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Old Nov 03, 2013, 07:23 PM
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LIPO discharger needed

I am of need of a lipoly discharger with auto cut-off at 3.8v per cell--'commercially' available

For 6S LIPO 5300mah
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Old Nov 03, 2013, 07:36 PM
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Imax B6 - the discharge current 0.5A.
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Old Nov 03, 2013, 10:36 PM
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Most smart chargers have a storage function. Consult the manual.

mw
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Old Nov 04, 2013, 05:30 AM
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Commercially ? Not many and likely not budget priced !

Search forums like this and Wattflyer and you find threads of constructing dischargers like my Light-Bulb version.

To create an auto-cut-off DIY discharger is not impossible and odd threads have done them ... but in the end KISS rules and a simple stopwatch .. or even clockwork timer is useful !

I have looked at using the clockwork relay that is in my old NiCD car chargers ... it connects system and then cuts when it hits zero. The spring winds up for a max duration of 30mins.

Nigel
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Old Nov 04, 2013, 06:09 AM
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A Cellpro Powerlab charger or WMR CBA would be your best options. You didn't specify how much discharge power you need.

http://fmadirect.com/

http://www.westmountainradio.com/cba.php
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Old Nov 04, 2013, 08:14 AM
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Quote:
Originally Posted by crashdaily View Post
Imax B6 - the discharge current 0.5A.
Thanks'
But, I need something in the range of 10 to 30 amps range for discharge so it would not take all day.
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Old Nov 04, 2013, 08:50 AM
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Really your only option then is a West Mountain Radio CBA. Hopefully you have a fat wallet.

While a PowerLab 6 or 8 can do a 30 amp discharge it will be regenerative so you will have to put all that energy back into a very large deep cycle battery. I'm guessing that won't fit your needs.
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Old Nov 04, 2013, 09:17 AM
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Originally Posted by Go4it View Post
Thanks'
But, I need something in the range of 10 to 30 amps range for discharge so it would not take all day.
What's your budget?
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Old Nov 04, 2013, 10:18 AM
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Quote:
Originally Posted by Go4it View Post
I am of need of a lipoly discharger with auto cut-off at 3.8v per cell--'commercially' available

For 6S LIPO 5300mah
Do you usually end up with discharged packs and some fully charged packs? If so, a simple parallel connector and resistor between discharged and fully charged packs works nicely. Not commercial but very simple.
See this thread.
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Old Nov 04, 2013, 10:43 AM
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Or another simple (but semi commercial) method is to use 2, 100W 12V RV bulbs in series with a 15 min timer like this..

If my figures are correct that will discharge a 6S 6000mah pack in 18 min or one turn of the timer dial.

6000mah/2 = 3000mah to get rid of.
2, 120W bulbs in series at 24V = about a 10A draw.
3000mah/10000ma = 18 min.

So a 5300mah pack should be about 1 turn on the timer.

Somebody check those numbers...
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Old Nov 04, 2013, 10:46 AM
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Originally Posted by Ohmic View Post
A Cellpro Powerlab charger or WMR CBA would be your best options. You didn't specify how much discharge power you need.

http://fmadirect.com/

http://www.westmountainradio.com/cba.php


I have a CBA but it is made for smaller lipo's in fact if anyone wants it I'll list it for sale?
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Old Nov 04, 2013, 10:53 AM
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Quote:
Originally Posted by hoppy View Post
Or another simple (but semi commercial) method is to use 2, 100W 12V RV bulbs in series with a 15 min timer like this..

If my figures are correct that will discharge a 6S 6000mah pack in 18 min or one turn of the timer dial.

6000mah/2 = 3000mah to get rid of.
2, 120W bulbs in series at 24V = about a 10A draw.
3000mah/10000ma = 18 min.

So a 5300mah pack should be about 1 turn on the timer.

Somebody check those numbers...

Looks good
I have been using a EDF test stand and running the EDF for a few minutes with a cell logger attacked and then disconnect at 3.8 or 3.7v. The reason I ask I am getting tried of the noise of the fan. But it is fast at 85amps discharge . I don;t like lipo's to set at full charge for more then a few days.
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Old Nov 04, 2013, 10:59 AM
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Originally Posted by Go4it View Post
I have a CBA but it is made for smaller lipo's in fact if anyone wants it I'll list it for sale?
You much have some very large LiPos then if the 2,000W version is too small for you.

http://www.westmountainradio.com/pro...d=sys2000_watt
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Old Nov 04, 2013, 11:09 AM
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Quote:
Originally Posted by Go4it View Post
Looks good
I have been using a EDF test stand and running the EDF for a few minutes with a cell logger attacked and then disconnect at 3.8 or 3.7v. The reason I ask I am getting tried of the noise of the fan. But it is fast at 85amps discharge . I don;t like lipo's to set at full charge for more then a few days.
It is true that leaving LiPo standing at more than storage is bad for them ... but also repeated 85A discharges when not necessary are not so good either !!

Do you not consider it would be a nice holiday for your LiPo's to be discharged at a less stressful rate ?

The timer ... I never thought to use a Domestic Wall timer .... One like that fitted into my system would be excellent !! Thanks Hoppy

Ebay here I come .... !!

Nigel
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Old Nov 04, 2013, 01:09 PM
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Quote:
Originally Posted by hoppy View Post
Or another simple (but semi commercial) method is to use 2, 100W 12V RV bulbs in series with a 15 min timer like this..

If my figures are correct that will discharge a 6S 6000mah pack in 18 min or one turn of the timer dial.

6000mah/2 = 3000mah to get rid of.
2, 120W bulbs in series at 24V = about a 10A draw.
3000mah/10000ma = 18 min.

So a 5300mah pack should be about 1 turn on the timer.

Somebody check those numbers...
Those timers are designed to switch AC, not DC.
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