dgerhard

My Feedback: (10)

I have a strange issue with 2 hobbico life batteries. I had them in my plane 2 days ago, charged them up and all was good. Tonight I was going to put them in storage mode, one took 17mah the other 47mah. Long story short I was going to charge them back up, one took 87mah the other 52mah. Charger said both batteries were done. Both packs read 7.20. That got me thinking, so I put them back in storage mode again, same thing 5 min later said they were both 6.6 with less then 50mah removed. So I repeated the process again, same result. Tried a different charger, same thing. What are the odds that both packs went bad at the same time. I looked at the settings on the charger just to verify and everything is correct.

thepamster

Discharge your Lifes down to 2.5v per cell and see how much capacity is there and if it matches roughly the amp rating of your pack.
Try a storage charge from the point of your discharged battery and see what happens. I think it should only put back in 50% or so of your total capacity, for storage.
My charger manual doesn't explain much about storage charge but I would think it should discharge at first before it starts to charge.
I am sure others will chime in and correct me if I am wrong.

aghost

My Feedback: (13)

I doubt your packs are bad. I have four button type chargers. The results of their storage mode operation is similar to what you are seeing. They just pull out a few mahs and call it good. I do the storage mode as a manual operation. Watch the discharger (or charge) until the pack has 40% - 60% charge.

Brian

dgerhard

My Feedback: (10)

I'll give the discharge a shot when I get home. Had the packs for almost a year and this is the first time I have run into this

Truckracer

My Feedback: (19)

When using the 4 button chargers, I usually discharge Lixx batteries in Nixx mode as that way I can set the cutoff point within .1 volt. I have no idea where they cut off in Lixx mode. Just be sure to switch back to Lixx mode when charging!

Another possible issue ..... are you charging / discharging through the standard JR connector or the Deans plug? Voltage drops through the JR plug and associated small gauge cables can give false readings / charge and discharge rates. The higher capacity Deans connector will give much more reliable results.

thepamster

I have two four button chargers of different brands but essentially the same and they discharge Life batteries down to 2v per cell before cutting off. According to my battery manufacturer it should not be dischharged below 2.5v per cell. So I manually stop my discharge at 2.5v per cell.
I have gotten a low cell warning by using the 2v per cell discharge cutoff so I go by what the manufacture says.

dgerhard

My Feedback: (10)

Batt 1 is not going to be in service. Full balance charge according to charger then a discharge @0.4 brought one cell down to 2.43 in 17 minutes.
Batt 2 took a few hours to discharge, balance charge 3.6 cell 1 & 2 took a little over an hour and a half.

I did try batt 1 on two different chargers hitec 4 port charger and a venom pro charger both gave almost same output.


@ truckracer, no I don't use the universal plugs to charge/discharge. I always use tad deans
@ thepamster, I went from storage to full and took a little over 9 minutes on batt 1.

thanks for the input guys.

tacx

My Feedback: (1)

Why are you discharging life packs? You don't need to.

rexbirk

If you are going to discharge them use the nimh setting and set the cutoff voltage no lower than 2.5. All my 4 button Accucell Chargers will give errors if you use the life setting. It tries to discharge to 2 volts and errors when one cell drops too soon.

tacx

My Feedback: (1)

Again, why are you discharging life packs?

thepamster

Tacx, you might be under the assumption that when you put 200ma back into your Life 2100ma battery pack then you must have had 1900ma capacity remaining. Well, I am not going to go by your assumption and I will discharge my fully charged Life packs down to a predetermined level to determine the battery's actual capacity.
What do you do? Read the label? Lol.

tacx

My Feedback: (1)

Yikes!! It was a simple question that only needed a simple answer. Like "just checking capacity".
Sorry it got your panties in a wad.

thepamster

What, my answer wasn't simple? Ok perhaps a little snotty. I apologize. No wadded panties here.

Truckracer

My Feedback: (19)

Regardless of chemistry, in my shop any battery used as a flight pack gets a capacity check at least once a year. As Pamster said, there is really no other way to check the true capacity of a battery. Discharging LiFe batteries to a safe level at a low "C" rate does them no harm.

rexbirk

+1 on that. I would not want to find out the pack is going south while flying. I would much rather find out on the bench!