Will bulk chaging a pack with different cell counts work?

[pwd]

First off, I just want to say how great this forum is; very knowledgeable. I've been reading posts on ES for about a year now.


EDIT: I've already received my HK LiPo packs, now I just have some questions near the bottom of this page.

I would like to build my own pack with some Lipo backs; however I am very new to this and don't have a great understanding of batteries/electrical components. I was hoping this forum could help me decide if I should build my own; or go back to a pre-made; nicely packaged battery. Here is what I currently have:

Ideally, I want to replace my Golden Motor 48V 12ah Lithium Manganese battery as it appears to have some damaged cells and is cutting out on me. The challenge for my build is that I'd like it to be as portable and simple as my GM sliding battery is and have a bit more power.
From my understanding on here: http://www.endless-sphere.com/w/index.php/Building_a_LiPo_Battery_Pack I will need the following components:
Charger/Balancer
Power Supply
a bunch of Lipo Packs
Case
some sort of low voltage cut-off
extra care to not discharge below ~3.0V and not to charge past ~4.15V

I need to meet these specs:
compact (needs to be roughly the same size as my GM pack)
simple (somehow rig up a case for bulk charging and have to ability to charge each pack for balance charging; as well as a charger that isn't too bulky)
portable - the packs need to be easily removed from bike to bring inside as I store my bike outdoors
Anderson connector to GM magic pie
max Continuous discharge of 60 amps (Dual Magic Pies on max amp setting: I can live with max continuous of 30A which would be dual Magic Pies at %50 amp setting)
absolute maximum of 59.9V (Magic Pie will not function over this amount)
something with more than 575 watt hours (what my GM pack is supposed to provide)
can it handle regen from both Magic Pie controllers?

Here is where I was going to start:
http://www.hobbyking.com/hobbyking/store/__21374__ZIPPY_Compact_5000mAh_7S_25C_Lipo_Pack.html

(7S 25C 5000mAh Zippy Compact)

Would it be possible to have 6 of those packs and wire them 2 Series X 3 Parallel?
That would give me a setup of 51.8V and 15 amp hours
This is what you would call 14S3P right?

The part I'm really lost on is the charging:
What kind of charger/balancer would I need?
Is there any that have a built in power supply?

Thanks for your time. 8)

 

[docnjoj]

I believe that the 7S plugs would fit in a Hyperion 1420i but am not sure since the plug may have to be slightly modified. The Hyperion can take 14S for both charge and balance. they have come down in price and i am seriously thinking of getting one. Many folks use 6s and series 2 of them after paralleling 3 batteries. The hyperion needs a separate power supply though. Good to see you posting again pwbset.
otherDoc
Whoops! I messaged the wrong person. Sorry pwd

 

[999zip999]

A separate supply of 12-17v volts to power the charger.

 

[motomech]

First off, I just want to say how great this forum is; very knowledgeable. I've been reading posts on ES for about a year now.

I would like to build my own pack with some Lipo backs; however I am very new to this and don't have a great understanding of batteries/electrical components. I was hoping this forum could help me decide if I should build my own; or go back to a pre-made; nicely packaged battery. Here is what I currently have:

Ideally, I want to replace my Golden Motor 48V 12ah Lithium Manganese battery as it appears to have some damaged cells and is cutting out on me. The challenge for my build is that I'd like it to be as portable and simple as my GM sliding battery is and have a bit more power.
From my understanding on here: http://www.endless-sphere.com/w/index.php/Building_a_LiPo_Battery_Pack I will need the following components:
Charger/Balancer
Power Supply
a bunch of Lipo Packs
Case
some sort of low voltage cut-off
extra care to not discharge below ~3.0V and not to charge past ~4.15V

I need to meet these specs:
compact (needs to be roughly the same size as my GM pack)
simple (somehow rig up a case for bulk charging and have to ability to charge each pack for balance charging; as well as a charger that isn't too bulky)
portable - the packs need to be easily removed from bike to bring inside as I store my bike outdoors
Anderson connector to GM magic pie
max Continuous discharge of 60 amps (Dual Magic Pies on max amp setting: I can live with max continuous of 30A which would be dual Magic Pies at %50 amp setting)
absolute maximum of 59.9V (Magic Pie will not function over this amount)
something with more than 575 watt hours (what my GM pack is supposed to provide)
can it handle regen from both Magic Pie controllers?

