discharge using car bulb

[wiseman]

thinking of using a 12v car bulb to discharge my batteries when i cant use them once charged, the set up is very simple, wired bulp to connector / battery, with a low voltage alarm attached, just wondering how long it would take to discharge one 11.1v 3s battery, in a word is worth the effort

[dillwhacker]

Headlamp bulb is 55 watts = 4.6 Amps at 12 Volts.
Full to 50% (storage charge) on a 2200 mAH pack = 1100mAH.
Don't go to LV alarm, go to 50%, approx 3.85 V per cell.
So 1.100 / 4.6 = 0.24 Hours, or about 14.3 minutes.
Assuming a 2200 mAH pack.
I do it all the time.

[Grumpy]

I use a modified hairdryer as a resistive load on my iCharger 4010 Duo. This discharges at 1000W so will take a 6s 5000mAh down to storage in about 5 minutes

[dillwhacker]

I use a modified hairdryer as a resistive load on my iCharger 4010 Duo. This discharges at 1000W so will take a 6s 5000mAh down to storage in about 5 minutes

THAT, my old weasel's wedding gear, is a bloody good idea! Like that a lot.
I've been looking for a self-cooling one-ohm one-kilowatt resistor for a while, and that is a very cool solution !
Pardon the pun.....

[Grumpy]

I copied Coolice's hairdryer mod using a Revlon 2000W hairdryer: RC Groups - View Single Post - 1875W hairdryer converted to resistive discharge load

[dillwhacker]

I copied Coolice's hairdryer mod using a Revlon 2000W hairdryer: RC Groups - View Single Post - 1875W hairdryer converted to resistive discharge load

Cheers dude.
Oh bugger - I don't have much hair - I haven't had a hair-dryer for 15 years...
How does a bald bloke buy a hair dryer??

[choppaholic]

i use the standard 12V halogen bulb that are used in household spot lamps, these can taken 6s lipos with no issue and glow quite bright on 6s, i usually use these to kill Lipos which are at the end of their life, leave it in there for a couple of days after you watch it go dim of course and is pretty safe after that to chuck it away, if a lipo is completely discharged there is no risk of fire, you can then pierce it and bin it.

never actually discharged a lipo of them yet but sure will work too

[Leigh Beaumont]

thinking of using a 12v car bulb to discharge my batteries when i cant use them once charged, the set up is very simple, wired bulp to connector / battery, with a low voltage alarm attached, just wondering how long it would take to discharge one 11.1v 3s battery, in a word is worth the effort

i used a bulb to kill a few old packs before binning them it took hours to flatten them totally

[coolice]

Hey Guys.

As Grumpy has said the hair dryer load is a good option. With the iCharger DUO's we're spoiled as we can regenerative discharge from one channel to the other, LiPo one side, hair dryer the other and the charger controls how much and for how long the pack discharges.

If however you want a nice simple solution, many are raving about this:

1-6S Lipo Checker, Balancer & Discharger (Discharge 1~6S at 150W) | eBay

I have made something up myself which is fun for you DIY'ers, but at these prices it's a good option for a ready to go unit.

Attached is my home made discharger, works pretty much the same as the linked one, but is made from an online plan and a Cell Log 8M.
.

[st200ol]

I have one of those 150W dischargers, it works very well and takes all the hassle out of putting the packs I didn't get to fly back to storage voltage. Recommended.

Hey Guys.

As Grumpy has said the hair dryer load is a good option. With the iCharger DUO's we're spoiled as we can regenerative discharge from one channel to the other, LiPo one side, hair dryer the other and the charger controls how much and for how long the pack discharges.

If however you want a nice simple solution, many are raving about this:

1-6S Lipo Checker, Balancer & Discharger (Discharge 1~6S at 150W) | eBay

I have made something up myself which is fun for you DIY'ers, but at these prices it's a good option for a ready to go unit.

Attached is my home made discharger, works pretty much the same as the linked one, but is made from an online plan and a Cell Log 8M.
.

[cjcj1949]

We could design something very cheaply to switch off when the lipo gets down to storage volts, or even cheaper sound a buzzer. If anyone is interested send me a pm. I can produce a working circuit and the software if someone can do a pcb. An arduino with a prototype board and a buzzer would do the voltage check.

There is an easier way though and that's the low voltage alarm. Cheap and very loud.

1S-8S RC Lipo Battery Low Voltage Alarm Buzzer Indicator Meter Checker Tester UK | eBay