TylerDurden
100 GW
Really.green hornet said:If LifeBatt can do it, I can do it
Harmon at least has some modecum of sociability.
The care and feeding of a123-based packs...
- Thread starter GGoodrum
- Start date
Harmon at least has some modecum of sociability.
Drunkskunk
100 GW
How to prove you have low social skills and no sense of buisness salesmanship?
Make a post like this:
Make a post like this:
green hornet said:Shhhh,
I don't want to break anybodies love affair w a1234....
but this whole a123 lovefest was out of control,
just do the math.
If LifeBatt can do it, I can do it
I'll put my cell up against a123 anytime.
I'll even do a one time offer for group purchase ~9+ each
end of posting on this
green hornet
10 mW
- Joined
- Sep 17, 2007
- Messages
- 34
soooo, you like ?
EMF
100 kW
No one can answer until you post some specs...aside from cost per amp hour.green hornet said:
TylerDurden
100 GW
I rekon that would go in "selling and surplus".
BiGH
100 kW
Hey mate,green hornet said:Shhhh,
I don't want to break anybodies love affair w a1234....
but this whole a123 lovefest was out of control,
just do the math.
If LifeBatt can do it, I can do it
I'll put my cell up against a123 anytime.
I'll even do a one time offer for group purchase ~9+ each
end of posting on this
Just as you have an opinion that may or may not be different to others. You need to let others have their opinions too. Even if others have different opinions you need to challenge them with rational arguments. if you support a product that is good over time everyone will flock to it.
green hornet
10 mW
- Joined
- Sep 17, 2007
- Messages
- 34
ok
DeeL2003
1 W
green hornet said:
Nice work Mr. Forsen. Dang you just jumped into this thread(an A123 related thread too) and started dumping on people for buying these cells, me included. Are you mad that no one's paying attention to your no-name Chinese imports on your website? I don't know maybe because it's such a freakin' eyesore to navigate through your green swamp of a website.
BTW, my A123's did not have a paper cover on them. They look like the cell on your avatar but real.
green hornet
10 mW
- Joined
- Sep 17, 2007
- Messages
- 34
Do you idiots actually think a123 gives a rats ass if you buy their cells or not ?
you make me laugh
you make me laugh
green hornet
10 mW
- Joined
- Sep 17, 2007
- Messages
- 34
a123 does have paper wrap, see oct 19 posting pic
also, please provide posting reference where an a123 rep is here on the forum
promoting their cells.
I also assume u deel are a webmaster and can do better? let's see it
And no i do not expect to sell anything to any users of this forum
also, please provide posting reference where an a123 rep is here on the forum
promoting their cells.
I also assume u deel are a webmaster and can do better? let's see it
And no i do not expect to sell anything to any users of this forum
kyakdiver
100 W
Geeeeeeeeeeeeeeeeez... I was reading this thread and learning and hearing about A123's and such and then mister super cell comes along and sets the record straight for all of us. Just an idea. Trashing someone elses product does not improve respect for yours. Features and benifits of yours verses A123's and give us real reasons to purchase your product. I for one think your a ass for suggesting that those on this forum are idiots. Have you contributed anything to the discourse other than slamming others?
EMF
100 kW
Can you imagine discussing a warranty issue with this guy? Calling potential customers idiots, talk about crapping in your own nest....
DeeL2003
1 W
And I assume you do?
:lol: Your funny.Never said I was a webmaster. But I know a crappy website when I see one. Just sell one of your elite battery packs and hire a real pro and your set. :wink:
:lol: :lol: Scary thought.
TylerDurden
100 GW
Back to A123...
We can hammer on this tangent in selling and surplus.
:lol:
We can hammer on this tangent in selling and surplus.
:lol:
Doctorbass
100 GW
Just to respond about the 40C if it is really necessary, I say YESS !
The reason is because the key is the internal resistor that is a very important caracteristic of cells.
when cells are rated with high C rate number, it is because the very low internal resistor allow to draw more current. In the case where you sont need this high current per cell, the advantage is a must anyway. the reason is that as the internal resistor is low, as the cell will stay warm or cold when drawing juice on it. Cell that have lower C rate number, usally will heat up faster and a more energy will be lost in heat... loosing precious mAh...
Read carefully the battery university chapter and you will find the same explanation.
High C rate number = lower internal resistor = less loose in heat = more energy out from the same charge.
Also, on high peak power demand like 1kW+ the cell will less suffer and dammage if it have a lower internal resistor.
