Performance Data from Thunder Power's new 5300 Pro Lite batteries
Thanks to Chad Northeast !!!
(his notes go with the charts)
***UPDATED INFO 5/13/2009***
Background
New pack - approx 10-15 cycles, built in Feb. 2009
Old pack - approx 80 cycles, build in July 2008. I used this pack from the 2008
US Nats to present.
- Always recharged hot, I only take two packs to the field, so they come out of
the plane and I use fans to cool them down faster while charging, but they start
the charge hot
- Discharge is typically around 3500-4000 mAh, rarely higher. This pack was
discharged extremely deep one time, to around 3.2V resting...yikes!
- Peak draw has been mostly 70-75A in flight, I did run a prop that was pulling
around 85A for approximately 10 flights, during that time the discharge was
usually in the 4000-4500 mAh range
- Pack was stored over winter at 3.85 V/cell in the fridge
Plots
Two graphs attached, pretty self explanatory.
Data is taken using a Schulze 7.36-12 Next Generation charger discharging at 5A
down to 3.2v on the lowest cell. Each cell is monitored for voltage through the
balance leads, but the
balancer is not
active during the discharge.
One is the overlay of the new pack on the old pack, through approx 3300 mAh
discharge the packs are virtually identical in performance. Near the end of the
cycle you can see the change in the
batteries, there is
approximately 0.05V/cell drop on the old pack, or 0.5V across the entire 10s
battery. This
should translate to a minimal reduction in performance in flight, which is
essentially what I feel that the batteries are identical.
Second plot shows all the cell voltages during the discharge of the old battery,
it can be seen that they remain in a very tight formation, to me that shows a
good matching of the cells and fairly equal aging.
My plan is continue for another month or so, and redo this test to generate a
further plot showing degradation and try to predict lifespan.
Click on thumbnails to view graphs
Here are some files, The "prop compare" file is self explanatory, the 5200's in those plots have about 40 cycles on them.
For reference RPM's on these props on the 30-10 Evo, APC 21-14 - 6000/6100 Rasa 21x15 - 6400/6500 Rasa 20.2x16 - 6200/6300
(Click on graphs for larger pictures)
The other file is like this 1st graph is the voltage of a the first cycle of a two brand new sets of 5000 v2's
_small.JPG)
2nd graph, the two left most plots are of the first cycle of each of my
two sets of 5200's, and the right most graph is of a 25 cycle set of
5000 v2's to show the difference in voltage..JPG)
_small.JPG)
Load during flight is almost always the same during my flights between
65-75A, so I don't usually look at amps, just voltage. All P-09 rounds.
You can see the 5200's are very strong, holding over 35V under load when
new and even after 40 cycles only dipping below that on the last
maneuver. They seem to behave like the 5300 Prolites, but more power
and run much cooler not often going over 125-130F unless you run them
deep. So I am hopeful that with the extra voltage they hold they will
have a longer useful cycle life. To me they feel as strong as the 5000
V2's but without any dropoff near the end of the flight which I felt
with the V2's.
Pack weight is about 1180g give or take depending on your connectors
etc. Cost will be $250 per 5s set, so about $500 for a set of pack.
Its not clear at this time if a 10s set will be produced.
Hope that makes sense, feel free to post my comments as well.
Chad
.JPG)