I tend to take more batteries than I need to the field when I go flying.  The benefits of having a four port battery charger, it's just as easy to charge four as one.  Both my chargers the single port and four port, have a storage feature and with some batteries it works great and with others it times out with the battery only down to 70%.  Since I don't like to store with more than 50% in the battery I have to run a second cycle to get it down.  This begs the question why?  The setup on the both chargers indicates the ability to set the discharge current rate, but neither will allow any change from the default setting.  What am I doing wrong? 
Andy

You are probably trying to set the discharge rate to something greater than the charger will allow.  Just like you can't set the charge rate to a greater value than the charger will allow.  On my little Turnigy 50 watt chargers, the MAX discharge rate is only 5 watts, so for a 4 cell battery, something like 300 ma.  Not terribly useful.  In order to get batteries down to 50%, it is much easier for me to give them a partial run and then put them on 'Storage' mode charge.

Which charger do you have?  I THINK I can turn my 'time-out' feature off, but have never looked to be sure.  It would still take too long to run them down to 50%, so I just don't use that feature.

Andy

Sky RC iMax chargers are the same as the Hitecs.  

Dan

What I don't get is the operation manual says the discharge rate is adjustable, but it cannot be changed from the default setting of .1 amps (100mha) which to me is really low.  If I am discharging a 3300mha battery I would like to discharge at a minimum of 1 amp hour rate at least until the charger detects it is nearing the end of the cycle.  
Andy

My cheep charger is about the same.  In the discharge mode you are dumping the current through a resister and generating heat. At 1 amp it would be 11 watts of heat for a 3 cell pack.  That takes more than you think to cool.  The 1 watt for the .1 amp is more like it.  The deal is that in the charge mode the charger is fairly efficient.  That 50 watts of energy that the charger dilevers is being absorbed by the battery to convert the chemicals in the battery to the high state (ie charged). Almost no energy is lost in charger and the charger heats very little.   In the discharge mode all the energy is converted to heat in the charger.  That is why in a cheep charger the discharge rate is always much - much less than the charge rate.  For this reason it is best to charge a dead pack to the storage level rather than trying to discharge a fully charged pack down to the storage level.  What I do is slap a charged pack in the airplane and run it for 3 minutes or so - then charge it to storage level.   Rig a tiedown for the aircraft and you don't even have to hold it.

 

Of course another obvious solution is to get a charger that will allow you to discharge your packs at 3-4 amps like I do with my iCharger.  There are a number of quality high performance chargers available today that will let us charge multiple packs at once.  I now charge 4 packs at a time. So in less than 2 hrs I have all six of my packs ready to go.  And before I charge them again I can discharge them all to 3.7 volts per cell and then start the charging process with the packs all very close to the same voltage.  It only takes 10 minutes to discharge all six of my packs to the same voltage  for parallel charging.  This is a much better way for me, instead of taking 6 hrs. to charge my packs.  Just my 2 cents.   

Don't batteries have a limit on how many times they can be charged and discharged?

Don't batteries have a limit on how many times they can be charged and discharged?

Doc

What really happens is the performance of the battery starts to degrade. On some batteries this may start to happen after 40 cycles. On other batteries it may not start to happen until 150 cycles. (Note: a cycle being one complete charge & discharge).  So if you buy premium batteries, they last longer. I get two full flying seasons from mine, which translates to approx. 50 cycles, which for me is about 150 flights per season.