Going LiPo - Advice Required
- Thread starter kudos
- Start date
A question about the icecube solution.
Whats the different between the normal _series_ charge that one do with those Hyperion charger and the _parallel_ charging solution that icecube provide?
Is one safer than the other?
Does the parallel balance it better or something?
Whats the different between the normal _series_ charge that one do with those Hyperion charger and the _parallel_ charging solution that icecube provide?
Is one safer than the other?
Does the parallel balance it better or something?
NeilP
1 GW
If you have a Hyperion or icharger or any other type of hobby charger, they can only handle a certain number of cells in series..8 10 maybe 14.
So if you have a pack of 20 series...your charge won't charge it, so you have to break the pack apart, check the balance of each string of 10, make sure both strings are similar voltages across all the cells, connect the in parallel and them charge them with the hobby charger...
Or if you do not parallel them, you have to charge each pack separately
if you have a bulk charge solution..(Meanwell or BMS Alloy shell charger or any other current limited supply ..IE a string of PC power supplies ) then you do not have to mess with the config of the pack at all.
You set your bulk charge power supply to what ever you want the final voltage of your pack to be, . unplug the pack from the controller and plug in to the charger. The use any means you have to manually check the balance of each cell or block of parallel cells..this could be a voltmeter a Battery Medic or cell log..choice is yours
So if you have a pack of 20 series...your charge won't charge it, so you have to break the pack apart, check the balance of each string of 10, make sure both strings are similar voltages across all the cells, connect the in parallel and them charge them with the hobby charger...
Or if you do not parallel them, you have to charge each pack separately
if you have a bulk charge solution..(Meanwell or BMS Alloy shell charger or any other current limited supply ..IE a string of PC power supplies ) then you do not have to mess with the config of the pack at all.
You set your bulk charge power supply to what ever you want the final voltage of your pack to be, . unplug the pack from the controller and plug in to the charger. The use any means you have to manually check the balance of each cell or block of parallel cells..this could be a voltmeter a Battery Medic or cell log..choice is yours
Allex
100 MW
Btw, what would the cut off voltage be for the nano-tech lipo cells under Load? Is it 3.0V or can I go lower?
Ordered a Hyperion 1420i and a couple of 10s nano-tech turnigy, oh this will be an interesting Christmas!
Ordered a Hyperion 1420i and a couple of 10s nano-tech turnigy, oh this will be an interesting Christmas!
NeilP
1 GW
higher, not lower
I have LVC set at 3.5v per cell on my 20 series LiPo pack, using 10s Nano Tech packs (20s4p)
I have a 20 Ah pack, and on my every day riding, try to take more than about 14Ah out. I think the recommendation is 80% discharge absolute max.
When you get your packs and charger, do some logged charge/discharge cycles, and look at the graphs produced
These are turnigy nano tech 5 Ah 10s 25C-50C packs
By the time the cells get down to below 3.7volts they really start to go way out of balance.
For me 3.7 is absolute minimum. If my 20 series back (that I charge to 4.15 per cell 83 volt hot) gets down to about 75 volts I start to think I should be home.
I have just checked back ( i keep a log of all Cycle Analyst figures for every cycle)...83 volts down to a end of 74 volts gives about 13 to 14 Ah...you start going much below that and you will need balancing every few charges.
If you find yourself getting to more than half your capacity every day, I reckon you will need to make up a bigger Ah pack
I have attached my spreadsheet of all my figures for you to see if you are interested. Half way down you will see I added an extra 4s4p pack to take it up to 100 volts
View attachment 1
Here is a fuller discharge graph of a Turnigy Hardcase 4s pack
I have LVC set at 3.5v per cell on my 20 series LiPo pack, using 10s Nano Tech packs (20s4p)
I have a 20 Ah pack, and on my every day riding, try to take more than about 14Ah out. I think the recommendation is 80% discharge absolute max.
