Charging batteries, Peak or Temp shut off?
04-28-2007, 10:05 PM
#1
Charging batteries, Peak or Temp shut off?
Nubi question, I understand using the "peak" option to turn off the charger well enough. How do I increase the battery temp. to match suggested temp. ratings without increasing to a higher that suggested Amp setting or causing a faulse / premature charging "peak"?
using an ICE charger- w/ Temp sensor
charging @ 6A, IB4200 w/5mv per cell-
linear charge-
But... At peak battery temp is around 120deg. not the 135 to 140deg. suggested by the literature supplied with the batteries (inside the box).
I'm I looking at this wrong ...?
using an ICE charger- w/ Temp sensor
charging @ 6A, IB4200 w/5mv per cell-
linear charge-
But... At peak battery temp is around 120deg. not the 135 to 140deg. suggested by the literature supplied with the batteries (inside the box).
I'm I looking at this wrong ...?
Last edited by Speed-Bump; 04-29-2007 at 09:25 AM.
04-29-2007, 06:41 AM
#3
I have the Ice to and only used the temp sensor to prevent over heating.
I used a peak 3/mv.
You can tell if your getting the most from your charge from the mah charged back into them.
And I charged mine at 5 amps they will charge better longer cooler and last longer, hydrides are sensitive to heat.
The high charge rate and to much heat will cause venting.
Are you sure the suggestions were not to exceed these temps.
Try a good discharge. And next charge 5 amps with a 3/mv.
Then 4/m and last 5/mv.
At the 5 amp charge the pack will hold its peak longer through out the race.
OH and like Bermbuster said cold batteries don't charge well for some reason?
So make sure they are at room temp at least before charging.
I used a peak 3/mv.
You can tell if your getting the most from your charge from the mah charged back into them.
And I charged mine at 5 amps they will charge better longer cooler and last longer, hydrides are sensitive to heat.
The high charge rate and to much heat will cause venting.
Are you sure the suggestions were not to exceed these temps.
Try a good discharge. And next charge 5 amps with a 3/mv.
Then 4/m and last 5/mv.
At the 5 amp charge the pack will hold its peak longer through out the race.
OH and like Bermbuster said cold batteries don't charge well for some reason?
So make sure they are at room temp at least before charging.
04-29-2007, 10:37 AM
#4
Don't get me wrong. I'm quite happy with the results generally. There is so many charging / discharging variations described from one battery distributor to another.
Bermbuster: The pack temp. is ambient ~ 60deg. before charging starts; I understand a battery will perform better the second time it’s charged in a row on race day (as long as it has had time to cool down) so the idea that a battery will take a charge better if it starts out warmer makes sense.
UN4RACING: Are you sure the suggestions were not to exceed these temps?
Here is a quote from the literature that came w/ the SMC IB4200 matched pack:
Charging: Use a high quality peak detection charger. Use a 6 amp linear charge with the peak detect(voltage threshold) set at .005(5mv) per cell. A 6 cell pack at .03(30mv). If you own a temperature gun we like the packs to peak around 140 degrees Fahrenheit.
I should add that after I’ve run a battery on the car, I discharge the pack using a light bar (14ea. bulbs ~26 amps) down to 5.4 volts. Then use an equalizing tray to balance out the cells at .9 volts per cell.
The information from each of you makes sense and I do appreciate it …but my main question remains still unanswered. How do I synchronize the suggested peak value and suggested peak temperature. Or should I? I mean ..would it be wrong to not use peak value detection and charge the batteries at a specific amp rating until it reaches the suggested temperature? Or as UN4RACING stated only use the temp. sensor to prevent the packs from overheating?
Thank you.
Bermbuster: The pack temp. is ambient ~ 60deg. before charging starts; I understand a battery will perform better the second time it’s charged in a row on race day (as long as it has had time to cool down) so the idea that a battery will take a charge better if it starts out warmer makes sense.
UN4RACING: Are you sure the suggestions were not to exceed these temps?
Here is a quote from the literature that came w/ the SMC IB4200 matched pack:
Charging: Use a high quality peak detection charger. Use a 6 amp linear charge with the peak detect(voltage threshold) set at .005(5mv) per cell. A 6 cell pack at .03(30mv). If you own a temperature gun we like the packs to peak around 140 degrees Fahrenheit.
I should add that after I’ve run a battery on the car, I discharge the pack using a light bar (14ea. bulbs ~26 amps) down to 5.4 volts. Then use an equalizing tray to balance out the cells at .9 volts per cell.
