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#1
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Hi,
I just added some new batteries to my web site tonight. They have been highly recommended to me by several sailplane pilots. New - Bioenno Power Lithium Iron Phosphate LiFePO4 12V Glider Batteries - Enhanced cycle life - up to 2000 charge cycles! After 2000 charge cycles, the battery still holds 75-80% of its original capacity. - Lower weight - less than half the weight of lead-acid batteries! If you are accustomed to using lead-acid batteries - you will be shocked the first time you pick-up one of these batteries. - Constant and stable discharge voltage - Lead-acid batteries gradually lose voltage over time as they discharge - dropping below 12V early-on. LiFePO4 batteries have a much more gradual decrease in voltage until they are nearly fully discharged - staying at 13+V for most of their discharge cycle - so they are able to power your sailplane radio and instruments at higher voltages for longer periods of time. Higher voltages assure maximum transmit power from radios and transponders. http://www.cumulus-soaring.com/bioenno.htm Best Regards, Paul Remde Cumulus Soaring, Inc. |
#2
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A comment on lithium batteries since I have two in my glider and a
digital volt meter mounted on the panel... I don't notice much voltage drop as I did with lead batteries other than when I transmit. The data available for the batteries indicates a rapid decline and shutoff when the battery is nearly spent. I don't think that's a problem since the shutoff voltage is around 9.6 volts and your radio will quit transmitting before reaching that limit. The reason I post this is because I was using a lithium powered flashlight the other day while working on my car and, when the battery reached it's limit, it simply shut off. It was so sudden that I thought the bulb had burned out. No dimming as you're used to with standard batteries. Changing the bulb had no effect so I swapped batteries with my drill and the light worked again. Charging the battery took less than an hour. On 4/15/2015 11:27 PM, Paul Remde wrote: Hi, I just added some new batteries to my web site tonight. They have been highly recommended to me by several sailplane pilots. New - Bioenno Power Lithium Iron Phosphate LiFePO4 12V Glider Batteries - Enhanced cycle life - up to 2000 charge cycles! After 2000 charge cycles, the battery still holds 75-80% of its original capacity. - Lower weight - less than half the weight of lead-acid batteries! If you are accustomed to using lead-acid batteries - you will be shocked the first time you pick-up one of these batteries. - Constant and stable discharge voltage - Lead-acid batteries gradually lose voltage over time as they discharge - dropping below 12V early-on. LiFePO4 batteries have a much more gradual decrease in voltage until they are nearly fully discharged - staying at 13+V for most of their discharge cycle - so they are able to power your sailplane radio and instruments at higher voltages for longer periods of time. Higher voltages assure maximum transmit power from radios and transponders. http://www.cumulus-soaring.com/bioenno.htm Best Regards, Paul Remde Cumulus Soaring, Inc. -- Dan Marotta |
#3
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On Thursday, April 16, 2015 at 8:04:05 AM UTC-7, Dan Marotta wrote:
A comment on lithium batteries since I have two in my glider and a digital volt meter mounted on the panel...* I don't notice much voltage drop as I did with lead batteries other than when I transmit.* The data available for the batteries indicates a rapid decline and shutoff when the battery is nearly spent.* I don't think that's a problem since the shutoff voltage is around 9.6 volts and your radio will quit transmitting before reaching that limit. The reason I post this is because I was using a lithium powered flashlight the other day while working on my car and, when the battery reached it's limit, it simply shut off.* It was so sudden that I thought the bulb had burned out.* No dimming as you're used to with standard batteries.* Changing the bulb had no effect so I swapped batteries with my drill and the light worked again.* Charging the battery took less than an hour. On 4/15/2015 11:27 PM, Paul Remde wrote: Hi, I just added some new batteries to my web site tonight.* They have been highly recommended to me by several sailplane pilots. New - Bioenno Power Lithium Iron Phosphate LiFePO4 12V Glider Batteries - Enhanced cycle life - up to 2000 charge cycles! After 2000 charge cycles, the battery still holds 75-80% of its original capacity. - Lower weight - less than half the weight of lead-acid batteries! If you are accustomed to using lead-acid batteries - you will be shocked the first time you pick-up one of these batteries. - Constant and stable discharge voltage - Lead-acid batteries gradually lose voltage over time as they discharge - dropping below 12V early-on. LiFePO4 batteries have a much more gradual decrease in voltage until they are nearly fully discharged - staying at 13+V for most of their discharge cycle - so they are able to power your sailplane radio and instruments at higher voltages for longer periods of time. Higher voltages assure maximum transmit power from radios and transponders. http://www.cumulus-soaring.com/bioenno.htm Best Regards, Paul Remde Cumulus Soaring, Inc. -- Dan Marotta I was wondering about this characteristic myself, but don't! I bought a Stark Power LiFePo4 battery and ran it until it was discharged. The voltage declined very slowly over the first 8 hours or so, then more rapidly over about the next 2 hours before I shut it off at 11.9 V. This led me to conclude that a) mine will last for a very long flight and b) the decline in voltage gives plenty of warning that it is near the end. |
#4
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Before we decided to sell the Stark Power LiFePo4 battery, we installed two of them in our DUO Discus. The DUO has lots of electronics in both cockpits including a transponder, Flarm, flight computers, etc, etc.
