Can it charge two packs?
05-10-2008, 11:36 PM
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Can it charge two packs?
Is there a way I can charge two li-po packs with my 989? I got it not too long ago and like it and would rather stick with it then upgrade to a Hyperion or something that clearly states it charges two packs. I am asking because I will be purchasing a new E Revo when they are released and will be running dual li-po packs on it. Would be much faster to have the ability to charge two at once. Thanks in advance
05-11-2008, 08:44 AM
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RE: Can it charge two packs?
Yes, if the packs contain the same number of series cells (both 2S) and they are at the same state of charge (voltage) then they can be parallel charged. In fact any number of packs can be parallel charged if the voltage is same.
Connect both + together and both - together and then add the capacity of the two packs for capacity purposes.
Connect both + together and both - together and then add the capacity of the two packs for capacity purposes.
05-11-2008, 02:58 PM
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RE: Can it charge two packs?
ORIGINAL: guver
Yes, if the packs contain the same number of series cells (both 2S) and they are at the same state of charge (voltage) then they can be parallel charged. In fact any number of packs can be parallel charged if the voltage is same.
Connect both + together and both - together and then add the capacity of the two packs for capacity purposes.
Yes, if the packs contain the same number of series cells (both 2S) and they are at the same state of charge (voltage) then they can be parallel charged. In fact any number of packs can be parallel charged if the voltage is same.
Connect both + together and both - together and then add the capacity of the two packs for capacity purposes.
05-11-2008, 04:34 PM
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RE: Can it charge two packs?
Any of these parallel connectors should illustrate how to hook the two + up together and the two - together as one.
http://www.electrifly.com/miscproducts/adapters.html
Please make sure the packs are identical voltage so the current doesn't flow from the higher voltage pack.
You will now have a 4S pack that is twice as big (in capacity)
This may also help. http://www.commonsenserc.com/page.ph...po_wiring.html
http://www.electrifly.com/miscproducts/adapters.html
Please make sure the packs are identical voltage so the current doesn't flow from the higher voltage pack.
You will now have a 4S pack that is twice as big (in capacity)
This may also help. http://www.commonsenserc.com/page.ph...po_wiring.html
08-21-2008, 10:09 AM
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RE: Can it charge two packs?
[link]http://www.all-battery.com/index.asp?PageAction=VIEWPROD&ProdID=1013[/link]
Guver or Tim,
I'm gonna copy a poste I made on 2 other forums to see if I can get an answer from you as I'm using the MRC Super Brain 989 charger. I'm quoting above because this is what I'm attempting to do, charge 2 identical Lipo's hooked up in parallel, each w/ align balance connectors:
'OK, so the only Lipo batteries I found to dimensionally fit my R/C cars' receiver box are [link=http://www.all-battery.com/index.asp?PageAction=VIEWPROD&ProdID=970]these[/link]. In fact I can fit 2 of them side by side and wanted to increase my run time by wiring them in parallel to effectively get a 7.4V 2500mAh pack. The packs have align balance connectors and I could wire [link=http://www.amainhobbies.com/product_info.php/cPath/1_61_136/products_id/14575]male servo connectors[/link] on each and use a [link=http://www.amainhobbies.com/product_info.php/cPath/1_61_136/products_id/14576]Y harness [/link]to connect them to my receiver. But I want to know if I hard wired (soldered) the positive and negative terminals of each pack together and then soldered on my male servo connector to that, how would I go about charging the newly configured pack? Did i create a 2S2P pack that would be charged exactly the same as the original individual packs? What about the balance connectors, would I need 2 [link=http://www.all-battery.com/index.asp?PageAction=VIEWPROD&ProdID=1013]blinkys[/link] since my MRC super brain charger doesn't balance on its own as it charges Lipos? I'm not so familiar with Lipos so if there's an error in my plan, please LMK....'