The information from each of you makes sense and I do appreciate it …but my main question remains still unanswered. How do I synchronize the suggested peak value and suggested peak temperature. Or should I? I mean ..would it be wrong to not use peak value detection and charge the batteries at a specific amp rating until it reaches the suggested temperature? Or as UN4RACING stated only use the temp. sensor to prevent the packs from overheating?
Thank you.
04-29-2007, 04:43 PM
#5
Well they way I understand it is if your peaking (charging) 140 degrees is the highest they like there packs to get at a full charge temp. It does kinda sound like charge till 140 but I wouldn't.
If your packs are fully charged at 120 or 130 degrees thats good.
Repeaking will heat them up to 140 possibly. Now you could raise the peak detection. That would warm them up.
Your discharge method sounds Identical to mine.
So if your packs have charged to 4000 MAH and the temp is 140 then shut it off. And keep in mind that does not mean they are not fully charged. Yet every manufacturer is different, thats how they can say theres are better.
The trick is to get a full charge with as little heat as possible through out the charge. Until the end of the peak of coarse.
I have over the years had best results with the 5 amp charge and the peak mv no higher than 3 or 4.(linear).
When I came from dirt to on road they were charging at 6 amps with 3300's.
In dirt we were charging no more than 4.5 to 5 amps and the batteries lasted a lot longer and performed better over the duration of the round.
By the way there are some serious battery wizards in the electric on road threads they would love to sharpen there wits on this question.
Give it a try. Or do a 4200 battery search. You may find the exact answer your wanting? But try the 5 amp 3mv first see if you like it.
Thats the long version.
In short if they truly meant 140 degrees and pack is done, then why not say don't worry about the peak detection and just charge to 140 degrees and be done.
If your packs are fully charged at 120 or 130 degrees thats good.
Repeaking will heat them up to 140 possibly. Now you could raise the peak detection. That would warm them up.
Your discharge method sounds Identical to mine.
So if your packs have charged to 4000 MAH and the temp is 140 then shut it off. And keep in mind that does not mean they are not fully charged. Yet every manufacturer is different, thats how they can say theres are better.
The trick is to get a full charge with as little heat as possible through out the charge. Until the end of the peak of coarse.
I have over the years had best results with the 5 amp charge and the peak mv no higher than 3 or 4.(linear).
When I came from dirt to on road they were charging at 6 amps with 3300's.
In dirt we were charging no more than 4.5 to 5 amps and the batteries lasted a lot longer and performed better over the duration of the round.
By the way there are some serious battery wizards in the electric on road threads they would love to sharpen there wits on this question.
Give it a try. Or do a 4200 battery search. You may find the exact answer your wanting? But try the 5 amp 3mv first see if you like it.
Thats the long version.
In short if they truly meant 140 degrees and pack is done, then why not say don't worry about the peak detection and just charge to 140 degrees and be done.
04-29-2007, 05:25 PM
#6
http://www.promatchracing.com/ibins.php
http://www.slingshotbatteries.com/ra...g-storage.html
http://www.gpbatteries.com/pdf/GP430schR_DS.pdf
The GP link is the closest I could find to the 4200 in specks.
http://www.slingshotbatteries.com/ra...g-storage.html
http://www.gpbatteries.com/pdf/GP430schR_DS.pdf
The GP link is the closest I could find to the 4200 in specks.
Last edited by UN4RACING; 04-29-2007 at 06:02 PM.
04-30-2007, 03:23 PM
#7
Speed-Bump,
I also have an ICE charger and IB4200 cells. If you're really looking to get your cells to hit 140F, turn up your charge amperage, 7.2 to 8 amps should do it. BUT, if you go with that high of a charge rate, I'd turn down the Peak Sensitivity (Peak sens.) to either ZEROpk or 3mV to make sure that the charger stops EXACTLY when the cells have peaked.
We (myself and the people I know in R/C) refer to this as "slam charging". ...and we only do this for on-road (sprint, oval, Touring Car) racing. It's pointless for off-road where the punch of an 8-amp charge is lost to the slipper clutch and poor traction on loose surfaces.
There are a few of caveats to slam charging:
1) You need to have good power supply that can crank out a consistent, stable amperage to charge at a higher charge rate. I've heard numbers in the 30~50% higher amperage than the rate at which you're actually charging. ie: 8-amp charge rate requires a 12-amp power supply.
