If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
#31
|
|||
|
|||
K2 battery endurance
My Bioenno batteries worked just fine for several years.Â* Just sayin'...
On 6/2/2020 10:26 AM, Richard Pfiffner wrote: On Monday, June 1, 2020 at 9:46:09 PM UTC-7, kinsell wrote: On 5/25/20 9:47 PM, Eric Greenwell wrote: 2G wrote on 5/25/2020 2:20 PM: On Wednesday, May 13, 2020 at 8:00:09 PM UTC-7, kinsell wrote: ... The BMS in all LFPs may not have the same functionality regarding balancing but at the very least they should start/stop accepting charge appropriately. It matters not what you think should happen, the truth is not all LFP batteries have a BMS, and of those that do, not all of them protect from over and under voltage. Which LFP batteries don't have a BMS? Tom The "powersports" (ie, for engine starting) LFP don't always have a BMS. A motorglider pilot might be tempted to use one for the engine, for example. StarkPower had a series of batteries aimed at motorcycles that they were quite open about not having a BMS. Unfortunately they're in Chapter 7 now and the website is gone. More commonly, some batteries with BMS don't have over and under voltage protection. Richard Pfiffner one time was testing batteries, and his vendor shipped 24 volt chargers accidentally for 12 volt batteries. All the white stuff leaked out of the battery. Some electrical genius on R.A.S. (don't remember which one) declared that they really had overvoltage protection, but 24 volts just wasn't enough to trigger it. One of our fellow Schleicher motorglider pilots had an LFP, left the transponder on, and ruined the battery. A 15-20 AH battery intended as a starter battery can easily find it's way into other applications. You may have read about the ASG 32 mi that got fried when the solar controller malfunctioned, drained the battery, and got quite hot when charged from another charger. Did it have a BMS? Doesn't really matter. Dave The problem batteries were Bioenno Batteries. Richard -- Dan, 5J |
#32
|
|||
|
|||
K2 battery endurance
On Tuesday, June 2, 2020 at 2:10:54 PM UTC-4, Dan Marotta wrote:
My Bioenno batteries worked just fine for several years.Â* Just sayin'... On 6/2/2020 10:26 AM, Richard Pfiffner wrote: On Monday, June 1, 2020 at 9:46:09 PM UTC-7, kinsell wrote: On 5/25/20 9:47 PM, Eric Greenwell wrote: 2G wrote on 5/25/2020 2:20 PM: On Wednesday, May 13, 2020 at 8:00:09 PM UTC-7, kinsell wrote: ... The BMS in all LFPs may not have the same functionality regarding balancing but at the very least they should start/stop accepting charge appropriately. It matters not what you think should happen, the truth is not all LFP batteries have a BMS, and of those that do, not all of them protect from over and under voltage. Which LFP batteries don't have a BMS? Tom The "powersports" (ie, for engine starting) LFP don't always have a BMS. A motorglider pilot might be tempted to use one for the engine, for example. StarkPower had a series of batteries aimed at motorcycles that they were quite open about not having a BMS. Unfortunately they're in Chapter 7 now and the website is gone. More commonly, some batteries with BMS don't have over and under voltage protection. Richard Pfiffner one time was testing batteries, and his vendor shipped 24 volt chargers accidentally for 12 volt batteries. All the white stuff leaked out of the battery. Some electrical genius on R.A.S. (don't remember which one) declared that they really had overvoltage protection, but 24 volts just wasn't enough to trigger it. One of our fellow Schleicher motorglider pilots had an LFP, left the transponder on, and ruined the battery. A 15-20 AH battery intended as a starter battery can easily find it's way into other applications. You may have read about the ASG 32 mi that got fried when the solar controller malfunctioned, drained the battery, and got quite hot when charged from another charger. Did it have a BMS? Doesn't really matter. Dave The problem batteries were Bioenno Batteries. Richard -- Dan, 5J The BMS boards must be changing over the years. I don't expect a company like Bioenno could keep getting the same model BMS over time, even