Noob Lipo Dummy (need a Lot of help)

[RallySTX]

TC, I sent you a pm, and I don't think one string of two batteries will get you very far. Remember, don't overcharge, don't overdraw, and don't forget to grin. Brian L.

[EBJ]

The question is do you hook up the batteries in series first then paralleled, like you did, or do you hook them up parallel first?
I am new to this and have wondered about that question not sure what the Correct answer is , but I know what works for me.

i think the main reason hook up their packs in parallel first is for ease of balancing.
When hooked in parallel, the balance tabs can also be hooked in parallel. So 3 batteries hook up in parallel would alow thoe three batteries to share just one balance tab, allowing you to charge and balance all three of those packs as one really large Ah pack. Example: Hooking up three 5Ah (5,000mah) packs in parallel, and connecting the balance tabs in parallel as well, when plugged into the charger it sees it as a 15Ah pack. (and balances the cells (grouped in threes now) accordingly)

[TopCat]

TC, I sent you a pm, and I don't think one string of two batteries will get you very far. Remember, don't overcharge, don't overdraw, and don't forget to grin. Brian L.

Hi Brian,

I got your PM but it was after I seen this post. In your little pic there areonly 4 batts, im planning on using 6. I'll let you use your little pic setup on your bike first and wait for the results.
Your probably right that 1 string of 6 batts wont get me very far BUT a string of 6 batts will get me a lot further than the 2 iv'e been using for months

As to the lead/charging harness you linked to on EP buddy....

4mm Bullet Conector Parallel Charge Cable.

"This power cable is used for charging up to six batteries with 4mm bullet connectors in parallel.
Made of quality 12 gauge and 14 gauge flexible silicone rubber wires."
http://epbuddy.com/index.php?main_page=product_info&products_id=165

Would I also need to get a balance lead/harness as well? and hook both leads/harnesses up to all my 6 batts to charge and balance them?

5S JST-XH Parallel Balance Cable X6.

"This cable is used for parallel charging up to six 5S LiPo batteries with JST-XH balance plugs."
http://epbuddy.com/index.php?main_page=product_info&cPath=26_14&products_id=57

Im still waiting to see if any experts will post and let me know if the setup I planned on using will work or blow me up?



Note- All batts in above picture will be fully charged up before hooking up to the leads. This setup is NOT repeat NOT for charging up the batts but for running my bike at 36V for longer range.

Regards
Tom

[mattetjus]

hey TC,

It will work, BUT, as i understand it (anyone feel free to correct me):

in case that the battery cells are not equally strong, e.g. capacity differs slightly between the individual cells, they may go out of balance.

A rule of thumb it is to parallel lithium cells first, then put them in series;

as you have the packs in your figure, (i'll name your cells, from left to right, A1, A2; B1, B2; C1, C2, attached png-picture) , I'll call this
---
CASE A
---
you have the two packs A1 and A2 in series (likewise, B1+B2 and C1+C2) and these will then be paralleled with the B's and C's;
When/if a cell in e.g. A1 goes bad, as in internal short circuit or something, or if it simply runs out of juice before the others; the B1+B2 and C1+C2 strings will have higher potential than A1+A2 and will discharge some of their capacity through A1+A2, meaning: all cells in B1, B2, C1 and C2 may go below their acceptable Low Voltage.

---
CASE B
---
Now, if keeping the cells paralleled (for you, this could be, connecting the balancing cables of A1+B1+C1 together, and likewise A2+B2+C2), you will 'only' endanger 3 cells in the case of a single bad cell.


for example, Cell 1 in pack A1 goes bad:
in your figure, potentially all the cells in B1, B2, C1, C2 could go below their preferred Low Voltage Cut Off -- 4 of 6 packs may go completely dead + pack A1 lost 1 of its cells.
If paralleled first, you'd discharge the first cells in B1 and C1 through the bad cell in A1 -> you now have 3 of 6 packs which have one bad cell each. (a bit better than the risk of 4 completely dead packs)

[TopCat]

hey TC,

It will work, BUT, as i understand it (anyone feel free to correct me):

in case that the battery cells are not equally strong, e.g. capacity differs slightly between the individual cells, they may go out of balance.

A rule of thumb it is to parallel lithium cells first, then put them in series;

as you have the packs in your figure, (i'll name your cells, from left to right, A1, A2; B1, B2; C1, C2, attached png-picture) , I'll call this
---
CASE A
---
you have the two packs A1 and A2 in series (likewise, B1+B2 and C1+C2) and these will then be paralleled with the B's and C's;
When/if a cell in e.g. A1 goes bad, as in internal short circuit or something, or if it simply runs out of juice before the others; the B1+B2 and C1+C2 strings will have higher potential than A1+A2 and will discharge some of their capacity through A1+A2, meaning: all cells in B1, B2, C1 and C2 may go below their acceptable Low Voltage.