We flew on one battery for two long days, just to see how long they might last, and it still had lots of power left. We obviously now have both installed, and connected as we did with the previous batteries. We have sold a couple hundred of these with no complaints or problems, and they seem to be lower cost than others I am aware of. Even the important battery charger is reasonable in cost. They charge very quickly. At this time, we do not suggest using them for high power applications such as used in self-launch gliders. Tom Knauff www.eglider.org |
#5
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On Thursday, April 16, 2015 at 2:08:17 PM UTC-7, wrote:
Before we decided to sell the Stark Power LiFePo4 battery, we installed two of them in our DUO Discus. The DUO has lots of electronics in both cockpits including a transponder, Flarm, flight computers, etc, etc. We flew on one battery for two long days, just to see how long they might last, and it still had lots of power left. We obviously now have both installed, and connected as we did with the previous batteries. We have sold a couple hundred of these with no complaints or problems, and they seem to be lower cost than others I am aware of. Even the important battery charger is reasonable in cost. They charge very quickly. At this time, we do not suggest using them for high power applications such as used in self-launch gliders. Tom Knauff www.eglider.org I flew with the Stark Power Batteries for a flying season before I started selling them. Also did some tests with Electrofly charger battery discharger see results: http://www.craggyaero.com/lifepo_battery.htm Richard www.craggyaero.com |
#6
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Most small LiFePO4's are going to have a BMS (Battery Management System)
that disconnect the battery in event of excessive charging or discharging, since they're hypersensitive to those events. That's what you saw when the light went off instantly. If you were using an LED flashlight, it has an active regulator to control the LED's. Which would have hidden the voltage drop prior to cutoff. You can generally hear the switching circuit put out RF noise if you hold it close to an AM radio. -Dave On Thu, 16 Apr 2015 09:04:01 -0600, Dan Marotta wrote: A comment on lithium batteries since I have two in my glider and a digital volt meter mounted on the panel... I don't notice much voltage drop as I did with lead batteries other than when I transmit. The data available for the batteries indicates a rapid decline and shutoff when the battery is nearly spent. I don't think that's a problem since the shutoff voltage is around 9.6 volts and your radio will quit transmitting before reaching that limit. The reason I post this is because I was using a lithium powered flashlight the other day while working on my car and, when the battery reached it's limit, it simply shut off. It was so sudden that I thought the bulb had burned out. No dimming as you're used to with standard batteries. Changing the bulb had no effect so I swapped batteries with my drill and the light worked again. Charging the battery took less than an hour. On 4/15/2015 11:27 PM, Paul Remde wrote: Hi, I just added some new batteries to my web site tonight. They have been highly recommended to me by several sailplane pilots. New - Bioenno Power Lithium Iron Phosphate LiFePO4 12V Glider Batteries - Enhanced cycle life - up to 2000 charge cycles! After 2000 charge cycles, the battery still holds 75-80% of its original capacity. - Lower weight - less than half the weight of lead-acid batteries! If you are accustomed to using lead-acid batteries - you will be shocked the first time you pick-up one of these batteries. - Constant and stable discharge voltage - Lead-acid batteries gradually lose voltage over time as they discharge - dropping below 12V early-on. LiFePO4 batteries have a much more gradual decrease in voltage until they are nearly fully discharged - staying at 13+V for most of their discharge cycle - so they are able to power your sailplane radio and instruments at higher voltages for longer periods of time. Higher voltages assure maximum transmit power from radios and transponders. http://www.cumulus-soaring.com/bioenno.htm Best Regards, Paul Remde Cumulus Soaring, Inc. |