if they tried. Not at a reasonable price anyway. You just get whatever is being churned out in large numbers by a few Chinese factories at the moment. If you want to know whether your specific battery has overvoltage cutoff, try it! Connect to a source with about 15-18 volts, via a resistor to limit the current, and watch the voltage on the battery. It should eventually drop (when cut off at something less than 15V if it's a "12V" LFP), and then the voltage on the resistor should drop to zero (no current). A smart charger such as the iMax B6 can serve for the test, tell it the battery has 5 LFP cells in series ("15V" battery), limit the current to 0.1A, and watch what happens. Last year I bought an "energized outside" brand (since renamed) LFP battery.. When I charge it with my B6 smart charger, the BMS cuts out at about 14.4V, a bit earlier than the B6 would stop the charge at about 14.6V. As a result, the B6 yells at me about the battery being disconnected, and I can't see what the total amphours charge was. Minor annoyance. At least I know that that battery has a high-voltage cutoff. And another LFP battery I recently bought, PowerSync brand, shuts itself off when it tries to start up the motor in an electric mower I am using it in.. (Actually two 12V batteries in series.) The initial current surge is somewhat over the 20 amps peak that this battery allows. I solved that problem by adding a longish spool of wire in series with the motor to serve as extra resistance (0.3 ohms) to limit that current surge. And now I know that that BMS really does have an over-current shut-off. |
#33
|
|||
|
|||
K2 battery endurance
On Tuesday, June 2, 2020 at 1:10:54 PM UTC-5, Dan Marotta wrote:
My Bioenno batteries worked just fine for several years.Â* Just sayin'... I'm with Dan. I'm running Bioenno batteries and am very happy with them. 2 are 4 years old and work like new. YMMV - Lou |
#34
|
|||
|
|||
K2 battery endurance
On Tuesday, June 2, 2020 at 10:09:21 AM UTC-7, Eric Greenwell wrote:
Richard Pfiffner wrote on 6/2/2020 9:26 AM: ... StarkPower had a series of batteries aimed at motorcycles that they were quite open about not having a BMS. Unfortunately they're in Chapter 7 now and the website is gone. More commonly, some batteries with BMS don't have over and under voltage protection. Richard Pfiffner one time was testing batteries, and his vendor shipped 24 volt chargers accidentally for 12 volt batteries. All the white stuff leaked out of the battery. Some electrical genius on R.A.S. (don't remember which one) declared that they really had overvoltage protection, but 24 volts just wasn't enough to trigger it. One of our fellow Schleicher motorglider pilots had an LFP, left the transponder on, and ruined the battery. A 15-20 AH battery intended as a starter battery can easily find it's way into other applications. You may have read about the ASG 32 mi that got fried when the solar controller malfunctioned, drained the battery, and got quite hot when charged from another charger. Did it have a BMS? Doesn't really matter. Dave The problem batteries were Bioenno Batteries. Were they Bioennos with a BMS that protects against overvoltage? For example, I use the BLF-1220AS, which .... "Includes built-in PCM (protection circuit module) which provides internal cell balancing and management, protection from overcurrent, undervoltage (overdischarge), overvoltage and short circuiting, and has integrated charging circuitry " I haven't tried applying 24 volts to it, but I'd expect it to protect against 24 VDC being applied to it. I've just emailed Bioenno this question, but have not heard back. -- Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me) - "A Guide to Self-Launching Sailplane Operation" https://sites.google.com/site/motorg...ad-the-guide-1 Eric, I don't know about the BMS. All I know is Bioenno supplied the batteries with a 24 volt charger. When the batteries were charged they were destroyed. Bioenno replaced the batteries and chargers although it took a long time to get the replacements. Richard |
#35
|
|||
|
|||
K2 battery endurance
Richard Pfiffner wrote on 6/3/2020 5:35 AM:
On Tuesday, June 2, 2020 at 10:09:21 AM UTC-7, Eric Greenwell wrote: Richard Pfiffner wrote on 6/2/2020 9:26 AM: ... StarkPower had a series of batteries aimed at motorcycles that they were quite open about not having a BMS. Unfortunately they're in Chapter 7 now and the website is gone. More commonly, some batteries with BMS don't have over and under voltage protection. Richard Pfiffner one time was testing batteries, and his vendor shipped 24 volt chargers accidentally for 12 volt batteries. All the white stuff leaked out of the battery. Some electrical genius on R.A.S. (don't remember which one) declared that they really had overvoltage protection, but 24 volts just wasn't enough to trigger it. One of our fellow Schleicher motorglider pilots had an LFP, left the transponder on, and ruined the battery. A 15-20 AH battery intended as a starter battery can easily find it's way into other applications. You may have read about the ASG 32 mi that got fried when the solar controller malfunctioned, drained the battery, and got quite hot when charged from another charger. Did it have a BMS? Doesn't really matter. Dave The problem batteries were Bioenno Batteries. Were they Bioennos with a BMS that protects against overvoltage? For example, I use the BLF-1220AS, which .... "Includes built-in PCM (protection circuit module) which provides internal cell balancing and management, protection from overcurrent, undervoltage (overdischarge), overvoltage and short circuiting, and has integrated charging circuitry " I haven't tried applying 24 volts to it, but I'd expect it to protect against 24 VDC being applied to it. I've just emailed Bioenno this question, but have not heard back. Eric, I don't know about the BMS. All I know is Bioenno supplied the batteries with a 24 volt charger. When the batteries were charged they were destroyed. Bioenno replaced the batteries and chargers although it took a long time to get the replacements. Richard I emailed this question to Bioenno: "Does the BLF-1220AS protect itself if a charger for a 24 volt Bioenno is connected to it?" Their answer: "The BLF-1220AS can only accept a charging voltage from 13.8VDC to 15.3VDC. If you exceed 15.3VDC, the BMS will trip and the battery shuts off. However, high voltage should not be left attached continuously to the battery which can cause permanent damage to the BMS/cells. If the voltage is less than 13.8VDC, the battery will charge, but not be 100% charged. -Kevin" I don't consider 24 volts (or the likely charging voltage of 28 volts) to be a "high voltage", but it sounds like leaving a 24 volt charger applied to a 12 volt Bioenno battery will damage the battery after a while. So, while the battery does protect itself in the short term, neither the battery nor the charger indicate that there is a problem. Since the battery can be hidden from view, I think the charger should be smart enough to indicate it's been connected to the wrong battery AND it should disconnect itself. The Bioenno charger does neither, unfortunately. If you do connect the 24 volt charger to the 12 volt battery, the LED indicator (all it has) will show GREEN, indicating the battery is fully charged, instead of RED, your expectation to indicate it is charging. Too subtle, I think. -- Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me) - "A Guide to Self-Launching Sailplane Operation" https://sites.google.com/site/motorg...ad-the-guide-1 |
#36
|
|||
|
|||
K2 battery endurance
On Wednesday, June 3, 2020 at 9:12:00 AM UTC-4, Eric Greenwell wrote:
Richard Pfiffner wrote on 6/3/2020 5:35 AM: On Tuesday, June 2, 2020 at 10:09:21 AM UTC-7, Eric Greenwell wrote: Richard Pfiffner wrote on 6/2/2020 9:26 AM: ... StarkPower had a series of batteries aimed at motorcycles that they were quite open about not having a BMS. Unfortunately they're in Chapter 7 now and the website is gone. More commonly, some batteries with BMS don't have over and under voltage protection. Richard Pfiffner one time was testing batteries, and his vendor shipped 24 volt chargers accidentally for 12 volt batteries. All the white stuff leaked out of the battery. Some electrical genius on R.A.S. (don't remember which one) declared that they really had overvoltage protection, but 24 volts just wasn't enough to trigger it. |