---
CASE B
---
Now, if keeping the cells paralleled (for you, this could be, connecting the balancing cables of A1+B1+C1 together, and likewise A2+B2+C2), you will 'only' endanger 3 cells in the case of a single bad cell.


for example, Cell 1 in pack A1 goes bad:
in your figure, potentially all the cells in B1, B2, C1, C2 could go below their preferred Low Voltage Cut Off -- 4 of 6 packs may go completely dead + pack A1 lost 1 of its cells.
If paralleled first, you'd discharge the first cells in B1 and C1 through the bad cell in A1 -> you now have 3 of 6 packs which have one bad cell each. (a bit better than the risk of 4 completely dead packs)

Hi mattetjus, thanks for the input. I'll do another diagram in paint just to make sure I got it right before I go making any leads. Until then i'll just need to do what ianmacnally2 suggested

just take one of those packs in series instead of all three and run your bike on that. bring the extra pack in your bag and switch them out,

. Of course that would also mean taking a screwdriver with me to open the big gray box on my bike and swap out the batts.


Regards
Tom

[TopCat]

I done another diagram, hopefully someone will chip in and tell me if this is right?

6 Turnigy 5000mAh 5S 25C Lipo Packs wired to give 36v for more range on my bike.



Regards
Tom

[docnjoj]

Yep! Much better. Parallel first then series. Those series wires should be maybe at least 10 ga. depending on the amp draw you desire and the speed you want.
otherDoc

[RallySTX]

I don't think the drawing is correct. I hope I'm wrong but the easy way to tell is to check the controller leads with a voltmeter when it's done.
Brian L.

[mattetjus]

yeah, the drawing is a bit hard to decrypt

Hope this helps:
rename B1 -> A3, B2-> B1, C1 -> B2, C2 -> B3: A1-3 and B1-3
Connect First three packs in parallel (incl. balance cables), connect last three packs in parallel and then do the two paralleled blocks in series (see fig.)

[docnjoj]

Oops! On closer inspection it looks like the 2 sets of 3 are also in parallel. Perhaps make it simple with 3 packs side by side in parallel x 2 and then series wire the 2 sets to get the 44 volts. For parallel all the + leads and all the - leads should be together. Then put the 2 sets of 3 in series.
otherDoc.

[RallySTX]

TC, if you haven't blown yourself up yet! I will redo my little drawing for you, so you can see what I was driveing at. I need to wait til tomorrow to do it, cause my desktop pc died Thursday and that took all my files down with it. This laptop has a touchy mousepad. No good at all for design work. And the mouse for the pc was a ps2, and this laptop is usb. basically just use your original design, but don't forget the polarity of the strings. All you need though is to visualise one more vertical pair of batteries wired up like the second vertical string and you have the design I am on about.




Brian L.

[RallySTX]

Sorry about the crude drawing but there is what I meant. I added it to my last post.
Brian L.

[TopCat]

Hi Brian,

Looks like I have 2 different options of wiring up my lipos to get a 36v longer range battery.

Mattetjus has come up with this version....



And you have come up with this version...



are both options different - its 5.00am and im still half asleep is there one option better than the other?

No fear Brian, I haven't blown myself or anything else up yet. I'll need to send of for more connectors before I start making up any leads. I just want to get this setup right before I make anything up. That way I will hopefully have it right first time and not have to redo it over and over again until it is right.

Regards
Tom

[RallySTX]

Actually TC we both drew the same thing, they just look different. The circuit is the same. He just layed all the bbatteries in a line, and I stacked them to conform to the visual idea of rows. His drawing presumes that you know that the connections are color coded and do not hook up to the other horizontal line. Proper design rules state that each connection should be represented by a round ball at the point of contact. Thus wires crossing each other without that ball are presumed to simply be passing over each other. That's why I drew mine as a layout of a simple pack, with no crossed wires, because I have trouble getting paint to cooperate, and most folks don't care about electrical drafting, they just want it to work! So there you have it, two guys that say the same thing. This is how the harness I showed you is set up, and how I plan to build the big one for my Spoiler. Happy day to ya, I'm going to bed now!
Brian L.

[RallySTX]

Two more ways to look at the same circuit.



and finally



Brian L.

[TopCat]

Have I buggered up 2 of my lipos?

Iv'e been riding around with 6 batts in my box but only 2 are hooked up at any one time. When they run out I swap them out for another 2. Lastnight I had 2 batts in my box while I was charging the others. The 2 batts in my box were hooked up to my Turnigy watt meter and I forgot about them, this morning I went to try charging them up but no joy? Any type of charge I try comes up with LOW VOLTAGE on my ICharger 1010B+. Have I buggered up 2 of my batts by leaving them hooked up all night? .... or is there any way to rescue them? There new batts and have only been charged up 3 times.

