I have the Phantom 1 with 5 dji 2200 stock batteries. The stock charger has 3 rates...1 amp...2 amp ...3 amp. What is the best rate to charge the batteries for the best life of the battery? I normally have mine charged fully but if it looks like I won't be flying soon I will discharge them and then do a storage charge with an after market charger TB6B by Tenergy.