Here is where I was going to start:
http://www.hobbyking.com/hobbyking/store/__21374__ZIPPY_Compact_5000mAh_7S_25C_Lipo_Pack.html

(7S 25C 5000mAh Zippy Compact)

Would it be possible to have 6 of those packs and wire them 2 Series X 3 Parallel?
That would give me a setup of 51.8V and 15 amp hours
This is what you would call 14S3P right?

The part I'm really lost on is the charging:
What kind of charger/balancer would I need?
Is there any that have a built in power supply?

Thanks for your time. 8)

You could gut the GM case and fit 4 of the new compact 7S 5800 mAh inside giving you 14S 11600 mAh while retaining the fuse and switch from the GM batt.

 

[pwd]

I believe that the 7S plugs would fit in a Hyperion 1420i but am not sure since the plug may have to be slightly modified. The Hyperion can take 14S for both charge and balance. they have come down in price and i am seriously thinking of getting one. Many folks use 6s and series 2 of them after paralleling 3 batteries. The hyperion needs a separate power supply though. Good to see you posting again pwbset.
otherDoc
Whoops! I messaged the wrong person. Sorry pwd

Ah ok, good to know. So I would need a charger that can do "14S", do that sound right? Basically if have four 7S 5000mAh packs, I could charge all four at a time with a 14S charger (making two 7S2P by parralelling) ?
I don't mind spending a bit extra if it makes charging easier.

A separate supply of 12-17v volts to power the charger.

Do power supplies for RC chargers exist? What do you guys use?

You could gut the GM case and fit 4 of the new compact 7S 5800 mAh inside giving you 14S 11600 mAh while retaining the fuse and switch from the GM batt.

That would be perfect! I'd love to keep the nice sliding case/key switch.

 

[dogman dan]

Or you could do a series paralell harness type rig, and use an 8s charger.

 

[wesnewell]

All those 7s HK bricks are pretty much worthless since they split the balance leads into one 4s and one 3s instead of using one 7s balance plug. WTF were they thinking? Just plain stupid. To use with a 14s charger like the Hyperion 1420i you have to have two 7s plugs. One per 7s brick of lipo. So, you'll need to cut the 2 balance plus off and wire them to one 7s plug on each 7s brick. 7s (8 wire) plugs with wires are available on ebay so you won't have to make the connectors up, just re-wire the wires. BUT, it will be just as easy to do using separate 3s and 4s bricks, or 2s and 5s, and then tape them together. What a shame they screwed this up so bad.

 

[pwd]

Or you could do a series paralell harness type rig, and use an 8s charger.

Hmm, I did alot of reading about parallel charging/balancing last night and it seems there is no reason not to do that.

So your suggestion is basically to have something like this for the power:
http://www.progressiverc.com/parallel-6x-bare-charge-cable.html
- I would solder on the 5.5MM bullet connectors

And something like this for the balancers:
http://www.progressiverc.com/parallel-6x-balance-adapter.html
- They would all have to be 7S connectors if I were to go with 7S packs

By connecting the above harnesses/cables to a charger; the charger detects all the cells and balances correctly?

Does that seem correct? Also, when buying a charger or balance cable etc... when is says it does 8S, does that mean it will still work with anything UP TO 8S? (includes 2,3,4,5,6,7 and 8S) And a 14S charger would do anythin UP TO 14S?

All those 7s HK bricks are pretty much worthless since they split the balance leads into one 4s and one 3s instead of using one 7s balance plug. WTF were they thinking? Just plain stupid. To use with a 14s charger like the Hyperion 1420i you have to have two 7s plugs. One per 7s brick of lipo. So, you'll need to cut the 2 balance plus off and wire them to one 7s plug on each 7s brick. 7s (8 wire) plugs with wires are available on ebay so you won't have to make the connectors up, just re-wire the wires. BUT, it will be just as easy to do using separate 3s and 4s bricks, or 2s and 5s, and then tape them together. What a shame they screwed this up so bad.

So because those packs have two balance leads... I can't just plug the 3s lead the 4s lead from the same 7S pack into a 7s port? I apologize if that seems like a basic question; but I just started reading about LiPo packs the last few days and want to make sure I understand that correctly.


Thanks for all the info and suggestions so far guys; I know alot more than I did a couple days ago.

 

[Kin]

Hey, just wondering, how eager are you to spend this money? You might find more value by replacing the dud cells in your LiMn pack with some 18650 LiMn Konions, and using the money on other components.

