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Ribcracker
09-28-2005, 12:32 AM
I just bought a brand new THP1320-3SPL dated 8/18/05. Besides the usual 16 ga wires (which I will solder Ultras to), it also has a small 4 wire lead with a strange black 4 hole plug. There is no mention of this lead in the literature (the usual yellow sheet) that came with the pack and I have no idea what it is for. None of my other TP packs have this lead. Anybody know what it is?

Doppelganger
09-28-2005, 12:35 AM
I believe thats for balancing the cells. I could be wrong. Someone else will chime in soon.

Steve

Red Scholefield
09-28-2005, 01:11 AM
That is the sole purpose of the extra wires and plug, to enable one to balance the cells in the pack. Thunder Power is marketing a charger that interfaces with this connector to balance cells in the pack.

FMA Direct offers such a system in their new SKYVOLT offering that I have tested. It automatically balances the cells in a pack. It probably is not compatible with the connector used by TP. How the TP device implements the balancing I cannot tell without having one to test.

Vamooska
09-28-2005, 01:57 AM
These are called "taps". They tap into each cell so that you can either check individual cell voltage, independently charge one cell, or balance the entire pack. The ultimate purpose for adding these is that by keeping the pack "in balance" you will lengthen the life and efficiency of the pack measureably. How does a pack become "unbalanced"? by simply using it over periods of time the cells discharge at minutely different rates. This over time allows for one or more of the cells to vary from the target charge per cell. Lets say when you bought the pack it chrges to 12.56V. That puts each cell of a three cell pack at 4.18 volts. After time the cells may begin to vary...say one is 4.02V, one is 3.95V and the last is 4.59V. The total voltage is the same...but now you are overcharging one and overdischarging another....not good. The longer this happens the worse it gets. Ver important to balance.
Peace
Vammy

Ribcracker
09-28-2005, 03:31 AM
Vammy,
Thanks for the treatise on balancing. I see from your signature that you are in the "balancing" business. What equipment would I need to avail myself of these taps. Does TP have proprietary control of this devise? Are there any other options?
Peace,
Bud

Vamooska
09-28-2005, 03:40 AM
Well...my packs are all equipped with taps...even the 620 2 cells. I am sure that the TP devices will balance too. I know that mine balance to a 25mv tolerance..thats it. It is also done by microprocessor and not solely by resistors. It also takes the high voltage and feeds the low ones instead of simply discharging the high ones.
Peace
Vammy

bsoder
09-28-2005, 03:58 PM
Thunder Power sells the TP-205 balancer right now for 2-5 cells. They have another balancer coming out "soon" - TP-210, I think that's for 2-10 cells.

Vamooska
09-28-2005, 11:15 PM
Yea....That will be for the super serious flyer!
Nice product.

Ribcracker
09-29-2005, 02:14 AM
Right you are. I checked out the TP website and the TP-205 sells for $60. I wonder if that's a worthwhile investment or is it just another gadget for the gear heads.
Iv'e been using lipos for 2 years now and those that I haven't ruined through carelessness and stupidity are still going strong without ever having been balanced.
Oh, and Vammy...I checked out your site and the Vampowers look like a great deal. Next time I need packs, I'll try them.
Do any of you "tech" types have a basement method for balancing your packs?

Matt Kirsch
09-29-2005, 02:09 PM
It's not magic or rocket science. Each of the lines running to the balancing connector is connected between two cells. By using the right combinations of two wires, you can test the voltage of each cell, and charge each cell individually.

This particular setup has a connector to interface with ThunderPower's charger, but that doesn't mean you can't use the "taps" in a more generic fashion.

There are two ways these "taps" could be wired. Sometimes all the cells can be charged through the taps, but sometimes the battery manufacturer utilizes the main power connection on the pack to access the first and last cells. Hopefully someone knows what philosophy ThunderPower is using with these packs.

