CJKling

My Feedback: (1)

Hello All,

Recently purchased a Triton Jr. charger/discharger, Equinox lipo balancer, and a 3 cell, 11.1V, 640 mAh lipo for a foamy I built a while back.

I'm looking to store the battery until warmer weather (3 months or so), and would like to get it to about 40-50% of capacity for storage. I want to discharge the battery fully, then recharge to 50%. My question: What is a safe discharge rate? 0.5 Amps? My charger automatically takes a cutoff voltage of 9.0V (3 V per cell). I've read that over-discharging lipos can kill them and I would like to avoid this.

Thanks

Sadri

If you discharge LiPo below 3 Volt per cell , your lipo die!!!! you have to storage your batteries with storage mode of your charger.

redfisher1974

3.8v per cell is what you want for storage.

CJKling

My Feedback: (1)

So in short to answer my question: would I be okay to discharge at 0.5 A to 3.0V per cell, then recharge halfway?

bgosselin

Yeah, that would work. Lipos have a limited number of cycles to begin with, so I'd run it in your plane instead of wasting a cycle discharging.

CJKling

My Feedback: (1)

Okay, I may just store as is then (received from Towerhobbies) until its time to fly. Thanks for the help.

AltaTed

I found it suggested that Lipo batteries do not need discharging should not be, and if stored even a year they will still keep 95% of the power you had them charged to. They do not form as other batteries do so they should not be discharged like other batteries or you will kill them. They should never ever be completely discharged.

I too would like to know more on these as I have completely converted over to lipo's.

AltaTed

bgosselin

It has been found that corrosion happens inside the cell when stored for long periods at full charge, hence the "storage mode" on many chargers. Typically, 3.7-3.8v is used as a guide to know how much to charge/discharge. Otherwise, you'd have to start with a fully charged or fully depleted lipo and charge/discharge to half the capacity to achieve the "half charge" mark. Easier to use voltage as an estimate.

AltaTed

Thanks for corrosion advice. Question is how to bring a fully charged battery back down to good storage voltage indoors ?  We have had constant weather preventing outside activites for months so my batteries sit charged waiting for good weather.

Good old rainy Pacific Nort West.  (also snow we have had on ground over a week now, but it finally started raining again today).

AltaTed

bgosselin

Just put the battery on the discharger and manually stop the discharge when the voltage gets to ~3.8v per cell.  I don't know what C rating on that 3s 640mAh pack is, but I'm sure you could discharge as high as 5A without any issue (providing the charger allows it) and it won't take too long...

redfisher1974

Thats what I use my discharger for, when I charge up a pack and cant use it for a few weeks. I made one from 12v lightbulbs

AltaTed

One more kudo for the data.     I just got my new charger in the mail today, opened it up and as you said, it has a discharge cycle for battery storage.  The charger that came with my trainer plane said nothing but the storage info for a year and how to charge..
Thats what I used to charge the first lipo.

I'm just learning about lipos and all this good info should save me bucks in the long run.  I'll do a discharge on the only lipo battery I charged this afternoon.

AltaTed

CJKling

My Feedback: (1)

Thanks for the help all.

Does anyone know what the display readouts on the Triton Jr are during discharge, particularly the voltage? I'm assuming this is the battery voltage and this is what I used to know when to stop discharging...

bgosselin

For all the chargers I've used, the voltage display shows the current battery voltage whether it is charging, discharging, or just sitting there.

guver

My Feedback: (325)

Try discharging at max current on the Triton JR down to 3.5 per cell. The voltage may spring right back up to the storage voltage you desire, adjust up or down as required. The resting voltage should really never be lower than 3.5 per cell.

AltaTed

I tried doing a storage discharge using my new Titan B6 for the first time and with 3 batteries I got signal Connection Break. reading with all three of them.    I checked and all the batteries were up in the 12V range.  This is a new charger and it's first use.  I suspect it's defective. Has anyone ever seen this situation?

AltaTed

Sadri

do you use balance conector of your batteris connected to charger?

AltaTed

Here lies my problems. I don't yet have enough knowledge to understand the needs of lipos. 

I connected directly into the charger port matching my batteries. Four pin connection for 1800 mAh  11.1 V batteries

The charger automatically set up to 1Amp discharge  down to 3V

From here I am lost.

AltaTed

guver

My Feedback: (325)

You do need also to use the main leads, may that is trouble?

AltaTed

OK, My main leads have a connector that has asmall  bar sideways on red and a small bar lengthwise on black lead.  I don't have jumper adapter to the banana  female plugs into the charger.  Is this what is done ?  Should I set one of these up ?

AltaTed

guver

My Feedback: (325)

Yes, the main lead needs to be hooked up to do any charging.

AltaTed

Good, I made a jumper to connect the leads to the charger.  All seems to work fine now. 

When on it's storage cycle and set at 1 amp do I need safety shielding like used when charging ?   

 Sooner or later I'll have enough knowledge to be dangerous.

AltaTed