What Amp do I Discharge a Battery?

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parcou

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Newbie at this so trying something I have not done before...not 100% I am right in my process...

I have the Spektrum 3S 5000mah 11.1v Lipo batteries and I also use the Spektrum S2100 charger. I notice when charging this battery today one cell struggled to get to 4.2v but the other two cells did. It would get to 4.17-4.18 or so when the charger alerted done. When I hit done this cell would drop to about 3.8 or 3.7 which was strange to see while the other two held. When I began the charge again after being done this cell immediately jumped to 4.14 and begin to move up it was taking a long time so I stopped it at 4.17 before or "if" it would even get to 4.2

So after running the battery today, I thought I would just discharge all the cells to 3.4, and then storage charge it to 3.8 as normal. My hope when I charge NEXT I can get that cell to 4.2 if I can discharge all to the same number and then storage charge it afterward. I have never discharged. The S2100 charger was set to 3.2 discharge but I changed that to 3.4. The Amp rate is 0.2 but I can change that but this is what the charger had defaulted.

What is a good discharge "A" amp for this battery and charger?

BTW - The cells were at about 3.5ish one maybe have been at 3.6 when done running the BR.
 
Discharging like everything else is going to differ from pack to pack, but I generally do mine at 10A. It all depends on how accurate you need to be with your final voltage. I take mine down below 3.7v so I can put them on a storage charge and balance everything out.
 
^^^^^ thx for the reply

What is strange that when the discharge completed...all 3 cells said 3.41. When I hit done the cell in question then showed 2.89.

Try to storage charge it now.....weird...
 
Two possibilities:

1. You have one bad cell with internal damage. Internal resistance must be sky-high.
While connected to the charger it is being held high by the charger residual current. As soon as you turn it off it shows that it can't hold the charge and immediately drops.
Discharging, as you did, it crossed into the completely damaged region (below 3V), no idea why it showed the 3.4V, technically not possible tbh. Logically makes no sense either as you started out at 3.8V whiole the other cells were at 4.2V from above discussion.

2. The balance connector/contact or wire itself is damaged/corroded. It will give weird readings.

What is the total voltage? If it adds up to the individual voltages you do not have a balance wire issue but a bad cell.
 
Two possibilities:

1. You have one bad cell with internal damage. Internal resistance must be sky-high.
While connected to the charger it is being held high by the charger residual current. As soon as you turn it off it shows that it can't hold the charge and immediately drops.
Discharging, as you did, it crossed into the completely damaged region (below 3V), no idea why it showed the 3.4V, technically not possible tbh. Logically makes no sense either as you started out at 3.8V whiole the other cells were at 4.2V from above discussion.

2. The balance connector/contact or wire itself is damaged/corroded. It will give weird readings.

What is the total voltage? If it adds up to the individual voltages you do not have a balance wire issue but a bad cell.

Thank you....looks like #2 maybe it. I forgot I have a Spektrum XBC100 and I placed it on it....it read 3.80 for all cells and the correct total voltage. In the morning, I will dig in my box to see if I have another balance connector to replace it.

Thx
 
Just to make sure I got this right.

With your 3S you are getting 3x4.18V= 12.5V on the power leads but you get 4.18V, 3.8V and 4.18V on the cell values?
 
Just to make sure I got this right.

With your 3S you are getting 3x4.18V= 12.5V on the power leads but you get 4.18V, 3.8V and 4.18V on the cell values?

That is correct when I am using the charger. When I removed the battery and put it on XBC100 lipo checker they read correctly. I will check Saturday my cable I have the the balancer using another to see if I have the same issue
 
I have 2 dischargers. The ISDT FD200 and an ORI M42 a12. The Ori balance discharges up to 120 amps. It is auto regulating with amps. It decides. It will flash the cell # if you have a bad cell that cant keep up with the rest. It is the only balancing discharger that I know of. The ISDT has a much higher and user selectable amp discharge. But...it does not balance the cells. There is no Balance port.
The Ori was a demo for review. I was impressed with it. It will discharge a fully charged 6000mah 6S brick in 34 minutes. Balance was dead on correct and within .02v/cell as the specs stated. The ISDT works great also, it just doesn't balance the cells. So that leaves another balancing procedure for you to do at the end of the discharge cycle . Dischargers are not necessary if you have a decent Lipo charger that will balance well in Storage mode. It will just take longer. If yoru charger has a IR (internal resistance) check, this usually tells the story regarding what cells are failing or aging... and all packs have that one cell that drifts away from the others. IR's should be around 4-5 mili ohm's in a perfect f(new Lipo) scenario and close readings to each other. When IR's get as high as 15 you are pretty much done with that Lipo pack. The pack will cut out easily under load with a dumping cell(s). Just my observations.:cool:

EDIT: Correction...the ORI M42 discharges at 120 Watts, not Amps.



























































































































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I have 2 dischargers. The ISDT FD200 and an ORI M42 a12. The Ori balance discharges up to 120 amps.

Pretty sure you meant to say the ORI does 120 watts. 120amps would be pretty fantastic for $75! Would probably need a heat sink the size of a microwave!

Either way, I really like that... may add one to a Christmas list to take the load from my chargers on bad days when things break before I run out of charged packs...

Not as robust as the 35A discharge of the BD250:
https://www.amazon.com/SKYRC-BD250-Battery-Discharger-Analyzer/dp/B087NFJN67

But the balancing discharge is a nice feature, then you don't have to charge back up to storage.
 
Pretty sure you meant to say the ORI does 120 watts. 120amps would be pretty fantastic for $75! Would probably need a heat sink the size of a microwave!

Either way, I really like that... may add one to a Christmas list to take the load from my chargers on bad days when things break before I run out of charged packs...

Not as robust as the 35A discharge of the BD250:
https://www.amazon.com/SKYRC-BD250-Battery-Discharger-Analyzer/dp/B087NFJN67

But the balancing discharge is a nice feature, then you don't have to charge back up to storage.
Thanks for the correction.:) yes its 120 Watts. 120 AMPS could fry the lipo....:LOL: I hate giving incorrect info.. You know your stuff. Thank you again.(y)
That Sky RC discharger is real nice... specs and all. (y)
 
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Try this
https://www.smc-racing.com/oria12bb

Search by name shown on the picture ORI a12 and it brings you back into our galaxy :ROFLMAO:
"
The Ori a12 storage balance discharger allows you to discharge your packs to storage mode at 3.8v per cell. This unique discharger uses the balance port to properly set the cells at the proper voltage. It has 120W/8A of discharge power. You will be able to discharge 2S and 3S packs at 8 amps. 4S packs at 7 amps and 6S packs at 5 amps.
"
 
https://www.amazon.com/gp/product/B07ZD2D8YW/ref=ppx_yo_dt_b_asin_title_o04_s01?ie=UTF8&psc=1

Like I said earlier, I discharged a FULL 6000mah 6s brick in 34 min. Balanced and all. Impressive to me because it balanced well. It throttles the amps gradually. Fan is temp. controlled. It beeps to let you know its finished, shows the resulting volts, time to discharge and will flash the cell number(bad cell) that is out of sync, then shuts off in a minute if it is unattended.
The first one I received was DOA from AMZ prime. Packaged in an envelope. It was pretty beat up. I returned it. The seller reached out in response and sent me another direct from China Express shipping. FOC. I tested and reviewed it. It is not an RC specific item. It is used with Camera equipment also. Does not come with cables. SMC offers a cable setup included for RC specific use. It uses an XT60 port. :cool:
 
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A new question to my original.....Storage Charge

Had a fully charged 3S 5000mha battery and broke something on the RC. This left the battery above 4A the other day. I have the Spektrum S2100 charger so I placed it on the charger to do a storage charge from the 4.x to 3.8. It took a long time hours to get it down.

The storage AMP is 7.5 which is the same as the charge rate of 7.5. Now originally Spektrum battery out the box setting is at 12A charge but I slow it down to 1.5 charge rate.

Here is my question. I charge and storage charge at 7.5. Would it be bad when the battery is above 4.x and I want to get it down to a storage charge of 3.8 to change the AMP to 12A....to make it faster? So I am thinking that is not a good idea since it would be bad for the cells although in this case, I was not working with a depleted battery a full one? I'm not really sure....
 
That charger is only capable of discharging at 3A or less (usually limited by watts internally). So it doesn't matter what you set it to, it's going to take a while. The storage amps comes more in play when your below 3.85V, it will charge at that amp value you set, then drop off as it gets close to 3.85 to probably .5A or less.
 
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