Nov 30, 2011, 06:18 PM
Registered User
United Kingdom, London
Joined Dec 2003
3,278 Posts
Quote:
 Originally Posted by teeforb i was asking about C/?, which is an option in the PL chargers. but it seems u understand the concept. therefore, im not sure what you are confused about...
Yes I do understand the concept of C thanks, but not owning one of these yet but in the very near future I will, I do own already 2 of the very 1st cell pro chargers(excellent).. So I'm loosely following this thread... I wasn't sure if it was balance current or charge current you were asking about that's where my concussion was!
Nov 30, 2011, 06:29 PM
Registered User
United Kingdom, London
Joined Dec 2003
3,278 Posts
Quote:
 Originally Posted by teeforb but the lipo itself (resting voltage) will not be 4.2v.
Correct when a charger charges the battery it cuts off at 4.2v the battery will rest at something like 4.19/4.18 (a few factors will apply here, internally resistance being the main one) so therefore to rest at 4.2v the battery would have to be charged to 4.21-4.22 which is a no go for lipo's!
 Nov 30, 2011, 07:09 PM Southern Pride Haralson County GA. USA Joined Oct 2004 34,852 Posts The cell's resting voltage will be 4.2 if the cells are good ones and the neding charge rate is low enough and last long enough. That is why the C/10 / C/10 and C/3 were mentioned. That being at what fraction of the set charge rate the CV stage ends. If charge rate is say 10A then a C/10 CV stage will end the charge when the cells are at 4.2 and the charge rate is 1A or 10A / 10. If set to C/20 then the charge will not end until cells are holding at 4.2 and charge rate drops to 0.5A or 10/20. These are all charging setting variables which have been covered numerious times over the years. FYI to many worry to much about finished cell voltage being right at 4.2V. Anything at or above 4.15 per cell is fine for all but those in serious competition. The FMA chargers have a Long Life setting which charges to only 4.1V per cell and this is a setting which should be used more often by most if they would like thier LiPolys to last longer. Charles
Nov 30, 2011, 07:32 PM
Registered User
Seattle
Joined Sep 2007
2,370 Posts
Quote:
 Originally Posted by topgearuk This is not making much sense to me, so you mainly charge at C/10 which is effectively a slow/ trickle charge?
I was referring to the CV (constant voltage) cuttoff setting as Everydayflier was describing. The way teeforb formed the question, I suspect that was what he was asking vs, charge rate.

BTW, the ability to set the CV cuttoff is something that not all chargers offer. The PL8 (and PL6) have many options to tune the charge. After a friend of mine reported that his non-FMA charger was charging extreemly fast but balancing accuracy was not perfect, I set out to see how fast I could charge a pack without increasing the charge current. The present settings that were tuned were C/# as well as the balance deadband, and balance set point.

As you can see, I did pretty well. That's the nice thing about this charger. You can make it charge anyway you want. Slow and accurrate, fast and accurate... have it your way. Most user will do very well using the built in presets. But if you get curious, the options in the CCS provide many layers to explore. Not required, but certainly nice to have.

Voltz 3300 6s
==============================
Starting from storage charge 3.84v

C/20
Time 16:55
Mah 1497
V 4.195,200,201, 201,201,196
Delta .006mv
Balance set point -1mv

C/10
Time 13:48
Mah 1462
V 4.192, 196, 192,196,192,192
Delta .004mv
Balance set point -2mv

C/3
Time 11:51
Mah 1466
V 4.182, 187,184,188,187,182
Delta .006mv
Balance set point -1mv
Nov 30, 2011, 07:53 PM
Registered User
Joined Nov 2011
117 Posts
im wondering if setting max voltage per cell to like 4.15v, if that would reduce some of the CV charge time? And supposedly, increases the life of your cells.

Quote:
 Originally Posted by Gregor99 I was referring to the CV (constant voltage) cuttoff setting as Everydayflier was describing. The way teeforb formed the question, I suspect that was what he was asking vs, charge rate. BTW, the ability to set the CV cuttoff is something that not all chargers offer. The PL8 (and PL6) have many options to tune the charge. After a friend of mine reported that his non-FMA charger was charging extreemly fast but balancing accuracy was not perfect, I set out to see how fast I could charge a pack without increasing the charge current. The present settings that were tuned were C/# as well as the balance deadband, and balance set point. As you can see, I did pretty well. That's the nice thing about this charger. You can make it charge anyway you want. Slow and accurrate, fast and accurate... have it your way. Most user will do very well using the built in presets. But if you get curious, the options in the CCS provide many layers to explore. Not required, but certainly nice to have. Voltz 3300 6s ============================== Starting from storage charge 3.84v C/20 Time 16:55 Mah 1497 V 4.195,200,201, 201,201,196 Delta .006mv Balance deadband 2mv Balance set point -1mv C/10 Time 13:48 Mah 1462 V 4.192, 196, 192,196,192,192 Delta .004mv Balance deadband 5mv Balance set point -2mv C/3 Time 11:51 Mah 1466 V 4.182, 187,184,188,187,182 Delta .006mv Balance deadband 2mv Balance set point -1mv
 Nov 30, 2011, 08:08 PM Registered User Tallahassee, FL Joined Sep 2009 1,735 Posts Do the Powerlab chargers have a fast charge mode which ends the charge when the first cell reaches 4.2 volts and eliminates the balancing altogether? I ask because most of the 50 watt chargers have this and it really saves a lot of time if your packs are well balanced.
Nov 30, 2011, 09:01 PM
Registered User
Seattle
Joined Sep 2007
2,370 Posts
Quote:
 Originally Posted by Turner2 I ask because most of the 50 watt chargers have this and it really saves a lot of time if your packs are well balanced.
Those cheap chargers that have no balancing and stop the charge when a single cell gets to 4.2v are bad for batteries. I had a friend that was using one and was complaining the battery seemed to be down on power and dying prematurely. We finaly got around to checking his cell voltages. One cell was 4.2 the others were below 4v. He ordered a Cellpro 4s (this was a while ago) and the Cellpro was able to recover the battery. It balanced and ran well after that.