So that's the direct quote. Also could I make/buy a y harness for the balance connectors allowing me to use the one blinky I currently own instead of buying another? I've found info on [link=http://scriptasylum.com/rc_speed/_lipo.html]wiring a balance connector when 2 packs are wired together in parallel[/link], but it'd require me to open up and re-solder my packs which I'm hesitant to do. If that's the only way to accomplish it then so be it. As long as I'm assured that there isn't any Lipo explosion/danger factor from soldering, hard wiring would be best overall, to keep resistance to a minimum from connections.
Another question I posted elsewhere concerning [link=http://forums.all-battery.com/index.php?showtopic=7391]PCB vs Voltage Regulator[/link]. Both of you guys seem to know the answers to most questions asked as I've read through most of the discussions concerning Lipos and the 989.
ORIGINAL: guver
Yes, if the packs contain the same number of series cells (both 2S) and they are at the same state of charge (voltage) then they can be parallel charged. In fact any number of packs can be parallel charged if the voltage is same.
Connect both + together and both - together and then add the capacity of the two packs for capacity purposes.
Yes, if the packs contain the same number of series cells (both 2S) and they are at the same state of charge (voltage) then they can be parallel charged. In fact any number of packs can be parallel charged if the voltage is same.
Connect both + together and both - together and then add the capacity of the two packs for capacity purposes.
I'm gonna copy a poste I made on 2 other forums to see if I can get an answer from you as I'm using the MRC Super Brain 989 charger. I'm quoting above because this is what I'm attempting to do, charge 2 identical Lipo's hooked up in parallel, each w/ align balance connectors:
'OK, so the only Lipo batteries I found to dimensionally fit my R/C cars' receiver box are [link=http://www.all-battery.com/index.asp?PageAction=VIEWPROD&ProdID=970]these[/link]. In fact I can fit 2 of them side by side and wanted to increase my run time by wiring them in parallel to effectively get a 7.4V 2500mAh pack. The packs have align balance connectors and I could wire [link=http://www.amainhobbies.com/product_info.php/cPath/1_61_136/products_id/14575]male servo connectors[/link] on each and use a [link=http://www.amainhobbies.com/product_info.php/cPath/1_61_136/products_id/14576]Y harness [/link]to connect them to my receiver. But I want to know if I hard wired (soldered) the positive and negative terminals of each pack together and then soldered on my male servo connector to that, how would I go about charging the newly configured pack? Did i create a 2S2P pack that would be charged exactly the same as the original individual packs? What about the balance connectors, would I need 2 [link=http://www.all-battery.com/index.asp?PageAction=VIEWPROD&ProdID=1013]blinkys[/link] since my MRC super brain charger doesn't balance on its own as it charges Lipos? I'm not so familiar with Lipos so if there's an error in my plan, please LMK....'
So that's the direct quote. Also could I make/buy a y harness for the balance connectors allowing me to use the one blinky I currently own instead of buying another? I've found info on [link=http://scriptasylum.com/rc_speed/_lipo.html]wiring a balance connector when 2 packs are wired together in parallel[/link], but it'd require me to open up and re-solder my packs which I'm hesitant to do. If that's the only way to accomplish it then so be it. As long as I'm assured that there isn't any Lipo explosion/danger factor from soldering, hard wiring would be best overall, to keep resistance to a minimum from connections.
Another question I posted elsewhere concerning [link=http://forums.all-battery.com/index.php?showtopic=7391]PCB vs Voltage Regulator[/link]. Both of you guys seem to know the answers to most questions asked as I've read through most of the discussions concerning Lipos and the 989.
08-21-2008, 10:35 AM
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RE: Can it charge two packs?
If I understand you then you'd like to hard wire the two packs together at the main leads to use your two pin rx plug. That should work just fine and it should also eliminate the need for the rx Y-harness , right?
Or you would put the rx plug on each one and Use the Y harness to make the parallel connection itself. That works too , and is better for isolating and future trouble-shooting. It could be potential connection problems with one pack not being used and you not recognizing it until late in the run when one pack is empty and other pack is full.
In either case the pack is a 2S 2500 and can be charged twice as fast as one single pack.
