How to drain a battery to 5%?

Tim Whittaker · Jun 8, 2015

Just wondering how everyone else are managing their batteries. The app keeps asking to cycle a full battery drain below 5%. How does one drain the battery safely? I tried hovering to get rid of the last of the power and @ 30% it shot off to climb out ready to perform a RTH misson which I promptly cancelled, I then held a hover until I got to 10% when it dropped/landed and powered down. With 5 batteries to power cycle periodically there must surely be an efficient way to perform this maintenance. Any help appreciate here
Thanks
Tim

The Editor · Jun 9, 2015

Tim Whittaker said:
Just wondering how everyone else are managing their batteries. The app keeps asking to cycle a full battery drain below 5%. How does one drain the battery safely? I tried hovering to get rid of the last of the power and @ 30% it shot off to climb out ready to perform a RTH misson which I promptly cancelled, I then held a hover until I got to 10% when it dropped/landed and powered down. With 5 batteries to power cycle periodically there must surely be an efficient way to perform this maintenance. Any help appreciate here
Thanks
Tim

A couple of ideas/method besides the one you mentioned:
1. Use the cable that came with the Inspire to charge the remote from another battery. Let it charge the remote until the batt turns off.
2. Some users have rigged up a 24v 35Watt halogen lamp and connected that via a battery terminal lead until the battery turns off.

robshaw · Jun 9, 2015

I've just done all my batteries by hovering. Like you say, cancel the the RTH at 30% and when it tries to land at 10% just keep the throttle up and it will stop it from landing. Maintain this until you get to 5%. Just be aware the percentage drops quite quick once it gets below about 10% so keep it really low, about 12" from the deck should be safe.

Kilrah · Jun 9, 2015

I've cut my charger's and the battery->remote cables and installed XT60 connectors inline, so I can connect the battery to my usual RC charger and do a discharge procedure there.

Shazbot4 · Jun 9, 2015

just wondering, how does dji say were suppose to do it? none of what i read sounds reasonable.

DCGOO · Jun 9, 2015

You can still fly the aircraft even after the battery drops to 10%. You simply have to hold extra up stick, when very close to the ground. I've been able to "fly" mine down to 1%.

If you are not comfortable doing that, you can fly until it lands, but then turn the aircraft back on, and let it sit until it dies. This may take an hour or more though, even after flying it down to 9%.

Mazz · Jun 9, 2015

Kilrah said:
I've cut my charger's and the battery->remote cables and installed XT60 connectors inline, so I can connect the battery to my usual RC charger and do a discharge procedure there.

This is an option?

LockMD · Jun 9, 2015

Shazbot4 said:
just wondering, how does dji say were suppose to do it? none of what i read sounds reasonable.

I like this one:

The Editor said:
1. Use the cable that came with the Inspire to charge the remote from another battery. Let it charge the remote until the batt turns off.

Sounds safer, haven't had to do it yet though so I don't know how long it would take.

Gary Bateman · Jun 10, 2015

Yes the best and safest way is to use the battery cable to RC to drain the bat. Had no probs at all. Just let the bat cool down before recharge.

Kilrah · Jun 10, 2015

Mazz said:
This is an option?

Is that a question?

Yep it works fine, I do a 6s discharge to 3.1V/cell, at 3A. The charger thus slows down discharge when it reaches 18.6V, and the discharge continues slowly until the battery's circuitry cuts off. Perfect

KnightOwl · Jun 10, 2015

Kilrah said:
Is that a question?

Yep it works fine, I do a 6s discharge to 3.1V/cell, at 3A. The charger thus slows down discharge when it reaches 18.6V, and the discharge continues slowly until the battery's circuitry cuts off. Perfect

Kilrah...if you don't mind I'd like to know a little more about your discharge method? WIthout a balance lead how do you know the individual cell voltages? Also I've tried researching using my Lipo charger on the I1 batteries and read that I should choose / select the Pb (Lead Acid) type because the TB47/48 doesn't have a balance lead, is that the selection you use?

Yt2 · Jun 10, 2015

The Editor said:
1. Use the cable that came with the Inspire to charge the remote from another battery.

Is that the official reason for that supplied cable is is it for something else? I wondered what it was for...Don't want to get in trouble for going off topic, but I need to know...

The Editor · Jun 10, 2015

Yt2 said:
Is that the official reason for that supplied cable is is it for something else? I wondered what it was for...Don't want to get in trouble for going off topic, but I need to know...

The official reason for supplying the cable is to utilize a battery to charge the remote whilst in the field.
All you would be doing is charging the remote until your battery turned off. (Obviously your remote battery needs to low enough to require a charge!).

Kilrah · Jun 10, 2015

KnightOwl said:
WIthout a balance lead how do you know the individual cell voltages?

I don't, no use. The battery's circuitry takes care of monitoring those anyway.

I don't charge with the RC charger, I found no good solution for that and the stock charger does its job good enough.

kenny kustom · Jun 10, 2015

My inspire has been gone for 15 days. All three batteries are still full. Have not discharged by themselves.
Anything i can do ? I have no rc or ac.

skylabimaging · Jun 10, 2015

I simply fly down to 10%...when I get home I just turn the inspire on untill it shuts off or you can check to see if it's below 5%

Kilrah · Jun 11, 2015

kenny kustom said:
My inspire has been gone for 15 days. All three batteries are still full. Have not discharged by themselves.
Anything i can do ?

Stop checking them. Everytime you check the level it resets the autodischarge timer. If they're set to discharge after 10 days and you check the level after 9 because you think more than 10 days have passed you'll have reset them and have to wait 10 days again.

Henrik M · Dec 4, 2015

if you have a charger that is pretty new the discharge with lipo program wont work, it requiers a balance cable to even start, im at this very moment trying the "PB" alternative.. I'll get back to ya

Henrik M · Dec 4, 2015

Ok, test done. My battery went all the way down until it shut off, tried to start it and it blinked for like 2 sek and then shut down. I use a Team Orion Touch Duo and it will not start on any other program than PB so I set the PB discharge to 10 cells (20V) , 5700mah, discharge 2A. It discharged in 0,6A all the time, but it took like 3h, on the other hand the battery was at 46%

AndyW · Jan 2, 2016

Kilrah said:
I've cut my charger's and the battery->remote cables and installed XT60 connectors inline, so I can connect the battery to my usual RC charger and do a discharge procedure there.

Can you post a photo of what the connector looks like. I want to make the same set up because i have 8 batteries to discharge to 5 percent.