Not sure if you considered that [It might be that your pack has just a few bad cells dragging down the rest of the system; otherwise still retain a substantial portion of it's original capacity].


Otherwise, I think people have been giving great advice, so I also say LiPo is a great option as well. Will take some time to figuring out the dimensions and setup.



Edit: To address one of your questions, about the 4s and 3s leads on the 7s batteries fitting into the regular 7s port: There are two problems with just plugging those into the 7s port. One is that the actual physical plastic blocks each have two little bars and the 4 bars of the 2 separate leads won't fit properly for the 7s connector. Also, you will find that every "n" series connector will have "n+1" wires. So a 3s lead and 4s lead will have 4 wires and 5 wires respectively. A 7s connector will have 8 wires, which is one less than the sum of the other two connectors. So that won't work. The reason why they have "n+1" leads is because you need to measure between two pins to get the voltage of an individual cell. Or, as a metaphor, you need these seven bars: ||||||| in order to measure the six spaces between them.

 

[gblast123]

I would just use the main leads on the pack and plug them together in series for the 14s, then do your own parallel connector using andersons on one end, and then two sets of bullet connectors on the other.

Use this to draw current for your bike.

I would retain usage of your balance leads and use a simple low volt meter that plugs in there when you ride.

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=7225

You can set it for 3v so that you have ample warning when your pack is running low.

You can bulk charge your pack with a standard 48V lithium charger, when it first cuts out, use the balance leads to finally top off and balance any cells.

But don't mess with the balance leads, IMHO... they give you valuable future options and balancing choices... so give yourself the option of using them in the future.

David

 

[wesnewell]

Also, when buying a charger or balance cable etc... when is says it does 8S, does that mean it will still work with anything UP TO 8S? (includes 2,3,4,5,6,7 and 8S) And a 14S charger would do anythin UP TO 14S?

So because those packs have two balance leads... I can't just plug the 3s lead the 4s lead from the same 7S pack into a 7s port? I apologize if that seems like a basic question; but I just started reading about LiPo packs the last few days and want to make sure I understand that correctly.

AFAIK, all charges will charge 2s and up to the max they support.
And no, you can't plug 2 balance connectors into a single port.
If you want to use 7s packs, I'd buy a 4s and a 3s. Connect the power wires in serial. Cut the balance plugs off each (one wire at time and don't short them out). Then solder on new 7s pigtailed plugs you can get off ebay in bulk for about a buck each. Now tape the two bricks together and you have a real 7s brick, not the bastardized HK one.

 

[pwd]

Update:

I've got my charger and power supply/LiPo packs and assorted connectors and wires on their way. Will arrive this weekend (someone is picking them up for me across the US border since I'm in Canada)

I'm sticking with the 14S3P setup using 6x 6sTurnigy 5000mAh and 3x 2sTurnigy 5000mAh packs ($321 USD including shipping)
iCharger 206B charger and eFuel 300W power-supply

6X 6S JST-XH paralell harness
6X 4mm bullet harness for charging

plan is to make some series wries to wire up the pack for discharge but I will have to reconfigure to balance charge. With 15Ah avaible; I can avoid having to charge at work and just charge once a day at home; when I'm there to keep an eye on it for safety reasons. I've also got a cycle analyst on the way to mainly use for a low voltage cut-off.

EDIT: O yeah the idea of trying to fit the packs in the GM case is pretty much out the window now.

I still have to get the actual bike finished; but it should be soon and I can't wait!

 

[pwd]

Another update + a couple questions.

Got everything together yesterday, unfortunately I had reversed the polarity coming from my new pack, and when I went to plug it into the bike; I got a huge spark and the the anderson SB50 connectors on each end went up in flames! The positive terminals on each end completely melted where the negative ones were fine.

I think my pack will be ok, I haven't tested it yet though.

My question is:

Can I bulk charge my 14S pack with an iCharger 206B+ so I can just leave everything connected? (my pack is made up of 6 6S5000mAh and 3 2S5000mAh packs giving me 14S3P or 14S 15Ah)

The discharge port on my pack will be an Anderson SB50, so I just made a connector that goes from Anderson to 4mm male bullet connections to plug into the iCharger. Does that sound logical?

 

[gblast123]

Ouch.. but I would check the controller... remember that they work on smoke.. when the smoke comes out, they stop working!!

