Discharging batteries

[Merlin]

I charged up my Typhoon H batteries ready for a morning of flying then I needed to cancel.

So, here I am with two fully charged batteries. I'm still waiting for my Typhoon battery connectors to arrive although I do have a "smart" charger with a discharge option.

Looking through the documentation it talks about connecting up using the balance board. I wondered if this is actually needed as looking inside the Typhoon itself I see there are only two pins that connect to the battery. So, during flight it simply uses the batteries main + and - terminals and no balancing takes place.

So my questions are:

1) Can I discharge just using the + and - without using a balance board and is it safe to do so?
2) I will discharge down to 3.7v but what discharge amperage should I set the charger to?

I'm using a Prophet Sport Quad 4 x 100 AC/DC charger.

 

[BobW55]

With out using a charger/discharger, either fly them down to near storage voltage, or get a 12 volt automotive light and hook it to the main +- of the battery and monitor the voltage.
My Hitec X2 takes forever to discharge the batteries, easier and faster to fly them down.

 

[PatR]

One could find an old pair of socks, fill them with sand, place them on the landing gear to hold the H on the ground, and run the motors until battery voltage falls to 15.3v or so.

That's how I test current loads for new DIY builds.


Sent from my iPhone using Tapatalk

 

[Brian Mackey]

With out using a charger/discharger, either fly them down to near storage voltage, or get a 12 volt automotive light and hook it to the main +- of the battery and monitor the voltage.
My Hitec X2 takes forever to discharge the batteries, easier and faster to fly them down.

Mine times out LOL after 3 hours but it get them close to storage

 

[Dragonflyerthom]

Personally I think that they should be flown down. Plus it's a lot more fun doing it this way and faster too.

 

[Snagglesworth]

i use 30w 12v halogen light bulb (GU16) and a lipo alarm. Set the voltage on the alarm and the connect bulb. Make sure the bulb has plenty of ventilation as it will get very hot.

 

[D See Ker]

for now I just leave the H with motors running and without props. goes to 15v in about 1 hour

 

[KEN TARDIO]

i use 30w 12v halogen light bulb (GU16) and a lipo alarm. Set the voltage on the alarm and the connect bulb. Make sure the bulb has plenty of ventilation as it will get very hot.

I like using this method better than my charger discharge option. Set the alarm for 3.8 volts and no one is going to forget about it when the smoke detector type alarm goes off. Usually scares the crap out of me when it does. The alarm is only about $4.00 or less online.

 

[David Armstrong]

for now I just leave the H with motors running and without props. goes to 15v in about 1 hour

The only downside to this is the wear and tear on the motors.

 

[BobW55]

I like using this method better than my charger discharge option. Set the alarm for 3.8 volts and no one is going to forget about it when the smoke detector type alarm goes off. Usually scares the crap out of me when it does. The alarm is only about $4.00 or less online.

Ken, have a link to your battery monitor?

 

[Snagglesworth]

Turnigy Lipo Battery Voltage Tester 2-8S and Low Voltage Buzzer Alarm

That's the one I use. It's loud enough to wake the dead!!

 

[Haydn]

Turnigy Lipo Battery Voltage Tester 2-8S and Low Voltage Buzzer Alarm

That's the one I use. It's loud enough to wake the dead!!

This is the one I used in my steady grip mod.
Agreed that it is good and loud, can set the alarm to different values depending on what you want.

 

[Scatcat]

I use 3 marine 12v, 50 watt bulbs = 36v @50 watts for my QR X350 premium (33v battery) and this discharges the batteries to 30.4v(3.80v per cell) softly in about 1/2 hour. I have a switch to switch to a single bulb to discharge my Q500 11.4v 3 cell batteries. This discharges them in about 25 min to 3.80v per cell. I monitor with a
Cell checker. I found I have to go below the actual 3.80v per cell
As they regain some charge when unloaded from the discharger.
Works fine for me and the bulbs don't get all that hot. I agree, my
SkyRC IMAX charger takes well over 11/2hours to discharge to
3.80v's......way to long.