1. youre sayin that LiFE can be stored at 2.0v where 2.5v is powerless to the system, what about 2S it's 2.5vx2=5v then , is this still high voltage for an system? NO as stated in m earlier post they must be stored at 60% off the packs rated capacity. As I said your vehicle will stop moving when the cells see around the 2.5 volt point so no LVC is needed.
2. what about LiFE 3S result low voltage at 7.5v? correct
Is it true that these have a higher internal resistance than conventional lipo which can create issues under braking with applications close to the esc's limit and could potentially endanger the esc?
That's my understanding on A123/Lifepo cells from this article:
I just wanted to add a small comment on this type of cell. I have been running the sub-c life cells for over a yr now in my 1/12 cars. Thay have all the advantages of a lipo without the downsides. As mentioned the discharge curve is very flat, and without a doubt you know when you have reached the end of the curve; my car will suddenly go from full speed to a crawl . But I have done this many times and then recharged(approx 20 mins) and go; no ill effects. I have been charging them with my CE charger on the lipo mode with no problems, so a special charger is not required. While I dont know if this wiil ever be the cell of choice I will say that I'm very impressed with the performance and cell life. Just thought I'd interject my thoughts from the standpoint of an actuall user. Here is a pic of them in my 1/12; and of special interest to 1/12 users these fit T-bar cars .
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Ripped off by RC Tech member: BlueStreak362 6/08
Is it true that these have a higher internal resistance than conventional lipo which can create issues under braking with applications close to the esc's limit and could potentially endanger the esc?
That's my understanding on A123/Lifepo cells from this article:
Actually the Green Series cells we have have a rather low IR. And as I stated we have tested them in the Castle Monster systems under all conditions with no issues even from hard braking in an actual race in which the driver TQ'd and won 2 of the 3 mains taking the win for the weekend running the Green series packs.
Quote:
Originally Posted by chris moore
I just wanted to add a small comment on this type of cell. I have been running the sub-c life cells for over a yr now in my 1/12 cars. Thay have all the advantages of a lipo without the downsides. As mentioned the discharge curve is very flat, and without a doubt you know when you have reached the end of the curve; my car will suddenly go from full speed to a crawl . But I have done this many times and then recharged(approx 20 mins) and go; no ill effects. I have been charging them with my CE charger on the lipo mode with no problems, so a special charger is not required. While I dont know if this wiil ever be the cell of choice I will say that I'm very impressed with the performance and cell life. Just thought I'd interject my thoughts from the standpoint of an actuall user. Here is a pic of them in my 1/12; and of special interest to 1/12 users these fit T-bar cars .
You may be fine charging your packs on a Li-Po setting, but that's your business. Chargers wouldn't be made with the A123/LiFe-Po setting for no reason. To be safe and so there are no problems our Green Series packs must be charged with an approved A123/LiFe-Po charger. Charging them with any other charger will void any warranty and you do at your own risk.
I just wanted to add a small comment on this type of cell. I have been running the sub-c life cells for over a yr now in my 1/12 cars. Thay have all the advantages of a lipo without the downsides. As mentioned the discharge curve is very flat, and without a doubt you know when you have reached the end of the curve; my car will suddenly go from full speed to a crawl. But I have done this many times and then recharged(approx 20 mins) and go; no ill effects. I have been charging them with my CE charger on the lipo mode with no problems, so a special charger is not required. While I dont know if this wiil ever be the cell of choice I will say that I'm very impressed with the performance and cell life. Just thought I'd interject my thoughts from the standpoint of an actuall user. Here is a pic of them in my 1/12; and of special interest to 1/12 users these fit T-bar cars .
1. The name is not SUB-C life, But it's A123.
2. Yes you could charge Life with Lipo Balance charge but,
you will have overcharged/overvoltage As A123 per cell is 3v, but lipo is 3.6v-4.2v when it reach max balance. that will reduce the cell's life. that's why your cars goes crawl.
