Battery Performance

[Jef Ott]

Hi Guys.Peter Sainsbury was asking for hints and tips on improving the climb rate on his Simply the Best (I think) electric model, at the Bartletts comp on Sunday. (I think he said it would only achieve 150m in 30seconds, so that would mean he is looking for a 35% improvement.)I suggested that instead of changing the motor / gearbox /esc etc. which would be complicated by the model's very slender nose, simply finding a similar nominal voltage battery pack with lower internal resistance may be Simply the Best option (there might be a pun there if his glider really is an StB).Experience with GiantCod's Loong Max Tipple series of LiPos had been good for my model's performance, but other people mentioned different makes that were even better at maintaining their voltage throughout the climb.Peter connected one of my LM Tipple 800mAh packs and saw an improvement of at least 20% over his Lemon R/C 1000mAh pack, when tested at full throttle with the model held stationery. This was despite a string of battery connection adapters as long as a baby's arm, to convert from 3.5mm Male to 3.5mm Female and vice versa (between the battery pack and the Wattmeter). Perhaps a larger capacity Loong Max Tipple pack (say 1200mAh) would make the extra difference... of course a larger prop is the next step (if the ESC can take it), and there is always cell heating as an additional option (ambient temp was 14.5 degC).Of the other manufacturers mentioned, I think Thunder Tiger were stated as being even better performers... what are your findings? Best regards,Jef

[Dave C]

Jef,I have to agree with you regarding Loong Max Tipple lipo's.My 2.5M Bingo (e-glider) has a Kontronic 480-28 motor + 5.2:1 g/box and was flying with a Thunderpower 2200 Extreem V2 25C/50C 3S battery, and giving what I thought was a very acceptable climb rate.  The battery had only been charged about ten times – always at 1 amp and through a balancer – and had never been over discharged. I bought a LM Tipple 2300 25C 3S from G/Cod – for another model - but I tried it in the Bingo first to get some kind of comparison with the Thunderpower.  The figures using Aeronaut 16x8 folding blades were:Thunderpower – 30Amps/300Watts/10Volts/4600RPMLM Tipple – 43Amps/480Watts/11.16Volts/5400RPMI could hardly believe the difference and so I repeated the checks and got:Thunderpower – 33Amps/316Watts/9.57Volts/4600RPM   (Battery was probably warmed up by first test)LM Tipple – 42Amps/470Watts/11.16Volts/5300RPMAs a result of this, the Tipple stayed in the Bingo, giving it a much improved rate of climb, and the T/power was relegated to a 'less demanding' roll.Even better – the Loong Max cost me, if my memory serves me well, only about half of what the Thunderpower did.Dave.

[Jef Ott]

Thank you Dave!Excellent data.My Reichard Rapid was a bit sedate compared with other height limiter gliders, so I upgraded from Dualsky XPower cells to a nearly new non-Tipple Loong Max, this meant getting a good 36A from the setup, a big improvement on the 27A previously noted on the same prop and gearbox combo.The climb was still marginal in cold weather, but on a warm day I could just get the height within 30 seconds.I decided for the same reason as you (another model needed a battery) to get a Loong Max Tipple 25C 2300mAh, and that gave the same model setup a peak draw of 50A!Cheers,Jef

[EssexBOF]

Much of what has been said is spot on with regards to Loong Max. I have used them for some time now in preference to other cells. Peter Hindle has had 2 packs that have been faulty on delivery with 1 cell in the 3 being dead( nogood sending them back as GC does not want to know, not sure how he get away with that under the Trade Descriptions act). A couple of these packs have swollen or puffed up whatever, but still give out the power but became more difficult to fit into model.Basically these cells have a lower internal resistance over the other lower performing cells, but will the higher ones last longer?I have Kokam cells that are over 5 years old that still balance & charge up OK, but do not give out as much power.Use Overlander Extreme in the Stork as the current draw is high, so the 60C rating is a bonus The Hyperion cells also seem good.

[Jef Ott]

At the Bartletts Comp on June 19th, Peter Sainsbury made a point of coming to see me and presented some data which confirmed that the StB setup benefitted substantially from a Loong Max Tipple battery in static tests.The static wattages with his previous 1000mAh 3-cell packs were 130W and 140W peak.The same capacity LM Tipple pack gave 180W.Pete had not flown the model at the time, as the wind strength had been too great to test a new setup comfortably, but the wattage increase is between 29% and 38%, so I reckon that the launch height should get taken up to 200m, in most conditions, without any problem (from the 165m achieved on the old packs).165m x 1.28% = 211mLet's hope the maths theory is proven with practice. Changing a battery pack is a lot less stressful on the pocket and brain than a motor / motor and gearbox change in the StB's slender nose. Jef