Regards
Tom

[AussieJester]

Have I buggered up 2 of my lipos?

We don't know have you?

I certainly hope after 3 pages of instruction on how to connect and charge your LiPOs
you didn't get it wrong ..... my initial post might have been better advice after all :-S

KiM

[TopCat]

Ha ha Kim, I pressed the wrong button --- Submit instead of Preview once i'd done the post header

Regards
Tom

[AussieJester]

Ha ha Kim, I pressed the wrong button --- Submit instead of Preview once i'd done the post header

Regards
Tom

So whats the story ToPCaT whats up with the LiPO? Over charge them over discharge them make fire come from them? LoL

KiM

[TopCat]

So whats the story ToPCaT whats up with the LiPO? Over charge them over discharge them make fire come from them? LoL
KiM

Iv'e probably over discharge them by leaving them hooked up to my watt meter all night

Regards
Tom

[RallySTX]

That's a big no no Tom, time to slap ya up now. We warned ya about that. Put em on the charger alone in a fireproof bag, and try to trickle charge them in short bursts, checking the voltage after each charge. If no progress shows, they are toast. Be extremely careful watching for puffing or smoke, as this is the warning sign of impending doom. You're lucky they didn't reverse polarize and fry the bike. I think that's the solution, check with Liveforphysics or Ypedal or someone with more experience, but I believe that's the solution. Neglecting your lipo's already, shame on you!
Brian L.

[RallySTX]

I'm gonna drag this out a bit for safety's sake. After studying a bit I found that Devrees who is an established member had this to say about discharged cells.

Absolutely NEVER Exceed 4.3v/cell, never Discharge below 2.7v/cell, never puncture the cells.

With other cells, they often give warnings similar to that, and you can break the rules as much as you want, and suffer nothing, or maybe a little drop in cell capacity. LiPo is NOT like other batteries in this regard, when you break the golden rule, often even just one time, you are effectively telling the battery to fail into a ball of fire.

If you wish to use LiPo, you MUST follow that rule. No exceptions here. No room for error. No Oops, my charger reset, no excuses.

The most simple way to follow that rule is to use the wide range of awesome microprocessor controlled chargers made for LiPo batteries. They will never let the first part of the rule be broken.

For the second part of the rule, you need to watch your pack voltage while riding, or setup a LVC if you are the forgetful type. If you do ever deep discharge a cell, you are in no immediate danger. As long as the cell doesn't reverse polarity it wont explode just from excessive discharge. However, when you go to re-charge that cell, this is when you will see the fireworks. If you want to attempt to re-charge a deep discharged cell, do it in an area that you wouldn't mind making a bonfire. Maybe invite buddies over to watch. You can always stab it to make it go off if it doesn't go by itself. A deep discharged cell should never be trusted again in a string with good cells.

viewtopic.php?f=14&t=22949

Read from the link above for more data.
Brian L.

[AussieJester]

If you have read all the info on lipo in the battery section and are still struggling to come to terms with basics, it worries me a little you buying lithium polymer, perhaps lifepo4 would be more suited in this case, a Lifp04 Ping pack would suit yur setup and be alot easier to manage. lithium polymer can be dangerous if you don't have at least some basic knowledge and understanding of their requirements.
KiM

^^I stand by my first post in this thread i had a bad feeling about recommend LiPO from the start ^^

Your packs are likely damaged and thus unusable
if you wish to try charging them you could try
charging each cell individually with a
something like a mobile phone charger for example..

KiM

EDiT: I just gotta ask to, why are you only using 2 packs in your bike at a time? Why dont you parallel or parallel and series all the packs, charge them all at once and use all of them on the bike?

[BikeFanatic]

"LOW VOLTAGE on my ICharger 10"

I get that error message when I have even slightly overdischarged the batteries. I think you can charge them up slowly on the lower setting supervised.

Do you know what the individual cell voltages are? you only left it hooked to the watt meter so it slowly discharged the batts, I think there is hope.

One way to recharge the pack is to charge it at 5 series setting ( if you are using six series batteries)
and charge at low current say 0.5 AMPS, for a few minutes. watch your pack bump up to 3.75 volts per cell and then switch over to 6 series charging. charge the pack where you can keep an eye on it
feeling for heat. outside would be best.

When I was new to lipo I over discharged on pack to death, the others all came back with this method.

[dogman]

Yeah you wrecked em. Never trust em again, if they went below or above the stated numbers previously said. Check the voltage though, and if none of the cells got below 3v, then charge it up and keep going. Mark em so you know which ones it was. Bet they don't last as long as the others.

You might need to do something awkward to get em charged, like the post above says.

And paralell them to ride, duuuuh.