can773

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Hey guys,

Thought I would share some data with you that I recently gathered on some of my packs.

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.

The files are .txt files, you will need to save as and rename the extension to .pdf to read them.

can773

My Feedback: (1)

Since saving and renaming is probably a pain in the arse, here are snapshots of the pdf's.

The pdf's are better quality but this should be good enough

woodie

Thanks Chad, that is good info and very promising that the packs (and cells) are holding up that well. I have around 50 cycles on my first (only) 5300 V2 and it continues to be my strongest pack from the middle of flight on to the end. I really like the minimal drop off in voltage. Based on my FAM CellPro 10S, IR has just barely increased. I am averaging around 4.4 mohm with less than .2 mohm delta. So far, so good!!!

Woodie (aka Don)

can773

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Hi Don,

Sounds like they are working good for you as well. I am quite impressed by them since they have not had any babying at all. I got them two days before the Nats started so they went into "serious use" right from day one

woodie

Chad, are you using 1C charging rate or have you gone higher? I still use the 1C rate due to that is near max on my chargers without splitting the packs.

Don

can773

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I can charge at 6.3A for a bit (it throttles down as the voltage comes up due to 240W limit) on my Schulze charger, and 1C on the 1010's.

KeithB

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can773

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Hi Keith I don't have any recent I flight data on that set of packs. I can grab that next time I am out flying. I will try and take some pics of the installation tonite and post them.

Scott Smith

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Here's one way...I wanted to be able to run the single 10S as well as thepair of 5300's sothe 5300 hardware is removable. The key to really locking in the batterieswas the top plate touching the fuselage sides (hence the two piece 'slider')

PatternFlyer

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Chad or anyone who has 53005SPL2,

the subject TP53005SPL2 is actually 5300mAh 5S2P. Am I right?

would you also verify the dimensions 41x68x104mm ??

Thanks!!

Ihncheol

Silent-AV8R

5S2P, a total of 2 5S packs, 10 2600 mAh cells

1.6 x 4.2 x 2.6 inches