Keeping a battery/flight log

What is a battery/flight log?
A battery or flight log is simply a written log containing various information about your batteries and or flights. This information can be as simple as the counting the number of cycles or can be expanded to include information about the flight, weather and anything else you might find useful at a later date.

Why keep a log?

Everybody has their own reasons but I personally like to keep a log for many reasons but mostly so I can keep track of the number of flights on each pack and each heli. You could for example calculate the cost per flight on your packs to decide if they were worth the money. Or you could keep the log the internal resistance of the packs to monitor their health. Your log info may also help with warranty replacements. Really I believe it simply comes down to the concept "information is power", so why not?

What info should be in the log?
That is totally up to each pilot. Some like to make their logs very complicated while others simply keep track of the number of cycles on each pack. It really takes time to decide what info to keep and so logs often change over time. I know my log started out fairly complicated and has slowly been trimmed down to just a few logged items.

Now for some log suggestions
Now that you know what a battery/flight log is, it's time for a few suggestions that will hopefully help you get one setup and help you stick with it. In short I am going to explain my experiences with making and refining my log.

Digital or paper?
I use both forms for my battery log. I keep a pad of paper with my charger and then later I transfer the info to an spreadsheet I keep. That gives me the best of both worlds, easy access to the paper log anywhere, anytime and then spreadsheet calculations when I want them.

Were I started information wise
I started my original log as a battery log so I made note of the date of each discharge, mAh replaced after charging and a little more info about the packs like temp after the flight and such. Later I started to care less about mAh replaced and more about flight info, so my log made its first change. I added a notes column for keeping info about my helis as well as flight notes.

As time went on I continued to make changes until after about a year of trying things, I found what works for me. Below is the log I currently use and have used for well over a year now. It houses the info I would like to have long term including battery cycle count, heli flight count and notes.

Useful long term data
I have talked to many people on this subject and I have found that no 2 people do it the same. Many could care less and simply fly. Others are very thorough, maybe too thorough if you ask me, and keep tons of data. Here are the items that might be handy long term.

Battery info
  • Flight/discharge date
  • Charge date
  • Battery cycle count
  • mAh replaced during charge
  • Battery IR (internal resistance)
Heli info
  • Heli flight count
  • Heli changes (mechanical, electrical and radio changes)
  • Heli maintenance (oiling, bearing replacement, etc)
  • Crash info (tracking damage and maybe cost)
In conclusion
Keeping a log of basic events which surround your rc heli can be a very handy took for many reasons. Some use it as a bragging tool and others do it just for themselves. What many find out is that it is also handy in warranty replacements and even aiding troubleshooting. Whatever the reason consider making a log for your batteries/helis, you might find out just how handy this information can be.