3. you are recharge approx 20 mins, is too slow, because you are using wrong charger's, that's why you will need, A123/LiFE Balance charge, for better performance. you could get 4mins of charge, using right A123/LiFe charger, remember 15C of charge.
Well I didn't understand one thing in this thread. Lol. So I have just grasped the concept and care of lipos though elementary at best lol. I saw these in an ad in rc car action and searched this forum and ended up her in hopes of learning about them. Though that didn't work. My questions is, as a " lipo trainer" of sorts do they offer the same speed and run times as lipos ?
Or should I just stick to lipos to get best performance.
I will be using a savage flux
If answered in that techno jargon I didn't get it
Thanks
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Traxxas Stampede (stock)
Traxxas E Revo (stock)
Last edited by rcmonster77; 07-21-2009 at 11:24 PM.
Well I didn't understand one thing in this thread. Lol. So I have just grasped the concept and care of lipos though elementary at best lol. I saw these in an ad in rc car action and searched this forum and ended up her in hopes of learning about them. Though that didn't work. My questions is, as a " lipo trainer" of sorts do they offer the same speed and run times as lipos ?
Or should I just stick to lipos to get best performance.
I will be using a savage flux
If answered in that techno jargon I didn't get it
Thanks
Speed and power come from voltage so at 6.6 volts for a 2S2P pack they are less than a Li-Po which would be at 7.4 volts. The difference isn't much so simply stepping up a tooth or two with a pinion gear can usually get your speed back to where the 7.4 volt pack had you. Another option is to run a Higher KV brushless motor. With mAh or capacity it going to be the same. A 4500 mAh Life-Po will give you the same run time as a 4500 mAh Li-Po. But for say your Savage Flux your getting a truck that is built for power. If you want to use that power and take full full advantage of it go Li-Po and don't look back. LiFe-Po packs are in no way meant nor will they replace what a li-Po can do at this time. If you want it to be insane get the 3S 5250's if you want good power but a truck that is a tad easier to control get the 6500 7.4 packs.
I jumped to 1/8th after being in nitro for a while, and bypassed lipo all together straight to A123 "Lifepo4" batterys. While the performance and cost is awesome, the fit leaves much to be desired due to round cell design...
Seeing this flat prismatic style Lifepo4 cell give me hope.
Now I just need to save enough up for a couple 4s2p
Speed and power come from voltage so at 6.6 volts for a 2S2P pack they are less than a Li-Po which would be at 7.4 volts. The difference isn't much so simply stepping up a tooth or two with a pinion gear can usually get your speed back to where the 7.4 volt pack had you. Another option is to run a Higher KV brushless motor. With mAh or capacity it going to be the same. A 4500 mAh Life-Po will give you the same run time as a 4500 mAh Li-Po. But for say your Savage Flux your getting a truck that is built for power. If you want to use that power and take full full advantage of it go Li-Po and don't look back. LiFe-Po packs are in no way meant nor will they replace what a li-Po can do at this time. If you want it to be insane get the 3S 5250's if you want good power but a truck that is a tad easier to control get the 6500 7.4 packs.
Jason
Thanks alot
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Traxxas Stampede (stock)
Traxxas E Revo (stock)
I found these battery packs quite interesting, when I saw them advertized. I'm checking this thread out for more information, but I still have some questions.
1) I would still need a balancer to charge these, correct?
2) I am not sure my current chargers have program for these LiFe cells. I do have LiPo and Li Ion programs, but I'm guessing these won't work with the LiFe cells.
3) I see you guys offer various voltage LiFe cells. Are the 6.6 volt packs the same size as compable NiMh 6 cells packs? How about the 9.9 cell LiFe packs? Similar in size to a 7 or 8 cell NiMh pack?
I'm not crazy about LiPo packs just yet, but these LiFe cells seem nice, despite a lower voltage. I already read about better discharge voltage curves. I have no idea what a 6 cell NiMh pack drops down to under load, but would a 6.6 volt LiFe pack maintain it's loaded voltage better, thus giving comparable performance?