#38
|
|||
|
|||
K2 battery endurance
I have recently moved from my still good, 8 year old K2 to the rated 9 amp version of these PowerSonic Iron Phosphate batteries:
https://www.power-sonic.com/batterie...etooth-series/ I am very happy with it so far. My tester shows that at a 1 amp discharge rate I'm getting 10.3 Amp Hours. The battery has over/under voltage protection although I have not tested the feature. The app (Android only) is very useful providing SOC, voltage, current measurement in/out, number of discharge cycles, individual cell voltage readings, and battery use event errors (over/under voltage, etc.) It works great. I am able to insure that starting the flight I'm at 100% SOC (well, 99% because I know that my charger slightly undercharges.) After 5 hours of use I'm down to 60% very consistently. The Bluetooth system is TI-based and I believe that the BMU is also TI-based. It is a tremendous value for what you get. Danny Brotto |
#39
|
|||
|
|||
K2 battery endurance
On 6/3/20 2:12 PM, Eric Greenwell wrote:
wrote on 6/3/2020 12:06 PM: On Wednesday, June 3, 2020 at 9:12:00 AM UTC-4, Eric Greenwell wrote: Richard Pfiffner wrote on 6/3/2020 5:35 AM: On Tuesday, June 2, 2020 at 10:09:21 AM UTC-7, Eric Greenwell wrote: Richard Pfiffner wrote on 6/2/2020 9:26 AM: ... StarkPower had a series of batteries aimed at motorcycles that they were quite open about not having a BMS.Â* Unfortunately they're in Chapter 7 now and the website is gone. More commonly, some batteries with BMS don't have over and under voltage protection.Â* Richard Pfiffner one time was testing batteries, and his vendor shipped 24 volt chargers accidentally for 12 volt batteries.Â* All the white stuff leaked out of the battery.Â* Some electrical genius on R.A.S. (don't remember which one) declared that they really had overvoltage protection, but 24 volts just wasn't enough to trigger it. One of our fellow Schleicher motorglider pilots had an LFP, left the transponder on, and ruined the battery.Â* A 15-20 AH battery intended as a starter battery can easily find it's way into other applications.Â* You may have read about the ASG 32 mi that got fried when the solar controller malfunctioned, drained the battery, and got quite hot when charged from another charger.Â* Did it have a BMS?Â* Doesn't really matter. Dave The problem batteries were Bioenno Batteries. Were they Bioennos with a BMS that protects against overvoltage? For example, I use the BLF-1220AS, which .... "Includes built-in PCM (protection circuit module) which provides internal cell balancing and management, protection from overcurrent, undervoltage (overdischarge), overvoltage and short circuiting, and has integrated charging circuitry " I haven't tried applying 24 volts to it, but I'd expect it to protect against 24 VDC being applied to it. I've just emailed Bioenno this question, but have not heard back. Eric, I don't know about the BMS.Â* All I know is Bioenno supplied the batteries with a 24 volt charger. When the batteries were charged they were destroyed.Â* Bioenno replaced the batteries and chargers although it took a long time to get the replacements. Richard I emailed this question to Bioenno: "Does the BLF-1220AS protect itself if a charger for a 24 volt Bioenno is connected to it?" Their answer: "The BLF-1220AS can only accept a charging voltage from 13.8VDC to 15.3VDC.Â* If you exceed 15.3VDC, the BMS will trip and the battery shuts off. However, high voltage should not be left attached continuously to the battery which can cause permanent damage to the BMS/cells.