Have you at any time measured that current draw under load on the larger ships? Are you aware of the specific ratings for the cells in question and the types of PTC's employed? Do you understand what the maximum draw might be demanded of that particular cell/pack?
The point is, although you have not observed "problems" this does not merit blanket approval of their operation in all circumstances. I wish folks would refrain from the mindset "if it works for me it must be OK to recommend to others without reservation", which therefore gives the green light to others that indeedy there is no problem... I'm happy they are working for you, but by no means jusify their use without evidence to show that: a) actual supply V remains above RX and servo thresholds b) onboard PTC's have current limits that match the application c) their eservice life has not already been used within their original application(s) Quoting John <[EMAIL PROTECTED]>: > I use Li-Ion in 3 HLG's 7-9 oz ships AUW, and three 2M ships along with 2 > UNL ships. I use cell phone batteries in 1S and 2S configurations yielding > 4.4+v. I also use Cell Phone chargers for charging them. Most if the > Batteries and all the chargers came from discarded cell phones. I collected > them from cell phone shops that have upgraded customers and were glad to > part with them. I use 1S or 2S because I have RX that work fine with them > and have had no problems in the past 3 years. I went to a 2-day ladder > contest in Michigan and realized I forgot my charger. No problem. I didn't > need it. If you charge a 2S 18650 (from old laptop computers) to 4.4v it > will run for days without needing a recharge in my RES ships. One > 14430-600mah will last several flying sessions in my 60" Little Bird II or > QFII HLG. I have also used some of the flat rectangular cell phone batteries > in my HLG's in the past. They are harder to fit in the small ships but the > 2M and up are great candidate. If I were worried about current draw I would > go to 2S, 3S or even 4S with an ESC to step down the voltage. The weight > savings and convenience is phenomenal. Not to mention that you can't beat > the price. > > John > > > -----Original Message----- > From: Simon Van Leeuwen [mailto:[EMAIL PROTECTED] > Sent: Friday, October 20, 2006 12:36 PM > To: John > Cc: RCSE > Subject: Re: [RCSE] Lithium Ion batteries > > Very different technology; > > The charge algorythms used within cellphones and other personal equipment > are > locked down to the cell-count for that device, with other safegaurds. > > The original question about using Lithium technology for sailplanes, at the > moment it does not warrant their use for a couple of reasons. First the form > factor, those cells which would adequately meet the current demands are > relatively large (18650 - 18mm dia x 650mm length). Although the size of > prizmatics would fit our current moldies, they offer no where NEAR the > required > current demands due to their internal structure. > > I suspect the poster who used Lithiums in his sailplane was able to do so > because the aircraft's size allowed it... > > > Simon Van Leeuwen > PnP Systems - The E-Harness of Choice > Radius Systems > Cogito Ergo Zoom > > > Quoting John <[EMAIL PROTECTED]>: > > > I wonder if all the people that are still so worried about charging Li-Ion > > batteries are charging all the cell phones in the family outdoors in an > ammo > > box. :>) No different technology. > > > > John > > > > > > > > > > RCSE-List facilities provided by Model Airplane News. Send "subscribe" > and > > "unsubscribe" requests to [EMAIL PROTECTED] Please note that > > subscribe and unsubscribe messages must be sent in text only format with > MIME > > turned off. Email sent from web based email such as Hotmail and AOL are > > generally NOT in text format > > > > > > RCSE-List facilities provided by Model Airplane News. Send "subscribe" and > "unsubscribe" requests to [EMAIL PROTECTED] Please note that > subscribe and unsubscribe messages must be sent in text only format with MIME > turned off. Email sent from web based email such as Hotmail and AOL are > generally NOT in text format > RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off. Email sent from web based email such as Hotmail and AOL are generally NOT in text format