Balancing (charging each cell individually) only needs to be done occasionally under normal circumstances, partially because it's a royal pain in the butt to do it "by hand," but mostly because the cells don't get out of balance all that quickly. These balancing chargers make it much simpler, so it can be done every time. The hope is that keeping cells in balance will further reduce the instances of LiPoly incedents (i.e. not just fires, but puffed or otherwise damaged cells), and further increase their lifespans. Only time will tell, as this technology is just out of the gate at this point.

bsoder
09-29-2005, 03:49 PM
I have a 205 balancer, and since all my packs are TPs with taps, I just plug the pack into the balancer and then the charger. pretty much a fire and forget thing. If for some reason one of the cells is going really high the balancer will let me know. I think of it as just a little extra saftey measure, plus having the packs balanced is never a bad thing.

edited to add: if you search on RCG, there's a thread somewhere that has diagrams that show the internal wiring of the packs with the taps. You can order the taps separately from TP, so you could add them to other non-TP packs and use the TP balancer with them as well.

Red Scholefield
09-29-2005, 03:52 PM
[QUOTE=Matt Kirsch] Hopefully someone knows what philosophy ThunderPower is using with these packs.

I suppose we will have to wait until some user digs into it and posts the information as Thunder Power has not supplied any product for magazine review by independent testors.

I have heard that AstroFlite balancer add-on to the 109 discharges individual cells until the match the voltage of the lowest cell and then proceeds to charge all the cells - based on the assuption that they all have the same charge effeciency.

FMA on the other hand, with their new SKYVOLT system, charges all the cells individually until each is at the proper full charge voltage of 4.2 volts. The also have developed software that allows you to view the charge process.

It may be downloaded from their web site if you want to check it out.

(File type: MS Install , File size: 209K)
Version 1.27 This is the 1-6S Charger viewer software that is in beta test now. Dot.Net has to be installed first. Added Indivdual Cell Capacity measurements to show how much charge is put back into each cell in the pack.

Testing so far on the SKYVOLT indicates it does as advertised. I deliberatly made up a badly unbalanced pack and it handled it with no problem.

Red Scholefield
The Battery Clinic
Model Aviation Magazine

Vamooska
09-29-2005, 04:56 PM
If you choose to add taps yourself...PLEASE excercise extreme caution! The tabs that are soldered to are in close proximity and are vulnerable to shorts.
Peace
Jeff

Red Scholefield
09-29-2005, 06:05 PM
If you choose to add taps yourself...PLEASE excercise extreme caution! The tabs that are soldered to are in close proximity and are vulnerable to shorts.
Peace
Jeff


I agree. See some pretty sad situations here at the clinic from people whose soldering expertise is limited to a torch and 3/16 dia. piano wire for landing gears. If you are not competely comfortable with soldering diode jumpers in your transmitter you should heed Jeff's advice - find a friend, that's what friends are for - to keep you from screwing up your own stuff.

nate1001
10-08-2005, 04:28 AM
the taps on tp packs are arranged so the two next to each other are for one cell. the wire colors are black, white, blue, red. the black is neg for c1 white is positive for c1 and neg for c2 blue is positive for c2 and neg for c3 and red is pos for c3

norgefreek
10-09-2005, 05:44 AM
Hey Guys Great stuff. Can anyone tell me where to find a failsafe bit of micro electronics that will stop the lipos from ever being discharged too far? Or better yet, some where with the schematics to build em. be safe ,Ivan the terrible

Red Scholefield
10-09-2005, 05:25 PM
Hey Guys Great stuff. Can anyone tell me where to find a failsafe bit of micro electronics that will stop the lipos from ever being discharged too far? Or better yet, some where with the schematics to build em. be safe ,Ivan the terrible

FMA offers a Discharge Protection Module as part of their new SKYVOLT system. They also offer an Automatic Cell Detect, Low Voltage Cutoff Device for only $20 that will prevent over discharge of LiPos.

everydayflyer
10-09-2005, 07:07 PM
Thunder Power TP-205 Smart Balancer mini review(?) here .

http://www.rcgroups.com/forums/showpost.php?p=3740435&postcount=8

Not released as yet TP-210 here.

http://www.rcgroups.com/forums/showpost.php?p=4217667&postcount=499


Charles