Â* If the voltage is less than 13.8VDC, the battery will charge, but not be 100% charged. -Kevin" I don't consider 24 volts (or the likely charging voltage of 28 volts) to be a "high voltage", but it sounds like leaving a 24 volt charger applied to a 12 volt Bioenno battery will damage the battery after a while. So, while the battery does protect itself in the short term, neither the battery nor the charger indicate that there is a problem. Since the battery can be hidden from view, I think the charger should be smart enough to indicate it's been connected to the wrong battery AND it should disconnect itself. The Bioenno charger does neither, unfortunately. If you do connect the 24 volt charger to the 12 volt battery, the LED indicator (all it has) will show GREEN, indicating the battery is fully charged, instead of RED, your expectation to indicate it is charging. Too subtle, I think. -- Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me) - "A Guide to Self-Launching Sailplane Operation" https://sites.google.com/site/motorg...ad-the-guide-1 The battery does not "know" that it is connected to a 24V charger. The battery itself should clamp the voltage to a value consistent with it's state-of-charge. If a 24V charger is able to deliver current at the relatively low voltage of the 12V battery, then current will flow and the battery will absorb this current, charge, and reach the BMS cutoff voltage at which time the overcharge protection FET should open. The voltage across the battery terminals will then be 24V but with no current flow since the FET is open. The internal battery cell cluster will not "see" this high voltage but portions of the BMS circuit will. This 24V "may" damage the BMS if it is not rated for it. There may be some small leakage current through the overcharge FET which may get through to the inner cell cluster which, over a (very, very) long period of time, damage the cells. Danny Brotto Perhaps I wasn't clear. I want to the battery to have an LED indicator that announces it has shut off the battery due to an overvoltage. And definitely shut off - not clamp the voltage. It doesn't matter what is supplying the high voltage. I also want the 24 volt battery charger to shut off it's output if it doesn't detect a 24 volt battery on it's output, and have an LED indicator to show that's why it shut off. I very much do not want a 24 volt charger to attempt charging anything but a 24 volt battery. My first priority would be to have an overvoltage circuit that performs as you would reasonably expect it to, along with clear specs such as "withstands 50 volt continuous voltage on the terminals with no damage" and "withstands 20 volt reverse voltage on the terminals". Many smart chargers will refuse to try to charge a backwards connected battery, but not all of them. EaarthX makes LFP's for experimental and certified aircraft, and they do have an error output that drives an LED and/or an EFIS system to warn of problems like a weak cell. They require that this info be provided to the pilot in flight. I was a little confused by Danny's answer, he seems to be confusing how he thinks the Bioenno batteries should work, rather than how they actually DO work. This after the vendor confirmed they can't withstand continuous overvoltage, and Richard dramatically demonstrated the problem on a number of units. Fortunately Richard does 100% incoming inspection on his batteries, and was able to catch the issue. Doesn't speak well to the vendor's quality control. Maybe not as bad as sprinkling metal shavings in the lithium-cobalt batteries, but still not good. -Dave |
#40
|
|||
|
|||
K2 battery endurance
Dave,
The Bioenno site shows this 14.6V 2A charger to be the one recommended on their web site. I suspect the supplied 24V chargers were a QC issue in pack out; somebody packed 24V chargers with 12V batteries. Bioenno also sells 24V packs with a compatable charger. https://www.bioennopower.com/collect...-to-dc-charger Danny Brotto |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
NY Kart Endurance Challenge 3 Hour Race - Arrive & Drive | OVRPNY | Piloting | 0 | June 9th 05 11:18 PM |
NY Kart Endurance 3 Hour Challenge Race - Arrive & Drive | OVRPNY | Owning | 0 | June 9th 05 11:17 PM |
NY Go Kart Endurance Racing - Arrive & Drive - No Experience Needed | OVRPNY | Owning | 1 | May 19th 05 04:56 PM |
NY Go Kart Endurance Racing - Arrive & Drive - No Experience Needed | OVRPNY | Piloting | 0 | May 19th 05 02:01 AM |
Speeds for best range or endurance don't depend on altitude | John T Lowry | Piloting | 5 | April 16th 04 02:02 AM |