For the balance plug , I suppose you can use 1 blinky on one pack at a time toward the end of the charge (during the cv stage) Plug into one pack's balance tap to balance and when it's done plug into the other pack's balance tap. The two balance taps can also be paralleled together externally with a Y connector or hard wired to only one plug so the blinky can balance them both at same time.
sorry can't help with the pcb or regulator.
Or you would put the rx plug on each one and Use the Y harness to make the parallel connection itself. That works too , and is better for isolating and future trouble-shooting. It could be potential connection problems with one pack not being used and you not recognizing it until late in the run when one pack is empty and other pack is full.
In either case the pack is a 2S 2500 and can be charged twice as fast as one single pack.
For the balance plug , I suppose you can use 1 blinky on one pack at a time toward the end of the charge (during the cv stage) Plug into one pack's balance tap to balance and when it's done plug into the other pack's balance tap. The two balance taps can also be paralleled together externally with a Y connector or hard wired to only one plug so the blinky can balance them both at same time.
sorry can't help with the pcb or regulator.
08-21-2008, 11:11 AM
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RE: Can it charge two packs?
ORIGINAL: guver
If I understand you then you'd like to hard wire the two packs together at the main leads to use your two pin rx plug. That should work just fine and it should also eliminate the need for the rx Y-harness , right?
YES
Or you would put the rx plug on each one and Use the Y harness to make the parallel connection itself. That works too , and is better for isolating and future trouble-shooting. It could be potential connection problems with one pack not being used and you not recognizing it until late in the run when one pack is empty and other pack is full.
So, which would you do, the 1st way (eliminating the rx Y-harness) or the 2nd way (using the Y harness)?
In either case the pack is a 2S 2500 and can be charged twice as fast as one single pack.
For the balance plug , I suppose you can use 1 blinky on one pack at a time toward the end of the charge (during the cv stage) Plug into one pack's balance tap to balance and when it's done plug into the other pack's balance tap. The two balance taps can also be paralleled together externally with a Y connector or hard wired to only one plug so the blinky can balance them both at same time.
Any idea where to find a y harness for the balance taps online, or parts to make it myself? Since I've effectively created a 2S2P pack is the balance connector the same regardless of whether done with a y harness or hard wired?
sorry can't help with the pcb or regulator.
No problem, I ordered 2 more regulators (for 2 more cars), just hoping the regulator doesn't get tripped up by the pack configuration. It has low voltage drop detection at 6.2V but I wonder if it can detect if one pack drops below the threshold while the other is still above it? Is each pack now going to be recognized as a 'cell', or are all 4 cells going to be recognized? I'm guessing each pack since it detects at 6.2V total, not at 3.1V for each cell, right? So I have a potential problem of creating an out of balance situation where one may be near peak(@4.2V) while the other is dangerously low(@2V)
If I understand you then you'd like to hard wire the two packs together at the main leads to use your two pin rx plug. That should work just fine and it should also eliminate the need for the rx Y-harness , right?
YES
Or you would put the rx plug on each one and Use the Y harness to make the parallel connection itself. That works too , and is better for isolating and future trouble-shooting. It could be potential connection problems with one pack not being used and you not recognizing it until late in the run when one pack is empty and other pack is full.
So, which would you do, the 1st way (eliminating the rx Y-harness) or the 2nd way (using the Y harness)?
In either case the pack is a 2S 2500 and can be charged twice as fast as one single pack.
For the balance plug , I suppose you can use 1 blinky on one pack at a time toward the end of the charge (during the cv stage) Plug into one pack's balance tap to balance and when it's done plug into the other pack's balance tap. The two balance taps can also be paralleled together externally with a Y connector or hard wired to only one plug so the blinky can balance them both at same time.
Any idea where to find a y harness for the balance taps online, or parts to make it myself? Since I've effectively created a 2S2P pack is the balance connector the same regardless of whether done with a y harness or hard wired?
sorry can't help with the pcb or regulator.
