Discharge batteries to storage condition

[raylo32]

Just curious about how the DJI smart batteries BMS works and how best to place unflown batteries in storage. I know you can simply fly them down about half way but sometimes that just isn't possible. If you fully charge a battery and end up not flying it does the BMS automatically bring it to storage voltage over time (if so, how long?)? If the BMS doesn't do that it or if it maintains essentially full voltage for a long time I'd rather discharge it to storage, but how best to do that? Does anyone have a source for adapters that will connect the DJI batteries to a standard R/C charger that has the ability to discharge to storage condition? I have the chargers, just need an adapter or 2.

 

[Kilrah]

BMS brings it to storage after 10 days unused.

 

[zocalo]

IIRC, the BMS will automatically bring the battery down to storage charge after 10 days of sitting on the shelf.

If you have the Flymore kit and want do it manually (e.g. prior to airline travel, although this is not a requirement), then you'll have a little widget that you can plug into the battery that lets you use it as a USB powerbank. Connect that and use it to charge phones, tablets, or whatever until you get the level down.

 

[msinger]

If you fully charge a battery and end up not flying it does the BMS automatically bring it to storage voltage over time (if so, how long?)?

The batteries will start to auto discharge down to the storage level (around 60%) after 10 days of no use. It will take 1-3 days beyond that point for them to discharge down to that level.

Does anyone have a source for adapters that will connect the DJI batteries to a standard R/C charger that has the ability to discharge to storage condition?

Here are a few devices that can discharge Mavic 2 batteries down to the storage level:

IRCtek Battery Discharger




Mavic Angel Battery Discharger (see it in action here)





And, while not technically a battery discharger, you could use the DJI Battery Power Bank Adapter to drain the batteries by charging other electronic devices (like a phone or tablet). If you use this device, you'll have to monitor the battery charge level and disconnect the battery when it has been discharged to the desired charge level.

 

[raylo32]

I have been looking around and found this. Looks like it will work but All I really need is the cable since my R/C chargers have an auto program for discharging LiPos to storage.

Amazon.com: 1.5A Discharger for DJI Mavic 2 Pro/Mavic 2 Zoom Battery : Toys & Games

Buy 1.5A Discharger for DJI Mavic 2 Pro/Mavic 2 Zoom Battery: Battery Chargers - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

 

[Former Member]

I have been looking around and found this. Looks like it will work but All I really need is the cable since my R/C chargers have an auto program for discharging LiPos to storage.

Amazon.com: 1.5A Discharger for DJI Mavic 2 Pro/Mavic 2 Zoom Battery : Toys & Games

Buy 1.5A Discharger for DJI Mavic 2 Pro/Mavic 2 Zoom Battery: Battery Chargers - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

How many amps would you discharge it at with your RC discharger?

 

[raylo32]

I'd have to dig into the settings to see that. It has default profiles for chemistry (LiPo, li-ion, li-fe, pb, etc., nominal voltage (1S through 6S), and size in mAH that determine discharge rate and terminal voltage. These parameters can also be set manually.

How many amps would you discharge it at with your RC discharger?

 

[Former Member]

I'd have to dig into the settings to see that. It has default profiles for chemistry (LiPo, li-ion, li-fe, pb, etc., nominal voltage (1S through 6S), and size in mAH that determine discharge rate and terminal voltage. These parameters can also be set manually.

What kind of charger do you have? I have a charger that discharges at 5a. Makes short work of LIpos.

 

[raylo32]

It's a ProTek Prodigy 4 channel. Will easily do 5 amps. I think it goes even higher. I wish Mavic 2 charge adapter cables were readily available so I could use this instead of the Mavic 2 specific chargers.

What kind of charger do you have? I have a charger that discharges at 5a. Makes short work of LIpos.

 

[Former Member]

It's a ProTek Prodigy 4 channel. Will easily do 5 amps. I think it goes even higher. I wish Mavic 2 charge adapter cables were readily available so I could use this instead of the Mavic 2 specific chargers.

I saw some somewhere on the forum. The fellow that was making them used a simple cigarette lighter adapter, and cut the end off an M2 power supply. Cheap and easy if you dont mind soldering.