It can become a chain reaction as the cell get used: using lower C cell = higher internal resistor = more heat dissipated by the cell = more dammage to it = loosing mAh = again increasing internal resistor = more more heat = less less mAh = alot more dammage
to the cell... etc
Lesson 1: choose a cell with the lower internal resistor!
lesson 2: usually, these cell have higher C rate number... their cycle life will be better!
you finally get more total kWh energy per $ in the entire life or your cell.
Doc
The reason is because the key is the internal resistor that is a very important caracteristic of cells.
when cells are rated with high C rate number, it is because the very low internal resistor allow to draw more current. In the case where you sont need this high current per cell, the advantage is a must anyway. the reason is that as the internal resistor is low, as the cell will stay warm or cold when drawing juice on it. Cell that have lower C rate number, usally will heat up faster and a more energy will be lost in heat... loosing precious mAh...
Read carefully the battery university chapter and you will find the same explanation.
High C rate number = lower internal resistor = less loose in heat = more energy out from the same charge.
Also, on high peak power demand like 1kW+ the cell will less suffer and dammage if it have a lower internal resistor.
It can become a chain reaction as the cell get used: using lower C cell = higher internal resistor = more heat dissipated by the cell = more dammage to it = loosing mAh = again increasing internal resistor = more more heat = less less mAh = alot more dammage
to the cell... etc
Lesson 1: choose a cell with the lower internal resistor!
lesson 2: usually, these cell have higher C rate number... their cycle life will be better!
you finally get more total kWh energy per $ in the entire life or your cell.
Doc
silicium
10 W
Doctorbass said:
Yes, Yes and Yes
Cell A123M1 is the best cell
Jozzer
100 kW
any one know anything about this dealer and how about this combo?
lhttp://www.rctoys.com/rc-toys-and-parts/K-2-TP-1010C-IOTA/RC-PARTS-CHARGERS-BALANCERS-POWER.html
for a 8o m1 a123 cell 66 v 9 ah set up ?!
how about these connectors
http://www.powerwerx.com/product.asp?ProdID=3821
are they useful and how ?!!
thanks
efreak
lhttp://www.rctoys.com/rc-toys-and-parts/K-2-TP-1010C-IOTA/RC-PARTS-CHARGERS-BALANCERS-POWER.html
for a 8o m1 a123 cell 66 v 9 ah set up ?!
how about these connectors
http://www.powerwerx.com/product.asp?ProdID=3821
are they useful and how ?!!
thanks
efreak
That's a wonderful dumb idea, Fetcher.fechter said:
My experience is that ganging cells together in tight parallel groups protects them from over-discharge. Your `dumb idea' coupled with appropriate parallel grouping can reduce the parts count even further.
Given enough battery `width' (parallel cells) the common pack-level cutoff can be sufficient.
Richard
here is a link regarding above
http://helifreak.com/showthread.php?t=40579
and here is a copy :
"CCCV Power Supplies as A123 chargers
I have seen that some folk are using CCCV DC bench power supplies to directly charge LiFe (aka A123) packs at up to 10A or sometimes more. This is particularly useful for larger packs (8s and above) where typical R/C chargers are not powerful enough to charge at high currents or as a much cheaper option for charging two packs at once.
It would be great to hear from the folk doing their charging this way so we can learn from their experiences.
To kick things off I will describe my understanding of how it can be done and some links to examples of these lab power supplies.
Why do this ?
Amongst the advantages of A123 cells are their ability to be charged at up to 4C (10A) and their electrical robustness such that they tolerate overvoltage without damage or risk of thermal runaway. This opens the door to using high-power CCCV power supplies to achieve high charge rates at low cost.
The electrical robustness of the M1 cells and their good tolerance for over-voltage means that the 1-2% voltage tolerance on these CCCV supplies is not a problem so long as the packs are not left on the charger once they are done.
With the kind of power supplies we are talking about you can get very high power charging of high cell-count packs, well beyond what the current crop of high-end R/C chargers can achieve, at the same or lower cost.
How does it work ?
LiXx batteries are charged with a CCCV profile. That is Constant Current for the bulk of the charge and then Constant Voltage for the topping charge. These power supplies allow you to set the current and voltage limits and behave precisely as needed for a CCCV charge profile.
For example to charge a 10s pack of A123/M1 2300mAh cells at 2C you would dial up about 36.4V/4.6A. The power supply would start driving current into the packs in CC mode holding the voltage down so long as the current was at the programmed limit (in this case 4.6A). Once the voltage on the packs reaches 36.4 the voltage limit will kick in and the supply will go into CV mode, letting the current gradually drop off. You monitor the process and stop the charge (disconnect the pack from the power supply) when the current falls below 0.1C or about 250mA for A123/M1 2300mAh cells.