#7
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Thanks Dave,
The flashlight in question has an incandescent bulb. By excessive discharging I assume you meant low charge remaining, which was the case, rather than excessive current. It was interesting to see it simply switch off rather than dimming to nothing as the charge dissipated. In the case of my glider the switch off voltage is 9.6 volts which, I believe will still run my vario but will not run my radio. Therefore, I manually switch batteries when the radio stops working. On 4/21/2015 6:54 AM, David Kinsell wrote: Most small LiFePO4's are going to have a BMS (Battery Management System) that disconnect the battery in event of excessive charging or discharging, since they're hypersensitive to those events. That's what you saw when the light went off instantly. If you were using an LED flashlight, it has an active regulator to control the LED's. Which would have hidden the voltage drop prior to cutoff. You can generally hear the switching circuit put out RF noise if you hold it close to an AM radio. -Dave On Thu, 16 Apr 2015 09:04:01 -0600, Dan Marotta wrote: A comment on lithium batteries since I have two in my glider and a digital volt meter mounted on the panel... I don't notice much voltage drop as I did with lead batteries other than when I transmit. The data available for the batteries indicates a rapid decline and shutoff when the battery is nearly spent. I don't think that's a problem since the shutoff voltage is around 9.6 volts and your radio will quit transmitting before reaching that limit. The reason I post this is because I was using a lithium powered flashlight the other day while working on my car and, when the battery reached it's limit, it simply shut off. It was so sudden that I thought the bulb had burned out. No dimming as you're used to with standard batteries. Changing the bulb had no effect so I swapped batteries with my drill and the light worked again. Charging the battery took less than an hour. On 4/15/2015 11:27 PM, Paul Remde wrote: Hi, I just added some new batteries to my web site tonight. They have been highly recommended to me by several sailplane pilots. New - Bioenno Power Lithium Iron Phosphate LiFePO4 12V Glider Batteries - Enhanced cycle life - up to 2000 charge cycles! After 2000 charge cycles, the battery still holds 75-80% of its original capacity. - Lower weight - less than half the weight of lead-acid batteries! If you are accustomed to using lead-acid batteries - you will be shocked the first time you pick-up one of these batteries. - Constant and stable discharge voltage - Lead-acid batteries gradually lose voltage over time as they discharge - dropping below 12V early-on. LiFePO4 batteries have a much more gradual decrease in voltage until they are nearly fully discharged - staying at 13+V for most of their discharge cycle - so they are able to power your sailplane radio and instruments at higher voltages for longer periods of time. Higher voltages assure maximum transmit power from radios and transponders. http://www.cumulus-soaring.com/bioenno.htm Best Regards, Paul Remde Cumulus Soaring, Inc. -- Dan Marotta |
#8
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![]() Tom: I am curious how you have two batteries wired in the DUO? Parallel, two switches to a common bus? Inquiring minds want to know! Thanks |
#9
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Not Tom, but I have two LiFePO4 batteries with two toggle switches wired
to a common DC bus. Switchover is simple: raise the second switch, lower the first. On 4/18/2015 11:22 PM, wrote: Tom: I am curious how you have two batteries wired in the DUO? Parallel, two switches to a common bus? Inquiring minds want to know! Thanks -- Dan Marotta |
#10
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Thanks, Dan. There seems to be a plethora of over-thinking on this subject, but I could be wrong......
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