iCharger 4010 Duo - What am I doing wrong?

[-Richard-]

I am trying to discharge 6 x 6s 5000 packs, I am doing the regenerative discharge to 20 x 12v 50w light bulbs, I have the iCharger maxed out at 40amps but the packs are only discharging at 5.5amps, what am I doing wrong? it shows 40 amps going to the bulbs and its getting pretty hot but I have seen vids of the guys discharging at 40amps from the batteries.

[fjoe]

Why are you only getting 3v on the load side?

6, 6s 5000mah discharging at 130w/h is going to take 5.5hours!

[fjoe]

What does the info say on the battery side? I see the voltage limit on your load side is 12v.

You will not get 40a on the battery side, it will be 20a max since the load is 12v and your 6s batteries are 24v.

[-Richard-]

Thanks fjoe,

I have no idea why I am only getting 3v on the load, this is a new charger for me and I have never done regenerative charging, do you think its just a setting thing that I need to change?
I didn't think to look at the info and now the batteries are at storage, I will charge a pack up tonight and start the discharge again and take a pic of the info screen.

Cheers

Richard

[-Richard-]

Ok, just started another discharge and same thing but I have captured the info page, I have no idea how to get the load voltage up.

[fjoe]

How did you wire up the lights up?

http://www.tjinguytech.com/charging-...ight-bulb-load

[fjoe]

Ok I think I got it!

Assumeing you have paralleled 20 50W bulbs (~3ohms) the equivalent resistance is 3/20 or 0.15ohms!

V=IR, or I=V/R so @12v the load will want to draw ~80A! and burn 960W. But since you are limiting it to 40A the voltage will never get there.

The charger limit is 40A, so I would re-arrange your load to be 24v (2 series bulbs in a parallel of 10) or only use 10 bulbs.

@12v the max power is 480watts
@24v the max power is 960watts

[Kiba]

Originally Posted by fjoe

Ok I think I got it!

Assumeing you have paralleled 20 50W bulbs (~3ohms) the equivalent resistance is 3/20 or 0.15ohms!

V=IR, or I=V/R so @12v the load will want to draw ~80A! and burn 960W. But since you are limiting it to 40A the voltage will never get there.

The charger limit is 40A, so I would re-arrange your load to be 24v (2 series bulbs in a parallel of 10) or only use 10 bulbs.

@12v the max power is 480watts
@24v the max power is 960watts

You are on the right track. The 4010 has a 40A current limit per port and at his current external load resistance the charger is hitting that 40A limit on the external load port at a rather low discharge amperage from the 6S packs.

To reduce the current you need to increase the resistance of the external load. To discharge a 6S pack (~22.2V) at the maximum 40A port current limit of the 4010 is about 900W that will need to be dissipated in the external load. Keep in mind the port the external load is connected to also has a 40A maximum current limit. A 1 ohm external load is about ideal for the 4010 (40V / 40A max per port, R = V/I.) That 900W into a 1 ohm external load would mean about 22.2A of current flowing through the external load which is well under the 40A current limit of the port connected to the external load.

You can use lightbulbs or a bank of high wattage resistors in series or parallel to achieve the ideal 1 ohm resistance (resistors are preferred and cheap enough off of ebay.) Another inexpensive but effective method is to take apart a hair dryer and attach one wire at the appropriate point on the nichrome heating element wire to "adjust" the resistance of the heating element to be suitable for the iCharger.

[-Richard-]

fjoe, Thank you so much for your help, I have taken out half the bulbs (so now using 10) and it works great

Cheers

Richard

Thanks Kiba, as you said with the 20 bulbs there wasn't enough resistance, 10 bulbs is working pretty good so will stick with that for a while, the sun is back today so i'm going flying revisit this when the rains are back.

[Kiba]

Originally Posted by -Richard-

fjoe, Thank you so much for your help, I have taken out half the bulbs (so now using 10) and it works great

Cheers

Richard

Thanks Kiba, as you said with the 20 bulbs there wasn't enough resistance, 10 bulbs is working pretty good so will stick with that for a while, the sun is back today so i'm going flying revisit this when the rains are back.

Glad to hear it's working better.

FYI, you may find this post (and attached spreadsheet) useful in the future when it comes to figuring out your external discharge load...

http://www.rcgroups.com/forums/showp...postcount=2294

With that spreadsheet you can easily see discharge wattage and amperage from the pack as well as the voltage and amperage the discharge load will experience depending on the resistance of your external load. Again, about 1 ohm is ideal for the 4010 to stay within the 40V/40A port limits. Also verify your external load is capable of dissipating the amount of wattage you'll be sending to it!

[-Richard-]

Awesome, thanks Kiba