2) The ICE charger max cut-off temp is 132F. So you'll have to temp it by hand with a temp gun.
3) The internal temperature of the cell is typically 20% higher than the skin. Also, a cell's internal temperature will continue to rise for several minutes after charging ends, so keep this in mind.
4) If you overheat your cells and they vent, you'll decrease their usefull life substantially.
5) If you really over heat your cells, and they vent, and the plates melt, the cells will most likely short-circuit ruining your charger, and may also explode.
I don't really get how someone could accurately charge based on temperature. There are so many other variables involved. Ambient temperature, initial cell temp, charge rate, charge type (step, linear, 4-step, 5-step, CC/CV, peak, timed, etc.), charger type and brand, input voltage and amperage... these are all factors that impact how a cell is charged. Far too many factors for a manufacturer to make a blanket statement like "charge to 140F".
Ultimately, from everything I know and have read about NiMH cells... you'll get the most out of them using proper peak-detect charging and cutoff-voltage discharging procedures (which you are doing quite well).
Or, you could always call the manufacturer and and ask for clarification.
Hope this helps.
Mr.Maim
I also have an ICE charger and IB4200 cells. If you're really looking to get your cells to hit 140F, turn up your charge amperage, 7.2 to 8 amps should do it. BUT, if you go with that high of a charge rate, I'd turn down the Peak Sensitivity (Peak sens.) to either ZEROpk or 3mV to make sure that the charger stops EXACTLY when the cells have peaked.
We (myself and the people I know in R/C) refer to this as "slam charging". ...and we only do this for on-road (sprint, oval, Touring Car) racing. It's pointless for off-road where the punch of an 8-amp charge is lost to the slipper clutch and poor traction on loose surfaces.
There are a few of caveats to slam charging:
1) You need to have good power supply that can crank out a consistent, stable amperage to charge at a higher charge rate. I've heard numbers in the 30~50% higher amperage than the rate at which you're actually charging. ie: 8-amp charge rate requires a 12-amp power supply.
2) The ICE charger max cut-off temp is 132F. So you'll have to temp it by hand with a temp gun.
3) The internal temperature of the cell is typically 20% higher than the skin. Also, a cell's internal temperature will continue to rise for several minutes after charging ends, so keep this in mind.
4) If you overheat your cells and they vent, you'll decrease their usefull life substantially.
5) If you really over heat your cells, and they vent, and the plates melt, the cells will most likely short-circuit ruining your charger, and may also explode.
I don't really get how someone could accurately charge based on temperature. There are so many other variables involved. Ambient temperature, initial cell temp, charge rate, charge type (step, linear, 4-step, 5-step, CC/CV, peak, timed, etc.), charger type and brand, input voltage and amperage... these are all factors that impact how a cell is charged. Far too many factors for a manufacturer to make a blanket statement like "charge to 140F".
Ultimately, from everything I know and have read about NiMH cells... you'll get the most out of them using proper peak-detect charging and cutoff-voltage discharging procedures (which you are doing quite well).
Or, you could always call the manufacturer and and ask for clarification.
Hope this helps.
Mr.Maim
04-30-2007, 05:48 PM
#8
Mr.Maim,
I’ve not heard of “slam charging” before. I can understand why a person would not want to risk destroying their batteries just to try to reach some unnecessary temperature goal. A side note… I run on dirt (clay-indoors ya know) and am piloting a Losi XX-Tcr (old school). No carpet for me.
As a fellow ICE charger user, how do you feel about “step-charging”? Have you had any positive or negative results? Personally I can’t really say It’s made much difference.
UN4RACING,
Thanks for some great suggestions and links for me to check out. I’ll try the 5 amp 3mv to see if I notice much difference from what I’ve been doing. If charging at 5 amps (for longer battery life) compared to 6 amps (listed on battery label) is not to noticeable while on the track… why not do it?
Thank You.
I’ve not heard of “slam charging” before. I can understand why a person would not want to risk destroying their batteries just to try to reach some unnecessary temperature goal. A side note… I run on dirt (clay-indoors ya know) and am piloting a Losi XX-Tcr (old school). No carpet for me.
As a fellow ICE charger user, how do you feel about “step-charging”? Have you had any positive or negative results? Personally I can’t really say It’s made much difference.
UN4RACING,
Thanks for some great suggestions and links for me to check out. I’ll try the 5 amp 3mv to see if I notice much difference from what I’ve been doing. If charging at 5 amps (for longer battery life) compared to 6 amps (listed on battery label) is not to noticeable while on the track… why not do it?