Another friend was using one and I checked the pack to see how well it had one. 4.2 on one cell, the other two were 4.15v. He didn't have that many cycles on it, but you could see it going down hill.

If you want super fast charges, look at my C/3 setting above. Balanced as we as fast. Not 100% charged but darn close.
Nov 30, 2011, 09:05 PM
Registered User
Seattle
Joined Sep 2007
2,370 Posts
Quote:
 Originally Posted by teeforb im wondering if setting max voltage per cell to like 4.15v, if that would reduce some of the CV charge time? And supposedly, increases the life of your cells.
CV charge time won't be that much faster. But CC charge will be a little faster since you are putting less into the pack. 4.15v per cell is better for battery life, this is true.
 Nov 30, 2011, 11:39 PM Registered User Joined Nov 2011 117 Posts 1) Im discharging two 2s in series. The max current it will discharge is 2.9A. Any reason why? 2) looking at preset "storage", where in the settings does it say this profile is for storage? I charged two 2s 5600 from 41% to 4.17v per cell in 7minutes. Normally, it'll take 35mins.
Nov 30, 2011, 11:56 PM
Registered User
Tallahassee, FL
Joined Sep 2009
1,735 Posts
Quote:
 Originally Posted by Gregor99 Those cheap chargers that have no balancing and stop the charge when a single cell gets to 4.2v are bad for batteries...
I'm not talking about chargers that cannot balance and I'm not talking about charging without balance leads connected. I'm talking about balancing chargers that also have a LiPo fast charge mode that ends the charge at the point that balancing would normally start. Virtually all of the 50 watt 4 button balancing chargers have this fast charge mode that skips the balance phase.

But the question is do the Powerlab chargers have a fast charge mode that skips the balance phase?

I always get a lot of heat for this but if the cells are within a couple hundredths of a volt when one cell reaches 4.2 volts then there is no need to balance. I never charge with anything but a balancing charger. I never charge without the balance lead connected and I always monitor all cell voltages. I have a number of packs that I run through several cycles without balancing and the cells stay within a few hundredths of a volt.
Dec 01, 2011, 12:01 AM
Registered User
Joined Nov 2011
117 Posts
It has a fast charge profile for lipo. I haven't used it yet.

Quote:
 Originally Posted by Turner2 I'm not talking about chargers that cannot balance and I'm not talking about charging without balance leads connected. I'm talking about balancing chargers that also have a LiPo fast charge mode that ends the charge at the point that balancing would normally start. Virtually all of the 50 watt 4 button balancing chargers have this fast charge mode that skips the balance phase. But the question is do the Powerlab chargers have a fast charge mode that skips the balance phase? I always get a lot of heat for this but if the cells are within a couple hundredths of a volt when one cell reaches 4.2 volts then there is no need to balance. I never charge with anything but a balancing charger. I never charge without the balance lead connected and I always monitor all cell voltages. I have a number of packs that I run through several cycles without balancing and the cells stay within a few hundredths of a volt.
Dec 01, 2011, 12:02 AM
Registered User
Seattle
Joined Sep 2007
2,370 Posts
Quote:
 Originally Posted by teeforb 1) Im discharging two 2s in series. The max current it will discharge is 2.9A. Any reason why?
Internal charging is limited to 50 watts. 4s=16.8v, 16.8/50=2.97.
Dec 01, 2011, 12:10 AM
Registered User
Tallahassee, FL
Joined Sep 2009
1,735 Posts
Quote:
 Originally Posted by teeforb It has a fast charge profile for lipo. I haven't used it yet.
Thanks!
Dec 01, 2011, 12:11 AM
Registered User
Seattle
Joined Sep 2007
2,370 Posts
Quote:
 Originally Posted by Turner2 if the cells are within a couple hundredths of a volt when one cell reaches 4.2 volts then there is no need to balance.
If the cells are that close already then it won't take long for any charger to balance. Its also worth pointing out that many confuse "balancing" with the CV stage of charging. This is the stage were the cells have reached 4.2v and the charger slowly reduces the current at the same time the cell voltage is sagging. The voltage is kept at 4.2v during this stage as the cells settle. All Cellpro chargers start balancing well before 4.2. By the time the voltage gets to the CV stage, its already balanced. You can really speed up the CV stage by using either using the "Faster Charge" preset, or even further with the CCS and changing the C/? setting.

Also, the PL6 and PL8 have 1 amp balancing power. The charger will not have to slow the charge down to balance.
Dec 01, 2011, 12:36 AM
Registered User
Joined Nov 2011
117 Posts
Quote:
 Originally Posted by Gregor99 Internal charging is limited to 50 watts. 4s=16.8v, 16.8/50=2.97.
Ah, 50w was my missing piece.