by Greg Covey
As we push the envelope of electric flight technology further, we learn from our mishaps how to improve things. In the past few years, we have learned that Lithium battery technology can be dangerous if not respected properly. By stressing our Lithium packs in applications that draw excessive current, create high temperatures, over-discharge, and over charge the cells, we have learned that this increases the damage to the pack, causes a risk of fire, and, decreases the lifespan of our usage from that pack which can be very costly.
Today's Lithium Power Solutions help to increase safety and longevity of Lithium battery packs. By automating charge current, fixing cell counts, and, monitoring each cell during both charge and discharge cycles, the Lithium Power Solutions available in today's market provide a safer application that is much more cost effective for R/C electric power.
In the Past - ESC LV Cutoff:
Until recently, Lithium packs were treated in a similar fashion to NiCd and NiMH packs during both charge and discharge cycles. They were treated at the pack voltage level and not the individual cell level. The Electronic Speed Controller (ESC) would monitor the pack voltage and shut the motor down when the voltage was reduced to a certain level. Over time, the ESCs became smarter and needed to see the low voltage level for a certain period of time before cutting off the motor, and, they also became Lithium-aware so that different cutoff voltages could be used to better suit each battery technology or flight performance.
The big shortcoming of this approach was for Lithium packs that had a weak cell or became unbalanced. By the time the low voltage cut-off was detected for the pack voltage, one or more cells may have been discharged too far.
Depending upon the cell manufacturing technology and charger design, a 3C charge rate is achievable for charging a pack to 90% full capacity in only 20 minutes!
When Lithium packs age, through handling or insertion stress into the plane, crashes, etc., the outer cells lose their capacity early. This can happen from small dents in the surface through rough handling, warping of the cells, or by tossing the packs back in your flight box. Further, the inner cells can be stressed by higher temperatures if the packs are pushed even to rated discharge limits for too long. The result is that each cell starts to have a slightly different capacity in the pack. By monitoring the cells during both charging and discharging, you can safely use the pack at the capacity of the weakest cell without further damage.
Other Criteria for Longevity:
The two most common criteria left for the user to maintain the health of their Lithium pack are discharge current levels and cell temperature. When treated properly, a Lithium pack can achieve 500 cycles before losing only 20% capacity. Lithium packs that have been stressed by over current draw, which creates high temperatures in the cells, have their lifespan reduced to 50 cycles or less.
How do we know the true cell limitations?
Cell Rating Spec.
As Lithium cells become more of a commodity, the Lithium Power Solutions will differentiate the pack performance and longevity. We'll see the same cells being sold by multiple vendors under different names (e.g. ThunderPower, Cellpro Slimline). The cell ratings will vary and a user must select the most trusted source of information.
The Cell Rating Spec. is the primary guideline for properly using LiPo cells and packs. The discharge curves below are based on a test of a statistically valid sample of production cells. All tests are performed at room temperature with no cooling to the cells so that all ratings are conservative.
There are four curves in the set that define cell rating:
Monitoring Lithium packs at the cell level during both charge and discharge cycles are needed to protect the weakest cell in the pack because they age independently due to handling and temperature stress. Cell level monitoring protects the longevity of your Lithium pack and your investment. Understanding true cell rating specifications from a trusted source empowers you to be aware of marketing hype.
Respectfully I think it is you who are confused Wholesale NFL Jerseys the terminology. That will certainly Cheap Jerseys From China even more eyebrows within the organization. A woman reporter tries to prove she's just as good as any , but runs into trouble along the way. Do you think Wholesale NFL Jerseys kid's not out there trying his ass off? Together with Jarvis Cheap NFL Jerseys the Miami Dolphins, it is our goal to inspire people to take interest learning about finances early on, said BankUnited President, Region M. Griffin is expected to start his place. With all of the offense and creativity, it would be nice to have a defensive duo that can be relied upon when is attempting to lock down a lead. If he is designated a post- 1 release, then the Cowboys can spread the cap hit over the next two seasons, which would save them $14 million cap space 2017.
ended up Cheap NFL Jerseys every position on the Oilers Titans offensive line, with 99 starts at Left Guard, 67 at Right Guard, 87 at Center, 22 at Right Tackle, 17 at Left Tackle. Please note that CBC does not endorse the opinions expressed comments.
