pattratt

My Feedback: (1)

Hey All
I really hate having to stand in 100 degree heat and fly around in circles breaking -in batteries so I decided to see what I had laying around in the shop to build a stand that would allow me to monitor the discharge current and at the same time keep the batteries cool during the process. The stand consists of a board, BVM 5" Fan assembly with CC 110 HV esc mounted in fan pod, Watt meter for battery monitor, 930 mah lipo & Duralite switch/regulator for Rx power, Hangar 9 meter to monitor Rx power, and an old 14 MZ RX that I never use. I just completed breaking-in two complete 10S F3A Unlimitted packs in one afternoon session. That's a total of 10 cycles dischared at 25 amps for a total of 2500 mah per cycle. There is so much cooling air that the batteries never get over ambient temp. It works great and really makes the process more accurate and much quicker! I programmed a seperate model in my Tx to set up the radio to provide 25 amps at full throttle and used left slider as a idle trim to slowly reduce power and keep motor cool. Only negative is the noise requiring ear plugs. If anyone has any questions I will try and answer them.
Dick

wagen017

Dick, I don't see any need to break in a battery for pattern flying. Nowadays the minimum C rating is 20 or higher so the pack is capable of much higher Amps then we ask for.

Anyway, just my thoughts. I welcome any other!!

Volkert

pattratt

My Feedback: (1)

Hey Volkert
F3A requires break-in for warranty purpose. He has already replaced one pack (2 sticks) as I followed his break-in procedure.

wagen017

OK. What is the break-in and how do they check??

Volkert

Chris Moon

My Feedback: (8)

Hi Dick, nice job on the set up.

Volkert, Li-po packs will absolutely work better and last longer with a break in procedure. Most people will use 3-5 cycles of at most 5C discharge for about 50% of the pack capacity at most. If you chart the data, you will see that during these cycles, the internal resistance numbers will go down and the power delivered will increase and then stabilize after 3-5 cycles and be ready for normal use. If you just plug a new pack in and go full power flying to 80% discharge, it will certainly be damaged perhaps only slightly but you will get shorter cycle life than with proper break in. The problem is that you may not get any notice immediately that you have damaged the new packs, the results will show up later unless you hit them very hard and you can puff and destroy a new pack on it's first cycle. This is true for all brands. I have used lots and lots of brands for testing batteries and F3A Unlimited has sold many, many hundreds of Power Unlimited F3A batteries and the break in benefits are real.

wagen017

good to know, thanks!

Volkert

viva_peru

Neat idea. An alternative is to use automotive light bulbs hooked in series/parallel handle the voltage of the packs (determines the number in series) and the load (how many in parallel). Model aviation had an article a few years back. Not as cool however.

Teo

pattratt

My Feedback: (1)

Teo
I thought about that but there is two issues:
1. No way to keep a constant 25 amps without esc
2. No built in way to keep batteries cool
Dick

nonstoprc

My Feedback: (90)

One probably can replace th fan unit with a 10s rated motor mounted with a proper prop, or do it directly on the plane on the ground that has an outer run motor. Extra cooling can be provided by a fan.

I like the idea of the break-in stand.