When you get your packs and charger, do some logged charge/discharge cycles, and look at the graphs produced
These are turnigy nano tech 5 Ah 10s 25C-50C packs
By the time the cells get down to below 3.7volts they really start to go way out of balance.
For me 3.7 is absolute minimum. If my 20 series back (that I charge to 4.15 per cell 83 volt hot) gets down to about 75 volts I start to think I should be home.
I have just checked back ( i keep a log of all Cycle Analyst figures for every cycle)...83 volts down to a end of 74 volts gives about 13 to 14 Ah...you start going much below that and you will need balancing every few charges.
If you find yourself getting to more than half your capacity every day, I reckon you will need to make up a bigger Ah pack
I have attached my spreadsheet of all my figures for you to see if you are interested. Half way down you will see I added an extra 4s4p pack to take it up to 100 volts
View attachment 1
Here is a fuller discharge graph of a Turnigy Hardcase 4s pack
Allex
100 MW
I see, thank you!
Looking forward to test and do some logs.
Looking forward to test and do some logs.
NeilP
1 GW
I just posted a fuller graph, all the way down from 4.1 volts down to 'the cliff'.
Go back to my last message and see what I mean about 3.7 volts.
ost of the capacity is gone by then , and you only risk putting a single cell blow a critical voltage.
Yes If you have checked all your packs and can logged them all and can guarantee NONE have poor cells,then go lower. but I do not feel it is worth the risk.
My pack is $1000 USD plus. So I'd rather be safe than risk dropping a single cell below a safe voltage..then bulk charging and setting fire to the lot.
You can never have enough LiPo capacity...except when you are on fire
Go back to my last message and see what I mean about 3.7 volts.
ost of the capacity is gone by then , and you only risk putting a single cell blow a critical voltage.
Yes If you have checked all your packs and can logged them all and can guarantee NONE have poor cells,then go lower. but I do not feel it is worth the risk.
My pack is $1000 USD plus. So I'd rather be safe than risk dropping a single cell below a safe voltage..then bulk charging and setting fire to the lot.
You can never have enough LiPo capacity...except when you are on fire
Allex
100 MW
Yeah, seems pointless to go under 3.7 because it will drop fast like a stone after that anyway...
mxer
1 kW
Fantastic read and link's, I'm a little wiser now, but no where near ready yet!!!....
Still can't get my head round parrelling the balance leads, I understand why you have to do it because some chargers only have one ballance output but i thought the whole idea of the ballance leads was to keep an eye on individual cells completly seperatly ? surley parrelling balancing leads on say 2 packs of lipo's will give you a reading of two seperate cells as one ????..............one cell could read 3.6v and another at 3.0 and would show 3.6 or would it ballance them out it'self to 3.3 ??.... Am i not making sence ? Think i need to stop reading my head is spinning,......
Still can't get my head round parrelling the balance leads, I understand why you have to do it because some chargers only have one ballance output but i thought the whole idea of the ballance leads was to keep an eye on individual cells completly seperatly ? surley parrelling balancing leads on say 2 packs of lipo's will give you a reading of two seperate cells as one ????..............one cell could read 3.6v and another at 3.0 and would show 3.6 or would it ballance them out it'self to 3.3 ??.... Am i not making sence ? Think i need to stop reading my head is spinning,......
hjns
100 kW
mxer said:
Yep, that is about correct. Parallel connection of 2 cells (aka + to+ and - to -) will create one cell with the capacity of both cells, and a voltage somewhere in the middle, depending on the internal resistance, the capacity and voltage differences between those cells. For example, 2 cells of the same brand, same chemistry, and same capacity (lets say 3.7V nominal 5Ah), will have voltage about in the middle, in case they were charged differently, but not to far from each other. The highest charged cell will just discharge into the lowest charged cell, until the voltages are the same. In cells of different capacity, the highest capacity cell will change the least when equaling with the smaller capacity cell.
Just imagine two buckets of water, however placed at the same height (aka "grounded" with the "black wires"). When connecting both buckets at floor level, the water levels will equal out. With two different sizes of buckets, the water will still equal out. With more water in one, the water will redistribute until equalled out.
