elecraft] Replacing the Lead acid shell inside K2 with Li-Po cells
Johnny, Take a look at my website article to see how I connected a SmartCharger to the K2 internal battery. See www.w3fpr.com. True, the battery and charger are different, but the concept is the same. The battery connection should be fused for safety. 73, Don W3FPR Johnny Siu wrote: Hello Group, 3.7v 3300mAH Li-Po cells are cheaply available locally. Multifunction balance intelligent chargers are cheap as well. I am seriously thinking of replacing the lead acid cell inside the KBT2 with 3 x 3.7v Li-Po cells. However, charging of the Li-Po cells requires multifunction charger. The existing battery circuity inside K2 seems not fit for this purpose. A direct connection to the battery terminals is required. I would be grateful if any of you could advise me the 'do' and 'don't' that I should pay attention to. With the Li-Po cells installed, the weight of K2 QRP will be much reduced with more battery capacity. K2 is even more suitable for ARES purposes. Looking forward to your advice. TNX 73 Johnny VR2XMC __ 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
