katman74

My Feedback: (23)

I accidently left the switch on and drained a 5000 mah life battery. Is it ruined or will it recharge

BarracudaHockey

My Feedback: (11)

Most life batteries will tolerate that a time or two without damage. I'd keep an eye on it as far as use versus recharge but you should be doing that anyways.

LLRCFlyer

BarracudaHockey is correct. If it has not been drained completely flat, there is a decent chance it may recover from a single deep discharge event. I have two Admiral (Motion RC) LiFe 2200 mah 2S batteries that I used as receiver/servo batteries in a plane with a high dollar Spektrum receiver that uses dual batteries in a "batt safe" configuration. However, the system has a "soft" on/off switch which stills draws a slight load, even when turned off. The instructions state to unplug the batteries if the plane is not going to be used for more than a few days. I accidentally left the batteries connected for too long and subsequently drained the batteries down to about 3 volts total (instead of 6.6 volts) before I caught my error. The batteries were not puffed, but I thought they were ruined for sure. I tried to recharge them on my LiFe charger, but it kept giving me a connection/cell count error message due to the low voltage. Since the batteries were also equipped with JR/Futuba style connectors, I took the batteries outdoors to a safe place and hooked each one to a standard old style non-monitored NiCad charger and monitored the voltage of each cell via the balance port. After a couple of hours, the LiFe battery voltage had increased to the point that my LiFe balance charger would recognize it as a viable battery and it then balanced charged the batteries. I carefully observed the charging process, and to my surprise, both LiFe batteries charged back to their full nominal voltage. I let the batteries sit overnight and rechecked the voltage the next day. All looked good. Then I did a discharge test of both batteries to see if any cell had suffered a loss of capacity. I only partially discharged the pack down to 2.9 volts per cell and recorded the mah-hr capacity that had been discharged. Comparing the capacity discharged against a standard voltage vs capacity graph (see below) indicated the batteries were retaining their rated capacity. I ran each battery through a few more charge/discharge cycles and finally convinced myself they had not been significantly damaged (if at all). If the voltage of your 5000 mah pack cannot be boosted enough with a regular NiCad charger to allow it to charge on a regular LiFe charge, then yes your pack is history. If it does restore to normal voltage, then do several charge/discharge test cycles with your charger to determine if the capacity of each cell in your pack has been damaged or not. If it passes all these tests, then it should be good to go.

Good luck,
David

BarracudaHockey

My Feedback: (11)

Its not a Lipo battery