Therefore, it makes sense to first charge the individual cells to a set full charge (for example 4.10V), and only then start connecting them in parallel. Imagine one empty bucket, and one full bucket. The full bucket will empty very fast into the empty one. In lipo words: the fully charged lipo will discharge very fast, charging the discharged lipo at the same rate. Now, most lipos can discharge fine at a certain rate, but can only be charged at a very low rate (C-rating). In order to make sure you do not excess these limits, only parallel cells with the same voltage.
Note, that the balancing thing is really a precaution to prevent overvolting, because the charger keeps monitoring the voltage at single cell level. Therefore, if you connect a thousand cells in parallel, the charger will still see only one cell (with a huge capacity), and the balancing thing will prevent all those cells from overvolting, even if one or ten or 999 are duds.
More importantly, keeping cells in the same voltage range is very important when putting them in series. Imagine a 2S pack. Total voltage should be maximally 2x 4.10V = 8.20V. If one cell is a dud (at 0.20V), and the charger is NOT balancing on individual cell level, the charger will only see both cells as one pack of maximally 8.20V. Therefore, when charging, it is possible to overcharge the non-dud cell to 8.00V, which is a recipe for disaster. If you put cells of different capacity and different charge in series without balancing, you are heading that way.
Now, you have read about people bulk charging (without balancing). Only do so AFTER you are sure your cells are well balanced.
NeilP
1 GW
Edit ...looks like hjns got in and posted quicker than I did
yes it would balance them as 3.3 ..or thereabouts.
The charger sees each bank of parallel cells as one cell.
Various arguments on both sides, parallel the balance leads or not, some do and some do not.
the argument ( or at least the only one I can think of now) of NOT paralleling the balance leads is that if you have one duff cell, it will pul the voltage of the others in that bank of parallel cells down, and out of balance quicker
The argument FOR paralleling balance leads is that if you have one duff cell, then it does not go out of balance so quickly, as the other cells keep its voltage UP
If you do not parallel the leads and you have a pack made up of 8 packs ( 4 packs in parallel, in two blocks in series) , then when you come to check balance and balance charge...you have 8 packs to individually balance.
If you have the balance leads paralleled, then you only have two blocks to balance
The strategy I would say to use is perhaps NOT to balance the parallel leads for the first discharge or two..but do not over discharge, and keep checking the balance.
The you can see if any cells that do drop rapidly out of balance, you know you have poor cells in some or one of the packs. You then have the option of swapping that pack out for another (>>>buy more packs than you need..5 or 10 % more at least), or just say to hell with it, and parallel them up anyway and keep a close eye on that block of paralleled cells
Oh yes ...word of warning...before paralleling the packs, balance each pack individually first. if you have packs that are out of balance and you connect them up, you are going to get a lot of current flowing through those thin balance wires very quickly..you could melt the balance wires
yes it would balance them as 3.3 ..or thereabouts.
The charger sees each bank of parallel cells as one cell.
Various arguments on both sides, parallel the balance leads or not, some do and some do not.
the argument ( or at least the only one I can think of now) of NOT paralleling the balance leads is that if you have one duff cell, it will pul the voltage of the others in that bank of parallel cells down, and out of balance quicker
The argument FOR paralleling balance leads is that if you have one duff cell, then it does not go out of balance so quickly, as the other cells keep its voltage UP
If you do not parallel the leads and you have a pack made up of 8 packs ( 4 packs in parallel, in two blocks in series) , then when you come to check balance and balance charge...you have 8 packs to individually balance.
If you have the balance leads paralleled, then you only have two blocks to balance
The strategy I would say to use is perhaps NOT to balance the parallel leads for the first discharge or two..but do not over discharge, and keep checking the balance.