 

[raylo32]

I love soldering, but I hate to buy and trash a power supply just for the cable. I ordered that cheap discharger from Amazon, but even that is too much to spend just to get the cable. I am surprised vendors don't offer the cables since many of us come from the RC world... even previous drones like Iris+ used standard LiPos with XT-60 connectors that you charge on standard balance chargers.

I saw some somewhere on the forum. The fellow that was making them used a simple cigarette lighter adapter, and cut the end off an M2 power supply. Cheap and easy if you dont mind soldering.

 

[Former Member]

I love soldering, but I hate to buy and trash a power supply just for the cable. I ordered that cheap discharger from Amazon, but even that is too much to spend just to get the cable. I am surprised vendors don't offer the cables since many of us come from the RC world... even previous drones like Iris+ used standard LiPos with XT-60 connectors that you charge on standard balance chargers.

Yep. You can get an OEM DJI charger used for less than $20. just snip off the end, and youre good to go.

Alot of the drone modders, including me, use XT60's to connect external saddle packs. I personally prefer to sue Deans connectors, but XT60 are ok too.

 

[raylo32]

This is the charger I have.. or probably the previous generation of it. Says max discharge is 2A. Not sure if mine is the same, but it gets the discharge job done pretty quickly on my Iris+ 5100 mAh batteries.

edit: no, this is the one I have, it does discharge at up to 5A.

ProTek RC "Prodigy 610 QUAD AC" LiHV/LiPo AC/DC Battery Charger [PTK-8517]

This is the ProTek R/C "Prodigy 610 QUAD AC" LiHV/LiPo/LiFe/NiMH AC/DC Battery Charger. A quad port AC/DC charger that can handle 6S packs, is capable... PTK-8517

www.amainhobbies.com

 

[raylo32]

And here is an even cheaper way to get cables: Amazon.com: Battery Charger for DJI Mavic 2 Pro/Zoom, Elevin(TM) 2 in1 USB Car Charger Remote Control Battery Charger for DJI Mavic 2 Pro/Zoom: 29: Cell Phones & Accessories

Or this: Amazon.com: Sunnylife for DJI Mavic 2 Drone Battery Car Charger Remote Controller USB Charger 3 in 1 Car Charger Adapter for DJI Mavic 2 Pro & Zoom Battery & Controller: Toys & Games

Cheaper still: Amazon.com: Car Charger for DJI Mavic 2 Pro/Zoom Intelligent Multi Dual Charger Fast Charge 2 Battery & 1 Transmitter Dual Battery Parallel Charger: Electronics

 

[FormerMember07122019_2]

If you press the button on the battery to check to see how much charge is present it seems to reset the 10 day timer. Has anyone else noticed this? I can’t find anything in the manual to confirm this behavior.

 

[Dhudspith]

It's a ProTek Prodigy 4 channel. Will easily do 5 amps. I think it goes even higher. I wish Mavic 2 charge adapter cables were readily available so I could use this instead of the Mavic 2 specific chargers.

I found them on eBay and Amazon. Just search for Mavic 2 Charge cable.

 

[raylo32]

I did look on Amazon. Didn't find? I'll have a look at FleaBay.

I found them on eBay and Amazon. Just search for Mavic 2 Charge cable.

 

[raylo32]

Found 'em on eBay for $14.99. I'll just get the cheap Amazon $12.99 car charger that has 2 and cut 'em off.

Edit: also found a listing for $8:00 on eBay...: New Charger Charging Cable Adapter For DJI MAVIC 2 Battery to B6 B6AC Balance | eBay

I did look on Amazon. Didn't find? I'll have a look at FleaBay.

 

[kilomikebravo]

Mike S: Here's another one to add to your list:

RCGeeks Charger

I picked one up and charge to storage level works as advertised. A much better solution than watching each battery charge and stopping at "around" 65 percent.

 

[Dhudspith]

Found 'em on eBay for $14.99. I'll just get the cheap Amazon $12.99 car charger that has 2 and cut 'em off.

Edit: also found a listing for $8:00 on eBay...: New Charger Charging Cable Adapter For DJI MAVIC 2 Battery to B6 B6AC Balance | eBay

I bought 4 of them for just over $15 on ebay ( Fast Charger Charging Cable Adapter For DJI Mavic 2 Battery To B6 B6AC Balance 809620099315 | eBay )

I haven't used them for discharging, but have parallel charged 3 batteries at once with 12 Amps from my hobby charger. Works like a charm and much faster then the DJI charger.