I know, best answer is go fly...

OK, you flew, you crashed on your first battery, and you have 5 more fully charged lipos that you need to reduce to storage charge.  Any tips, tricks, or contraptions (or recommended links to such)?  I've got a SC-608 charger and its maximum discharge rate is 5W.  On a fully charged 4S battery that gives me a discharge current of 0.3A.  It is very slow...

It would be nice if I could monitor the voltage while I'm at it - it would be even better if I could wire something in with my charger to cut off the discharge when it reaches storage voltage. I'd be happy discharging at 1 or 2C.

Anyway, just thought I'd ask to see how others are doing this.

Thanks.

I'm lazy. I don't.

Summer is hot though, thinking about setting PIDs to zero and using my quad as a fan lol

(03-Jun-2017, 02:22 AM)fftunes Wrote: I'm lazy. I don't.

Same here for years - however, I'm trying to turn over a new leaf   
(Plus I'm beginning to buy more expensive batteries - and since I'm recently retired, I've got to "s-t-r-e-t-c-h" my resources...)

My charger will discharge at up to 20W. It's still not much, but when I come back from the field, if I have any batteries that are still charged, I just plug them in to my paraboard and discharge them to storage voltage.

Sure, it might take a few hours but I don't view that as an issue. The only time I'm impatient with my charger is when I'm waiting for batteries to charge so that I can get on my way.

I use this
https://www.banggood.com/AOK-3-in-1-150W...01201408U4 (affiliated)

It comes with light bulbs as well so you don't need to buy/build your own...
It can discharge and stop at whatever voltage you set...

What unseen said........

(03-Jun-2017, 10:57 AM)Oscar Wrote: I use this
https://www.banggood.com/AOK-3-in-1-150W...01201408U4 (affiliated)

It comes with light bulbs as well so you don't need to buy/build your own...
It can discharge and stop at whatever voltage you set...

That's a great idea if you have a lot of batteries, or some very large ones to return to storage charge. Super cheap as well!

What do you do with the light bulbs though? I guess they get far too hot to cover them with anything.

(03-Jun-2017, 09:20 PM)unseen Wrote: That's a great idea if you have a lot of batteries, or some very large ones to return to storage charge. Super cheap as well!

What do you do with the light bulbs though? I guess they get far too hot to cover them with anything.

Yea bulbs get very hot.. some people would build a station to sit them on, like a wood block or something...
I simply put them in a metal can or a bowl while using it... 
it's basically using the same principle as my DIY bulb discharger, but this one has voltage control

I am in a similar camp with unseen and sirdude. When the charger tells me it ran past the maximum time... I reset it and let it keep discharging.

I usually go for about 3 batteries at a time to reduce the number of resets...

In general I keep the charger right by me while I zombie out to some TV or catch up on intoFPV

I use the same as Oscar mentioned and it works perfectly. I connect a balance board to it and discharge 6 packs at a time

if only I could get my hands on one of those dischargers I'd be joining you folks in the club of blue...

it's on my wishlist for now.

As mentioned above, I've got the iSDT SC-608 charger, but it has a maximum discharge power rating of 5W which is very slow.  (I had been using a older FMA charger for all my charging, but it wouldn't charge LiHV and it had no discharge cycle - two reasons I bought the iSDT.)

I appreciate all of the suggestions here.  I actually have a halogen light set-up that I had used in the past for discharging my A123 packs and I was going to use that, but I really wanted it to be more automatic and shut off when it reached storage charge.  I thought I might need to buy a more high powered discharger like those suggested (but I didn't want to spend any more money) - then I ran across this video:


I really liked the idea of using the excess charge of unused packs to charge or storage-charge packs that I needed, so I started going through my packs and almost all of them were already at storage charge or above.  Near the end of the video he mentioned in passing that "you could use a 12V car battery - they'll always take more mAh's"  (and he superimposed the Pb charger settings needed for the SC-608).

I recalled I had an unused motorcycle gel-cell battery, so I dug it out and what follows is how I am discharging (for now anyway).  It works great!

Here's what the set-up looks like.  On the SC-608, the power supply plugs in the top, and the battery being charged plugs in the side.  (I have a parallel charging board on the way so I can charge/discharge multiple batteries like he does in the video.) In the photo below, the Revolectrix LiHV is being "discharged" to charge the Pb battery.


The trick to making it stop discharging is to reset the "Min Input Voltage" in the system settings.  Below are the screens for setting up the SC-608 to do this.  Since the recommended storage voltage for the Revolectrix is 3.85V per cell (15.4V), I set the Minimum Voltage to 15V thinking I would need to balance charge the cells to 3.85 after discharging.  (The charge setting for Pb batteries is 2.0V and 6s.)


Clicking "Start" will start the charge/discharge cycle.  The Revolectrix discharged at 36W and took less than 20 minutes to finish!  What an improvement!  The photos below show the cycle near its end.  When the voltage of the Revolectrix dipped below 15V, the "charge" stopped and the charger made an annoying sound that I can hear throughout my house - perfect!


So next, I set up to balance charge the Revolectrix back up to 3.85 per cell, but when I put it on the charger,  the cells were already at 3.83V and I decided "close enough".  Makes sense that the voltage would bounce back a bit from the 15V (3.75 per cell) under load.


The recommended storage voltage for regular lipos is 3.8V per cell, so if those also bounced back to 3.83, I'd also say "close enough".  I also discharged a couple of 3S regular lipos.  I set Min Input Volts to 11.0, and the cells were at 3.77V when done.  I am very happy with this method of discharging!

That's a great bit of lateral thinking there, using the batteries you want to discharge as the power source for the charger!

Very cool solution!

One thing that I've taken to doing with my batteries to fine tune where they are in relationship to storage charge is I line them all up by Voltage. Lowest voltage on the left, highest voltage on the right (usually I'll have a battery or two at 14.8, several between 15-15.3, and then a couple at high 15s)... Then I start to hook them up to the parallel board in sets. So for example if I have the following : 14.9,15.1,15.1,15.5 then I start by hooking up the 15.5 and one or two of the 15.1s... I let it sit for a few minutes and then pull a couple of the batteries off to see if they match voltage. if they do then I hook them back up and add the 3rd 15.1 (and 2nd if I hadn't already). Then I check voltage again a couple of minutes later. If they're all aligned then I hook all 5 up and let it set for a few more minutes, verify again, and then if everything is lined up I hook up the balance leads and let them even out as well. At the end of this exercise they're likely to be at about 15.1-15.2 or so. If not then I'll put them on the charger to make up the difference.


(Disclaimer/Note to readers: don't do what I do on batteries unless someone tells me it's a good idea below. I am currently in process of troubleshooting battery issues and so just about anything battery related that I am doing is currently suspect)

BTW the charsoon charger from banggood (and probably any other original or clone chargers of this type) is able to discharge using a resistive load like a light bulb or do regenerative discharging back to a supply battery. I did a review for Oscar's blog where I tried both features and it worked well:

https://oscarliang.com/charsoon-antimatt...o-charger/