This month a map showing the locations of local hospitals is included in the newsletter.  The three closest hospitals are Unity in Fridley, Mercy in Coon Rapids and Fairview in Wyoming, just north of Forest Lake.  So far it looks as though Fairview is the easiest to get to and the emergency room is open 24 hours.  Go east on Hwy 22 to Hwy 61, which is just a ways beyond Hwy 35, and south on Hwy 61 to the hospital, which is on the right side of 61 as you are going south.  The other hospitals are about the same distance but there are a lot more stop lights and stop signs. FLY SAFELY!!!!!!!

     So far ACRC has 14 new members for 2007.  Their names are listed below.  Some of them are first year fliers.  Please give them all the assistance that you can when you see them at the field.

     Paul Brand                 David Greene
     Gary Breitenbach       Dana King
     Steve Burmeister       Scott McCarthy
     Joseph Coleman         Stan Meyer
     Michael Davis            Alex Perez
     Vong Duong               Dan Thiede
     Zachary Geragi           Gary Titus

     The 2007 Pattern, Fun Scale and Scalemasters contests, along with the Float Fly, are now history.  The only event still to occur this year, other than Fun-Flies, is the ACRC Electric Fly on September 8.

ELECTRIC FLY
     The ACRC Electric Fly will be September 8 this year.  Kevin Carlson is in charge and flying starts at 8:00 AM.

     The next meeting will be at the field on August 16 at 7:00 PM.  This is the last meeting at the field for 2007.  THE SEPTEMBER MEETING WILL BE AT RIVERWIND.  There will be a fun-fly on Saturday August 18.
                                                                       Stan Zdon

     "How should I store my batteries at the end of the season?  What should I do to them when I put them back in operation?"  The batteries should be removed from the transmitter and plane for longer-term storage.  Here in the south where a lot of us work out of our garage workshops I recommend putting them in the refrigerator (not the freezer) during the

off-season.  Why?  The failure mode of Ni-Cds is separator failure; this is the material that keeps the plates from touching each other.  When it fails the cell shorts.  At higher temperatures it oxidizes faster.  In fact, the rate doubles for every 10⁰ Celsius increase.

     "Should I store my batteries charged or discharged?"  It doesn't really matter; they will self discharge in a few months stored at room temperature.  If you are going to store them in the refrigerator the charge will remain for a lot longer so I would discharge them first to 4.4 volts and them put them away.  Good cells will just set there in the discharged condition (the voltage can vary considerably but is usually above 1 volt).  In a battery with damaged "worn out" separators in the cells, the cells are apt to short if left in a discharged condition.  This is actually good since it is the first indication of a cell that's going bad and it is best to replace the pack.  Batteries left on trickle charge will seldom short out since it is in the charged condition and any short that tries to develop will be zapped by the charge in the cell.  Partial shorts, those having fairly high resistance, can be developing that can cause the cells to self discharge at a higher rate than normal and possibly leave you short in the middle of a flight after you just measured the cell when it came off charge with your ESV and everything looked OK.

     Now when your batteries are coming out of storage, before charging, check the voltage without a load on the battery.  It should read well over 4.0 volts even if it has not been charged all winter.  They should be essentially fully discharged, flat as we say in the business.  In this condition if the battery is going bad it will probably have shorted and you will read zero volts on that cell.  It may be a soft short, one that could be blown away merely by the simple action of slow charging.  Don't do it!  It is just lying there waiting to bite you.  Replace the pack.  Cut out the "good" cells if you want and use them in something less critical than your model.  If you have access to a cycler, running though a couple of charge/discharge cycles is a good idea just to make sure you are getting the capacity you are suppose to.  Anything less than 80% of rated is suspect.  Once at the field, pre-flight battery checks are in order, particularly at the beginning of the season.  Since those that religiously check their flight packs with an expanded scale voltmeter seem to crash less (due to battery failure) one must assume that the ritual is smiled upon by the R/C Gods.

                                                  C. L "Red" Scholefield