No problem, I ordered 2 more regulators (for 2 more cars), just hoping the regulator doesn't get tripped up by the pack configuration. It has low voltage drop detection at 6.2V but I wonder if it can detect if one pack drops below the threshold while the other is still above it? Is each pack now going to be recognized as a 'cell', or are all 4 cells going to be recognized? I'm guessing each pack since it detects at 6.2V total, not at 3.1V for each cell, right? So I have a potential problem of creating an out of balance situation where one may be near peak(@4.2V) while the other is dangerously low(@2V)
08-21-2008, 11:25 AM
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RE: Can it charge two packs?
I'm not sure which way I'd do it. Maybe I'd start out with using the Y harness and then if I was real sure that those are the two packs I wanted or if the connection ever got messed up then I'd go ahead and wire them direct with only one plug.
I'm not sure if ayone makes a factory Y for balance taps , but you could try these guys
http://www.maxamps.com/index.php
http://www.commonsenserc.com/product...qph1oo1e3u78e3
http://www.allerc.com/index.php?cPat...f6dbd6f62254c5
http://www.cheapbatterypacks.com/?si...gid=connectors
The balance connector would be the same result if done witha Y or wiring them (like the main connection)
The two packs will always remain in balance (as packs) and anything plugged into the main lead will see it as a 2S x 2500 pack. The 2P is meaningless really.
I'm not sure if ayone makes a factory Y for balance taps , but you could try these guys
http://www.maxamps.com/index.php
http://www.commonsenserc.com/product...qph1oo1e3u78e3
http://www.allerc.com/index.php?cPat...f6dbd6f62254c5
http://www.cheapbatterypacks.com/?si...gid=connectors
The balance connector would be the same result if done witha Y or wiring them (like the main connection)
The two packs will always remain in balance (as packs) and anything plugged into the main lead will see it as a 2S x 2500 pack. The 2P is meaningless really.
08-21-2008, 12:24 PM
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RE: Can it charge two packs?
Guver pretty much covered it. I’d do as he stated. Start with a Y harness to see if this is indeed the way you want to go. This would also allow you to easily split them up if needed, and also check the voltages of each to make sure they're still fairly close to each other. Once everything is confirmed, then I would have no problem telling you to solder the connector to make it permanent.
08-21-2008, 12:45 PM
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RE: Can it charge two packs?
Thanks guys!! I'm gonna start with the rx Y harness since I have one already and test it first. As long as everything goes as planned, I'm gonna end up hard wiring mainly because I have only one blinky for the balance connectors and a y harness for the align type balance connector isn't available commercially. The only thing I found from the sites recommended was an [link=http://www.commonsenserc.com/product_info.php?cPath=32_39&products_id=279]extension cord cable[/link] that I'd have to buy 2 of and make my parallel connection y harness. If you don't here back from me it means everything went well, my Lipo packs should arrive today and my new regulators on Monday.
08-21-2008, 07:44 PM
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RE: Can it charge two packs?
Well I'm back, so therefore problems!!! Really simple, one of my 2 packs arrived damaged, puffy from the start. Unfortunately I didn't realize something was amiss until I'd wired it up w/ connectors and opened the second one to compare. In the words of Fred Sanford, "You big dummy!". I actually thought the pack came with an air type cushioning for off road r/c use. Luckily no one was hurt by the mishap and a new one is being shipped out to me tomorrow.
08-21-2008, 08:31 PM
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RE: Can it charge two packs?
Hmm, good catch though. Can you get away with just one pack (when the other pack is out)? The Y harness makes that very easy, right? 
08-21-2008, 10:41 PM
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RE: Can it charge two packs?
Yup, one pack would've always worked, I was just wanting to get all day runnning w/o any thoughts of having to recharge during the race day. I'm going to be running 2 (buggy and truggy) if not 3 (+MT) classes during the [link=http://www.trax70.com/cgi-bin/Blah/Blah.pl?b=ORD]fall point series[/link] and won't have time in between for anything except firing up the next car.