The you can see if any cells that do drop rapidly out of balance, you know you have poor cells in some or one of the packs. You then have the option of swapping that pack out for another (>>>buy more packs than you need..5 or 10 % more at least), or just say to hell with it, and parallel them up anyway and keep a close eye on that block of paralleled cells
Oh yes ...word of warning...before paralleling the packs, balance each pack individually first. if you have packs that are out of balance and you connect them up, you are going to get a lot of current flowing through those thin balance wires very quickly..you could melt the balance wires
mxer
1 kW
Fantastic advice guy's and all cleared up 
Some awsome do's and don't on first lipo charges as mine will be with me soon, this is great advice :wink: ....
"Silly question time" you can tell im not there yet tho by this question..........Ready ?.......Why would you want to "series" balance leads ? :?
Some awsome do's and don't on first lipo charges as mine will be with me soon, this is great advice :wink: ...."Silly question time" you can tell im not there yet tho by this question..........Ready ?.......Why would you want to "series" balance leads ? :?
mxer
1 kW
Would this be a safer option for me or is it really that simple to parrelel ballance leads eg R+R, W+Wx5, B+B ? 4 into one ....
NeilP
1 GW
Well no ..think about it..and draw a diagram of how the packs are wired if you have to ..then think about what would happen if you series'd them
It also depends exactly what you mean...they are also sort of in series because of the main discharge leads...connect them up wrong and you will get big spark and melted leads
Those boards are OK< for charging and connecting to he charger..but generally too big and waste too much space on a bike
Wait a minute and I'll find some pictures
It also depends exactly what you mean...they are also sort of in series because of the main discharge leads...connect them up wrong and you will get big spark and melted leads
Those boards are OK< for charging and connecting to he charger..but generally too big and waste too much space on a bike
Wait a minute and I'll find some pictures
wesnewell
100 GW
The point of paralleling is so each cell in the parallel group will be equal to all others in the group and they maintain equilibrium during charge and discharge. The point of balancing is to equalize all the cells or cell groups in the series. Lots of basic info here...mxer said:
http://www.rchelicopterfun.com/rc-lipo-batteries.html
http://scriptasylum.com/rc_speed/index.html
NeilP
1 GW
Ok a few pics of my pack
packs are 10s Nano Tech packs 5ah 25C-50C wired as 20 series 4 parallel (20s4p)
With G Goodrum LVC HVC parallel board and extension leads from pack to the board
With extension leads removed to try and reduce wiring bulk
In the bag
All just too much wire and bulk ..the transistors got damaged and it was just too inconvenient..so time to dump the LVC board and go with simple balance leads
Extension leads cut down and soldered up to make my own balance leads
Fitted up to the pack
packed down tighter
packs are 10s Nano Tech packs 5ah 25C-50C wired as 20 series 4 parallel (20s4p)
With G Goodrum LVC HVC parallel board and extension leads from pack to the board
With extension leads removed to try and reduce wiring bulk
In the bag
All just too much wire and bulk ..the transistors got damaged and it was just too inconvenient..so time to dump the LVC board and go with simple balance leads
Extension leads cut down and soldered up to make my own balance leads
Fitted up to the pack
packed down tighter
wesnewell
100 GW
Balance leads are just individual taps to each cell in a lipo pack. The cells in the pack are already in series. To Understand this....mxer said:
http://scriptasylum.com/rc_speed/lipo.html
mxer
1 kW
NeilP said:
Cool thanks
, I may be getting confussed I thought the only time you need ballance leads is for charging and checking individual cells, why would i need them on my bike ?
mxer
1 kW
Thanks wesnewell some more reading 
.....