I wouldn't buying into these packs, but I'm not ready to buy new chargers just run them, and if I can't easily fit a 9.9 volt LiFe pack into the same kind of places a 6 to 8 cell pack fits, then I guess I'll just stick the NiMh cells.
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You have a rodent infestation. Shall I terminate?
I found these battery packs quite interesting, when I saw them advertized. I'm checking this thread out for more information, but I still have some questions.
1) I would still need a balancer to charge these, correct?
2) I am not sure my current chargers have program for these LiFe cells. I do have LiPo and Li Ion programs, but I'm guessing these won't work with the LiFe cells.
3) I see you guys offer various voltage LiFe cells. Are the 6.6 volt packs the same size as compable NiMh 6 cells packs? How about the 9.9 cell LiFe packs? Similar in size to a 7 or 8 cell NiMh pack?
I'm not crazy about LiPo packs just yet, but these LiFe cells seem nice, despite a lower voltage. I already read about better discharge voltage curves. I have no idea what a 6 cell NiMh pack drops down to under load, but would a 6.6 volt LiFe pack maintain it's loaded voltage better, thus giving comparable performance?
I wouldn't buying into these packs, but I'm not ready to buy new chargers just run them, and if I can't easily fit a 9.9 volt LiFe pack into the same kind of places a 6 to 8 cell pack fits, then I guess I'll just stick the NiMh cells.
1) Yes a balancer is still required to charge these packs.
2) Your charger must state that it will do either A123 or Life-Po cells. That is the setting that must be used.
3) All the life packs have the same foot print as a 6 cell NimH pack. As the capacity increases the packs get taller.
You can't really compare the load on a 6.6 volt pack to a 7.2 volt pack, your talking about two different pack voltages. If they had the same voltages then a comparison could be done. These are not are not a replacement for Li-Po's there a stepping stone for those that want Li-Po like performance but with out the worries.
1) Yes a balancer is still required to charge these packs.
2) Your charger must state that it will do either A123 or Life-Po cells. That is the setting that must be used.
3) All the life packs have the same foot print as a 6 cell NimH pack. As the capacity increases the packs get taller.
You can't really compare the load on a 6.6 volt pack to a 7.2 volt pack, your talking about two different pack voltages. If they had the same voltages then a comparison could be done. These are not are not a replacement for Li-Po's there a stepping stone for those that want Li-Po like performance but with out the worries.
Jason
Understood, and thanks! You guys still have great customer service, I see.
So it looks like I would need a new battery charger, as my Team Checkpoint TC-1030 doesn't have an A123 cell program. At least I don't think it does.
On question 3, if I understand correctly, you speak of capacity (greater amp/hour ratings) making the packs taller, but what about the higher voltage packs? In looking at your website, it looks like the 9.9 volt pack is taller then a 6.6 volt pack, correct? So even a 9.9 volt pack would still fit in the same footprint area of a 7.2 volt NiMh pack?
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You have a rodent infestation. Shall I terminate?
Understood, and thanks! You guys still have great customer service, I see.
So it looks like I would need a new battery charger, as my Team Checkpoint TC-1030 doesn't have an A123 cell program. At least I don't think it does.
On question 3, if I understand correctly, you speak of capacity (greater amp/hour ratings) making the packs taller, but what about the higher voltage packs? In looking at your website, it looks like the 9.9 volt pack is taller then a 6.6 volt pack, correct? So even a 9.9 volt pack would still fit in the same footprint area of a 7.2 volt NiMh pack?
Yes in both cases whether higher capacity or voltage the packs get taller.The foot print remains the same length and width but the packs get taller. The dimensions are listed on the site.
; my car will suddenly go from full speed to a crawl 
. But I have done this many times and then recharged(approx 20 mins) and go; no ill effects. I have been charging them with my CE charger on the lipo mode with no problems, so a special charger is not required. While I dont know if this wiil ever be the cell of choice I will say that I'm very impressed with the performance and cell life. Just thought I'd interject my thoughts from the standpoint of an actuall user. Here is a pic of them in my 1/12; and of special interest to 1/12 users these fit T-bar cars 
.