Though he claims to be a bit of a hermit, Ramm spearheaded the L-12 gathering . They feel bad enough without us booing them. Take a look at the complete list of announced shows. Perhaps that's why Eagles tackle was the last getting dressed, taking his time as if he knows what's coming. No movie this Javon Hargrave Jersey but finished the 13-episode The Crown on Netflix. The offensive staff oversaw a top-eight running game. Ramsey's five passes defensed are the second-most the NFL 2016 Akiem Hicks Youth Jersey most by a rookie Authentic Jack Doyle Jersey 2013 when Milliner also registered five. By the time Flutie's debut was over, he completed only 7 of 18 passes, for a total of 174 yards, while running for only 51 yards.
It may be early into his Nets' Cam Fowler Womens Jersey but he needs to show us if he is really made up of Brooklyn Grit, or just another Deron . First why did Comey do it? And they Marcus Cannon Womens Jersey right to be worried.
On the pro side of keeping him, he is a very solid defensive end on a team that Chris Baker Youth Jersey needs defensive linemen. I have no problem giving Cuadras a rematch, but right now focus is on Sor Rungvisai who is mandatory for the WBC. What's next: Missouri's win against Arkansas means that Mizzou, not , play the SEC title Will Compton Youth Jersey next Saturday. He'll likely cost Kyle Emanuel Womens Jersey $9 million to $10 million per year if he's signed to a -term contract. The show was the brainchild of Hewitt, a producer who was bad odor at News at the time, Mr. And it was incredible. He was a 1953 graduate of the former Mount High School. I'm so proud of them. He Corey Brown Youth Jersey a longstanding friendship with Barkley.
How were you guys able to develop that chemistry Jack Butler Jersey has made your line successful? Terrance West was that draft.
I've played a lot of fours already far, and a lot of threes, too. Pittsburgh's Cheap Jerseys Sale of building a hockey team relies upon superstars with high cap hits and you have to have some viable depth players on cheaper contracts. You can follow the team links the chart above to locate common statistics , advanced statistics , and unique statistics not found on any other Wholesale Jerseys December 1986, Moseley, the NFL's last full-time Cheap NFL Jerseys kicker, made his final field goal as a member of the Browns. The Braves traded Murphy after fifteen seasons to the Philadelphia Phillies 1990. I was just happy for them to get the win, because our guys have worked really hard and suffered some really tough, close losses, Paulsen said. They have excellent core group of players. But at the same Cheap NFL Jerseys I've got to be excited right now. The fullback is a dying breed the NFL, but does he think he can bring it back? And, you know, there was the time she said Adolf Hitler wasn't bad. Twelve shots last game, not really forcing Cheap Jerseys issue offensively.
Grulks says: 6 11 AM It doesnt matter if Hackenberg can or cant make it the nfl. Wholesale NFL Jerseys school boys basketball W.C. Plouffe has spent his first seven MLB seasons with the Minnesota Twins, logging a .247 career batting average with a .727 OPS.
Jeter, who was retiring after the , doubled on Wainwright's second pitch of the game. Packers McCARTHY …Is his 11th year as the Packers' 14th head coach. Farmers are Connor Barth Youth Jersey forward to more rain to help their crops, while homeowners wildfire-damaged areas Authentic Russell Okung Jersey fearful of more mudslides. 25 - Hampton .
Cheapseats By Brennan, First posted: Tuesday, 26 11 PM EST | Updated: Tuesday, 26 11 PM EST Buffalo Sabres goalie Lehner celebrates his win over the Senators on . If the morality clause was intended to be about more than just steroid use, voters should consider using it as a reason for keeping Ramirez off their ballots. Kerney's house was never scoured for evidence. They got their payoff when Flores delivered important spot.