What's the catch ?
* No inherent safety. The R/C chargers have clever software that tries to ensure you don't try to charge a 3s battery on a 5s setting. Here you are on your own and must be very careful to set the voltage appropriately for your packs. Setting it too high won't start a fire with A123 packs but could easily kill cells. Also the chargers have total time and total charge automatic cutoffs so even if they fail to terminate the charge for any other reason, the safety net values will stop it anyway. These power supplies will just keep pumping current into the packs so long as they are connected.
* No balancing. Unless you use a charge-through balancer you are not getting any balancing. Most people find that A123 packs only need balancing every now and then. So you can simply cycle them through a standalone balancer from time to time followed by a slow charge cycle.
* No automatic end-of-charge cutoff. The power supply will keep pumping current into the pack so it has to be monitored and turned off or the pack disconnected when the charge current has fallen to 0.1C (or sooner, say 0.2C if you want quicker charge time). If you forget and leave your pack on overnight it won't start a fire but it could get ruined and some cells might vent and go open circuit. It might be a good idea to put a kitchen timer next to the power supply set for your expected charge time plus say 10 minutes.
* No data logging. The fancy R/C chargers all have PC interfaces that can let you log and review the details of each charge cycle including individual cell voltages over time.
* No total-charge-put-back data. Unless you put a WattsUp meter (or similar device) in line with your pack you won't know how much total charge went into it.
Examples
There are some really interesting options:
Mastech HY3005D, Single 30V/5A - charge a single A123 pack up to 8s at up to 5A (USD$97)
http://cgi.ebay.com/MASTECH-VARIABLE...QQcmdZViewItem
Mastech HY3010E-3 Dual 30V/10A - charge two A123 packs at the same time (up to 8s) or a single pack up to 15s at up to 10A (USD$278 + shipping)
http://cgi.ebay.com/MASTECH-TRIPLE-D...QQcmdZViewItem
Mastech HY5005-2 Dual 50V/5A - charge two A123 packs at the same time (up to 13s) or a single pack up to 26s at up to 5A (USD$230 + shipping)
http://cgi.ebay.com/NEW-MASTECH-DC-P...QQcmdZViewItem
Mastech HY5020E, Single 50V/20A - charge a single A123 pack up to 13s at up to 20A (USD$258)
http://shop.vendio.com/Evan2002/item.../?s=1184234402
=====================
OK so now over to you innovators out there that are doing this ? What have you learned ?
__________________
Kenneth
* TRex450CF/430L/12t/BLG25/HS65mg/L2100T+HS81/KP 3s 2200 25C
Previous rides: HX242, W5-4, TRex450(HDE), TRex450(SE), QJ-EP8v2, BCX2 ,Logo10
SIM: FMS, Phoenix (previously also Reflex/XTR, ClearView)
i
"
i sure like the sound of that.
efeak
http://helifreak.com/showthread.php?t=40579
and here is a copy :
"CCCV Power Supplies as A123 chargers
I have seen that some folk are using CCCV DC bench power supplies to directly charge LiFe (aka A123) packs at up to 10A or sometimes more. This is particularly useful for larger packs (8s and above) where typical R/C chargers are not powerful enough to charge at high currents or as a much cheaper option for charging two packs at once.
It would be great to hear from the folk doing their charging this way so we can learn from their experiences.
To kick things off I will describe my understanding of how it can be done and some links to examples of these lab power supplies.
Why do this ?
Amongst the advantages of A123 cells are their ability to be charged at up to 4C (10A) and their electrical robustness such that they tolerate overvoltage without damage or risk of thermal runaway. This opens the door to using high-power CCCV power supplies to achieve high charge rates at low cost.
The electrical robustness of the M1 cells and their good tolerance for over-voltage means that the 1-2% voltage tolerance on these CCCV supplies is not a problem so long as the packs are not left on the charger once they are done.
With the kind of power supplies we are talking about you can get very high power charging of high cell-count packs, well beyond what the current crop of high-end R/C chargers can achieve, at the same or lower cost.
How does it work ?
LiXx batteries are charged with a CCCV profile. That is Constant Current for the bulk of the charge and then Constant Voltage for the topping charge. These power supplies allow you to set the current and voltage limits and behave precisely as needed for a CCCV charge profile.
For example to charge a 10s pack of A123/M1 2300mAh cells at 2C you would dial up about 36.4V/4.6A. The power supply would start driving current into the packs in CC mode holding the voltage down so long as the current was at the programmed limit (in this case 4.6A). Once the voltage on the packs reaches 36.4 the voltage limit will kick in and the supply will go into CV mode, letting the current gradually drop off. You monitor the process and stop the charge (disconnect the pack from the power supply) when the current falls below 0.1C or about 250mA for A123/M1 2300mAh cells.