WOW!!!! Neilp......That's some pack
There are a mass of wires So you needed the balance leads parrelelled ON the bike for the LVC you had fitted ?... And now you have done away with it because you diddn't like the wire situation ? and now you just have a lead for ballancing when charging ??...Thanks for the pic's
.....WOW!!!! Neilp......That's some pack
There are a mass of wires So you needed the balance leads parrelelled ON the bike for the LVC you had fitted ?... And now you have done away with it because you diddn't like the wire situation ? and now you just have a lead for ballancing when charging ??...Thanks for the pic's
NeilP
1 GW
Yes, you need them on the bije when riding. If you are paralleling them you are doing it for all the time
The LVC board acted as dual function: as an LVC board AND and parallel board
The total pack is 20s4p = 20series 4parallel,
The 20 series part is 4 lots of 5 cells in series
You will see the board has 4 sections, one for each block of 5 cells
Each of the 4 sections has 4 connections, for connecting each block of cells in parallel for the 4 parallel part of the pack
The individual packs are sold as 10 series packs, but in reality, they are just two 5 series packs in one heat shrink wrapper
The LVC Board does not monitor individual cells for low voltage, it only monitors the combined voltage of each block of 4 parallel cells
I only got rid of the board because it was too big,and probe to damage,
4 bundles of wire like the single bundle that you see in the vice replaces the paralleling section of yhe LVC Board
I now have no LVC. Function, and have to monitor the balance manually, i usually check every time I charge, just the combined output of each bundle I DO NOT take all tye bundles apart to check individual cells, they are parallel, so each block will be the same
I think you need to stop and go back and re read what we have written, and keep re reading it and the links till you understand
The LVC board acted as dual function: as an LVC board AND and parallel board
The total pack is 20s4p = 20series 4parallel,
The 20 series part is 4 lots of 5 cells in series
You will see the board has 4 sections, one for each block of 5 cells
Each of the 4 sections has 4 connections, for connecting each block of cells in parallel for the 4 parallel part of the pack
The individual packs are sold as 10 series packs, but in reality, they are just two 5 series packs in one heat shrink wrapper
The LVC Board does not monitor individual cells for low voltage, it only monitors the combined voltage of each block of 4 parallel cells
I only got rid of the board because it was too big,and probe to damage,
4 bundles of wire like the single bundle that you see in the vice replaces the paralleling section of yhe LVC Board
I now have no LVC. Function, and have to monitor the balance manually, i usually check every time I charge, just the combined output of each bundle I DO NOT take all tye bundles apart to check individual cells, they are parallel, so each block will be the same
I think you need to stop and go back and re read what we have written, and keep re reading it and the links till you understand
hjns
100 kW
NeilP said:
+1
Nice pics, Neil! You've got quite some power in there. I just settled for 20S3P 13.5Ah, because it is on my new rear rack, and the bike is keeping wanting to do wheelies. I will probably add another 20S2P in front, to balance the weight a bit more.
NeilP
1 GW
That pack was my first build of an e-bike ever, not quite year old..went straight in with LiPo, never used any other chemistry. For a few weeks, I had the motor in another frame, with the LiPo on a rear rack, but just too unstable.
They are in the frame now in a metal box. rather than hijack this thread, here they are the pics i this thread
http://endless-sphere.com/forums/viewtopic.php?f=6&t=27586
They are in the frame now in a metal box. rather than hijack this thread, here they are the pics i this thread
http://endless-sphere.com/forums/viewtopic.php?f=6&t=27586
mxer
1 kW
NeilP said:
So you don't actually have the balance harnesses plugged into anything while on the bike, The paralleling balancing harness is just for charging only....
Am getting confussed as you keep saying, i need the parrelleling harnesses on the bike, But plugged into what ????....
All i need for the bike is the silicone lead + - to the controller, ballancing plug's x4 just hang there plugged into nothing ?..
hjns
100 kW
balancing cells while on the road really is a matter of personal preference. I only connect the balance wires when charging. When on the road, I have none of the balance wires connected, only the main leads to the controller. I know others keep the parallel cells connected to each other.
mxer
1 kW
Thankyou, I get it now 
Cool, I will not be adding parralelled ballance leads to mine for ballancing on the bike (I get it now :lol: ) just add's to the mess and tbh i don't think it is that necessary, will keep an eye on em tho while charging every now and then....I'm happy now and will go away now and do some more reading Similar threads