I'm currently autocycling the good pack at mfgs recommendation of .5C charge rate and 2C discharge rate for 3 cycles. I just learned something new I thought I'd share w/ any other newbs to the SuperBrain 989....the time setting in autocycle is the time in between cycles. Yes it's stated in the manual but I always somehow managed to miss it up until now. Before my realization I was trying to calculate how much time it'd take to charge my pack.....dooohhhh! I had it set for 30 mins originally but that's crazy for Lipo's as they shouldn't heat up and therefore shouldn't need to cool down, right? After my realization I changed it to 5 mins, giving me time to be away between cycles for 'fridge runs
I've got more questions on the charger operation but am going to read through some posts to see if they've possibly already been answered. thanks again and updates will be forthcoming on my progress with the project.
I'm currently autocycling the good pack at mfgs recommendation of .5C charge rate and 2C discharge rate for 3 cycles. I just learned something new I thought I'd share w/ any other newbs to the SuperBrain 989....the time setting in autocycle is the time in between cycles. Yes it's stated in the manual but I always somehow managed to miss it up until now. Before my realization I was trying to calculate how much time it'd take to charge my pack.....dooohhhh! I had it set for 30 mins originally but that's crazy for Lipo's as they shouldn't heat up and therefore shouldn't need to cool down, right? After my realization I changed it to 5 mins, giving me time to be away between cycles for 'fridge runs
I've got more questions on the charger operation but am going to read through some posts to see if they've possibly already been answered. thanks again and updates will be forthcoming on my progress with the project.
08-22-2008, 08:19 AM
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RE: Can it charge two packs?
ORIGINAL: marshon50
I've got more questions on the charger operation but am going to read through some posts to see if they've possibly already been answered. thanks again and updates will be forthcoming on my progress with the project.
I've got more questions on the charger operation but am going to read through some posts to see if they've possibly already been answered. thanks again and updates will be forthcoming on my progress with the project.
Tim Sandor
08-22-2008, 09:54 AM
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RE: Can it charge two packs?
Thanks Tim, much appreciated!! I'll reserve the call for 911 situations, which hopefully won't occur
I do have a question on settings and readings when going through the profile setup, here's the specs when scrolling thru:
Mode: Charge
Profile:0
Type: Lipo
Cell:2
mAh:2000
Amp: 2.0
Cutoff:120Deg
Volt: 7.4
Okay so I know the 'Volt:7.4' isn't a setting, its a reading of my packs voltage. With 'Volt' flashing if I press the up arrow it reads 'Used 20'. If a press the down arrow repeatedly it scrolls thru all these different mAh and #C readings, from 2C thru 8C, with milliamps between 000 and 994. Also the last pressing of the down arrow before it starts the cycle over reads '013 mAh, 1d'. Is this the history of this charge profile and how many milliamps went in on each charge? Also what does the '#C' mean, is it for charge # and '#d' for discharge #, in my case saying I've discharged on this profile once and withdrew 013 mAh?
This isn't critical, as I can charge my Lipo's fine, I'm just trying to learn how to do and understand everything with this charger so I can be like MacGuyver![sm=wink_smile.gif]
I do have a question on settings and readings when going through the profile setup, here's the specs when scrolling thru:
Mode: Charge
Profile:0
Type: Lipo
Cell:2
mAh:2000
Amp: 2.0
Cutoff:120Deg
Volt: 7.4
Okay so I know the 'Volt:7.4' isn't a setting, its a reading of my packs voltage. With 'Volt' flashing if I press the up arrow it reads 'Used 20'. If a press the down arrow repeatedly it scrolls thru all these different mAh and #C readings, from 2C thru 8C, with milliamps between 000 and 994. Also the last pressing of the down arrow before it starts the cycle over reads '013 mAh, 1d'. Is this the history of this charge profile and how many milliamps went in on each charge? Also what does the '#C' mean, is it for charge # and '#d' for discharge #, in my case saying I've discharged on this profile once and withdrew 013 mAh?
This isn't critical, as I can charge my Lipo's fine, I'm just trying to learn how to do and understand everything with this charger so I can be like MacGuyver![sm=wink_smile.gif]