What's the catch ?
* No inherent safety. The R/C chargers have clever software that tries to ensure you don't try to charge a 3s battery on a 5s setting. Here you are on your own and must be very careful to set the voltage appropriately for your packs. Setting it too high won't start a fire with A123 packs but could easily kill cells. Also the chargers have total time and total charge automatic cutoffs so even if they fail to terminate the charge for any other reason, the safety net values will stop it anyway. These power supplies will just keep pumping current into the packs so long as they are connected.
* No balancing. Unless you use a charge-through balancer you are not getting any balancing. Most people find that A123 packs only need balancing every now and then. So you can simply cycle them through a standalone balancer from time to time followed by a slow charge cycle.
* No automatic end-of-charge cutoff. The power supply will keep pumping current into the pack so it has to be monitored and turned off or the pack disconnected when the charge current has fallen to 0.1C (or sooner, say 0.2C if you want quicker charge time). If you forget and leave your pack on overnight it won't start a fire but it could get ruined and some cells might vent and go open circuit. It might be a good idea to put a kitchen timer next to the power supply set for your expected charge time plus say 10 minutes.
* No data logging. The fancy R/C chargers all have PC interfaces that can let you log and review the details of each charge cycle including individual cell voltages over time.
* No total-charge-put-back data. Unless you put a WattsUp meter (or similar device) in line with your pack you won't know how much total charge went into it.
Examples
There are some really interesting options:
Mastech HY3005D, Single 30V/5A - charge a single A123 pack up to 8s at up to 5A (USD$97)
http://cgi.ebay.com/MASTECH-VARIABLE...QQcmdZViewItem
Mastech HY3010E-3 Dual 30V/10A - charge two A123 packs at the same time (up to 8s) or a single pack up to 15s at up to 10A (USD$278 + shipping)
http://cgi.ebay.com/MASTECH-TRIPLE-D...QQcmdZViewItem
Mastech HY5005-2 Dual 50V/5A - charge two A123 packs at the same time (up to 13s) or a single pack up to 26s at up to 5A (USD$230 + shipping)
http://cgi.ebay.com/NEW-MASTECH-DC-P...QQcmdZViewItem
Mastech HY5020E, Single 50V/20A - charge a single A123 pack up to 13s at up to 20A (USD$258)
http://shop.vendio.com/Evan2002/item.../?s=1184234402
=====================
OK so now over to you innovators out there that are doing this ? What have you learned ?
__________________
Kenneth
* TRex450CF/430L/12t/BLG25/HS65mg/L2100T+HS81/KP 3s 2200 25C
Previous rides: HX242, W5-4, TRex450(HDE), TRex450(SE), QJ-EP8v2, BCX2 ,Logo10
SIM: FMS, Phoenix (previously also Reflex/XTR, ClearView)
i
"
i sure like the sound of that.
efeak
I still prefer a separate charger per cell to insure each gets a full charge. Much better balancing than the R/C way.
Perhaps a mass charger for constant current -- then charger per cell for constant voltage.
An inexpensive, high-current single-cell charger is still the ultimate. I like the flexibility and guarantee of full, balanced charge every time.
Richard
Perhaps a mass charger for constant current -- then charger per cell for constant voltage.
An inexpensive, high-current single-cell charger is still the ultimate. I like the flexibility and guarantee of full, balanced charge every time.
Richard
silicium
10 W
News on my BMS 'home made' for 12...15S A123M1.
The circuit is ended and work fine.
The charge start at 8A and ended at 3A. Balancing at 300 mA.
The discharge cutoff voltage is 2.3V for all cells (first cell discharging cut the battery)
a vidéo on charge end and balancing is here:
http://fr.youtube.com/watch?v=-IbUOpl2PMI
View balancing (5 cells balancing yet)
The circuit is ended and work fine.
The charge start at 8A and ended at 3A. Balancing at 300 mA.
The discharge cutoff voltage is 2.3V for all cells (first cell discharging cut the battery)
a vidéo on charge end and balancing is here:
http://fr.youtube.com/watch?v=-IbUOpl2PMI
View balancing (5 cells balancing yet)
Doctorbass
100 GW
Wow super silicium! great job!
How did you pay for building a complete circuit kit?? is that the final version? alpha, beta... etc
What do you use for the power supply?
Doc
How did you pay for building a complete circuit kit?? is that the final version? alpha, beta... etc
What do you use for the power supply?
Doc