Hello All,
I have received 10 x 3S 11.1v 5AH Turnigy Lipo packs.
1 of 10 3S packs was DOA but repaired (I think, still have to test on bike)
Bottom Line: Extreme Power, No Heat, Great Price, Very Light - Awesome Packs, Tested, Measured and Confirmed, Very Low Internal Resistance !!!
I have never had a lipo fire but please take proper precautions and don't be a jacka$$, mounting your lipos under your crotch in the A frame without some form of NON flamable battery box with some form of pressure cap that faces either forward or is at the far forward position and vents right and left of head stem or at a minimum a blast shield.
My batt box (blast box) is made of 5mil alum panels, welded together which has right and left forward vents (hopefully wont melt or warp head stem if it ever blows a lipo) and will protect my crotch, legs, passenger (my son behind me) from flames, exhaust venting from a lipo puff or fire. Designed so that if there is any real force the directional thrust of the explosion / fire will cause the ebike to slow it's forward momentum.
I went the further step of rigging a very quick, one handed disconnect which will jetison the entire battery box.
This might be over engineered but I have seen the you tube videos of lipo fires / explosions and the added weight of the alum box is minor and should channel any burn out away from me and my son. The critical point is my son!
Once I finish the battery box (painted titanium to match the bike) and my pre-controller I will post all relevant details needed to diy the blast box (can't think of another name), the pre-controller and any other niceities I come up with in my experiments.
Current eBike is:
36" front hub kit from Jason @ http://www.e-bikekit.com of which I am using the included Infineon 9FET controller mounted to the bottom side of a front handlebar bag and the hub (I had to slightly taper the 10mm keyway in the axleshaft to fit in the dropouts properly of my Judy TT and now my Tora RockShox).
Inital power source: 36s3P nimh for 50.4v @ 9900mah charged (from Jason @ http://www.mtobattery.com, fantastic battery shop... found him dealing with Segway battery failure due to moisture, he laser cnc's the cases open this guy is battery elite)
In all fairness I should add that I have modified the controllers software using ParameterDesigner (and a USB->Serial TTL inteface from sparkfun that I had laying around from some previous project). My mods were to the LVC, Current Limit=38.5A, Phase Current Limit=75A, S2 Speed=110% and a few other tweaks (do a quick search on google or here at ES for "infineon controller Parameter Designer").
The results are spectacular (once my front wheel stops smoking - well spinning) TOP SPEED=38 MPH, AVG=32, Range on 5AH 12S (4x3S 5AH Turnigy Packs) approx. 6 MILES / 9.656064 KPH @ nearly WOT and NO pedaling (not even to help start). This was a brute range test at max power and let me say that my test course is not for the faint of heart, 1.2 mi of 50/50 flats and 10% grades, dh 30% grade, 3.1mi gradual 10%, 1.5mi with a nice .5mi 24% grade uphill and then a patch similar to the first 1.2mi with 50/50 flats and 10% grades.
With LVC set for 3.2v per cell or 38.4 (actually set lower but with 4v of slack, see the ParameterDesigner info) and according to my eLogger v3 the pack provided 5302mah (over rating even with such a safe cutout margin), peak current of 38.5 (dead on) and ear to ear ev grin accelleration, max watts was approx 1954 WATTS - lol, motor never got warm, esc was but batteries stayed about 2 deg. C over ambient temp under my approx 8C max continuous load.
I should also add that I charged and balanced these 3S packs 2-3 times before this test using iCharger 1010B+ and monitoring / logging all charging data for the packs using LogView. Charged they were all within .01mv of each other (in each 3S pack and paralleled into 12S) and stayed this way through 1C discharge testing.
Only issues with the Turnigy's was 1 of 10 came in at 0 V but a quick check on ES and in the HK comments for the packs and I tore the wrapping off the bad 3S pack and sure enough the solder joints had broken (weren't great to begin with) Since I had no aluminum rosin or solder I just used my trusty and overpowered RS gun to remeld the existing solder joint while applying pressure to the disconnected tab using a probe from and old VM (I do this alot).
Though I haven't discharged this repaired? pack on the bike yet, I have run it through 5 full charges at 1C (first charge I did at 1/5 C and dischage at 7A and pack seems fine. I will test on bike in a day or two and post any observations or issues with the pack keeping it ourside my battery box in a seperate lipo bag while testing for safety, and no I don't test with my son... I use 38lbs of SLAs and a 5gal gas can filled with water in the child seat to simulate my son and his shifting weight while testing)
If anyone would like the logs from the eLogger or the charge / discharge cycles on the packs from logview, drop me a msg and I will provide them.
Sorry for the long post but I did the full gamet of testing on these packs and thought I should share as much detail as possible.
Thanks to everyone for all their help, contributions and problem solving that got me interested in an eBike as an alternative to my i2 Segway (3 years and still going).
- Mike