Be real careful charging the batteries also... check the voltages first through the balance connector and individually charge each pack before trying this again.

David

 

[pwd]

I tested the voltage and the 3 series are all at an even 57V, so thats a good sign, I have yet to test the controllers though (fingers crossed). :? My plan is to check each battery pack individually (from the balancers) too, as you've suggested David.

 

[dnmun]

you need to buy a voltmeter to help figure out polarity. also why not just replace the defective limno4 cells like he said? no fire risk, easier to charge. jmho.

 

[pwd]

Hi dnum, got the polarity figured out so I don't melt any more connectors. Main reason I decided to go LiPo and not replace the bad cells was I wanted more amp delivery without damaging the cells (since I'm running two hub motors). I've got the LiPo setup and running and took it for a ride last night! Its pretty nice. 8)

My question is, can I bulk charge my 14S3P pack on the iCharger 206B?

 

[wesnewell]

My question is, can I bulk charge my 14S3P pack on the iCharger 206B?

For 14s you need 58.8V for full charge. You need the Hyperion 1420i to balance or bulk charge the whole pack at once.

 

[pwd]

My question is, can I bulk charge my 14S3P pack on the iCharger 206B?

For 14s you need 58.8V for full charge. You need the Hyperion 1420i to balance or bulk charge the whole pack at once.

I'm a bit slow ... so are you saying that the iCharger 206B cannot output the 58.8V required to bulk charge my pack?

Thanks

- Paul

 

[999zip999]

I would buy a bulk charger and use your 206b for balance charging.

 

[pwd]

So I almost got some KFF ... again. Another good reason to go for a bulk charger.

Would a BMSBattery 600 watt charger work on my setup? I've got a 14S3P made from 3 groups of: 6S+2S+6S.

 

[pwd]

bump...

 

[recumbent]

I bulk charge my 14s 3p lipo with a "BMSBattery" lipo charger, and it works excellent.

One pannier has 8s cells in parallel, and the other has 6s cells in parallel, and it all balances great for the past 4,000 kms. And it's also wired with my CA to monitor voltage and such as i charge. Hope this helps, as i did not read the whole post.

 

[dogman dan]

Re the 206 b. The key thing here is the 6. It's a charger for 6s lipo. You bought 7s cells right? so you have one more cell per pack than the 206b can charge.

If you get an I charger, it has to be capable of at least 7 cells, so the 1010B would do that. You could split the pack in half, and and charge each half. Or paralell connect the two halves with an adapter you made, and charge the whole thing as a 7s pack.

Since you currently know so little, I hope you do your bulk charging in a place that won't burn the house down.

To safely bulk charge, the best method known at this time is to use these hvc lvc boards,
http://www.methtek.com/2012/02/05/complete-hobby-king-lipo-protection-kit/
plus a charger set to your packs voltage.

 

[pwd]

I bulk charge my 14s 3p lipo with a "BMSBattery" lipo charger, and it works excellent.

One pannier has 8s cells in parallel, and the other has 6s cells in parallel, and it all balances great for the past 4,000 kms. And it's also wired with my CA to monitor voltage and such as i charge. Hope this helps, as i did not read the whole post.

Thanks, that does help. Sounds like you have a similar setup as myself.

Re the 206 b. The key thing here is the 6. It's a charger for 6s lipo. You bought 7s cells right? so you have one more cell per pack than the 206b can charge.

If you get an I charger, it has to be capable of at least 7 cells, so the 1010B would do that. You could split the pack in half, and and charge each half. Or paralell connect the two halves with an adapter you made, and charge the whole thing as a 7s pack.

Since you currently know so little, I hope you do your bulk charging in a place that won't burn the house down.

To safely bulk charge, the best method known at this time is to use these hvc lvc boards,
http://www.methtek.com/2012/02/05/complete-hobby-king-lipo-protection-kit/
plus a charger set to your packs voltage.

Thanks dogman, I bought some 6S cells and some 2S cells; the iCharger works fine for those. That lipo protection kit looks pretty neat So the HVC on the kit would server as an additional layer of protection on top of the HVC from a bulk charger?
I have been charging my packs only when I'm around to monitor them as they charge; so far so good. So is bulk charging more dangerous that when balance charging all the groups of packs? My plan with a bulk charger is to have it shut off so my 14S pack stops at about 4.12V per cell to give a bit of room.