Thank You.
05-01-2007, 12:59 AM
#9
The book for my IB4200's say to charge at 6amp's and peak them at about 120 to 130 degrees. Mine are only getting to about 90 or 100, and my chager is set on DP of 35 or 40mv per pack and I do not discharg them after every race I just repeak them and be done after the day is up I discharge to 0.9v per cell.
05-02-2007, 01:52 PM
#10
Speed-Bump,
The only people I know that charge like that (7~8 amps and higher) are people who can afford to vent their cells and replace them frequently.
Personally, I charge my brand new EP4200s at 6 amps; my IB4200s that I'm replacing I charged at 6 amps; my GP3300s that I had earlier at 6 amps... It just seems to be a good balance between charge rate (speed), and deliverable punch back from the pack when running. You'll really notice the difference between 6 amps and 5 amps. Charged at 6 amps, in the first minute-and-a-half of running a freshly charged pack you'll have great "punch", whereas when charged at 5 amps you'll have less "punch". It's noticable to me... I'm sure others would agree.
As for the Step Charging: I have not tried it yet, and I've had my ICE for 3 months now. Your post, and this thread, caused me to re-read the manual for the charger over the last two days... and I have to say: I'm intrigued. We both know that the point of charging is to get as much energy into the cells without overheating them, so in theory, the step charging process looks like a winner... I just have not had the opportunity to mess with it just yet.
Mr.Maim
The only people I know that charge like that (7~8 amps and higher) are people who can afford to vent their cells and replace them frequently.
Personally, I charge my brand new EP4200s at 6 amps; my IB4200s that I'm replacing I charged at 6 amps; my GP3300s that I had earlier at 6 amps... It just seems to be a good balance between charge rate (speed), and deliverable punch back from the pack when running. You'll really notice the difference between 6 amps and 5 amps. Charged at 6 amps, in the first minute-and-a-half of running a freshly charged pack you'll have great "punch", whereas when charged at 5 amps you'll have less "punch". It's noticable to me... I'm sure others would agree.
As for the Step Charging: I have not tried it yet, and I've had my ICE for 3 months now. Your post, and this thread, caused me to re-read the manual for the charger over the last two days... and I have to say: I'm intrigued. We both know that the point of charging is to get as much energy into the cells without overheating them, so in theory, the step charging process looks like a winner... I just have not had the opportunity to mess with it just yet.
Mr.Maim
05-02-2007, 01:57 PM
#11
Originally Posted by shawn17
The book for my IB4200's say to charge at 6amp's and peak them at about 120 to 130 degrees. Mine are only getting to about 90 or 100, and my chager is set on DP of 35 or 40mv per pack and I do not discharg them after every race I just repeak them and be done after the day is up I discharge to 0.9v per cell.
When you say "my chager is set on DP of 35 or 40mv per pack", do you mean 3.5mv or 4.0mv, or 35 or 40 as you stated? If you're setting it that high, you're not getting anywhere near a full charge. If they're good cells, you should be setting your Delta Peak detection to no higher than 5mv, and best at 3mv or ZeroPeak. That way your charger will detect the point when the cells no longer are accepting voltage and stop the charge. If you set it really high, your charge will end long before your cells have peaked.
Was that a typo or are you setting it that high?
Mr.Maim
05-08-2007, 11:31 PM
#12
Just a follow-up post if anybody cares:
The EP4200 cells I recently bought are the best and most mysterious cells I have ever seen. From a discharge to 0.9 volts I have been charging them at 7-amps and they barely break 100-degrees fahrenheit! Also, they're taking over 4500+mAh of energy!
I've never seen anything like these before! They're awesome and MAN do they have punch!
The EP4200 cells I recently bought are the best and most mysterious cells I have ever seen. From a discharge to 0.9 volts I have been charging them at 7-amps and they barely break 100-degrees fahrenheit! Also, they're taking over 4500+mAh of energy!
I've never seen anything like these before! They're awesome and MAN do they have punch!
05-09-2007, 12:00 AM
#13
Originally Posted by Mr.Maim
Just a follow-up post if anybody cares:
The EP4200 cells I recently bought are the best and most mysterious cells I have ever seen. From a discharge to 0.9 volts I have been charging them at 7-amps and they barely break 100-degrees fahrenheit! Also, they're taking over 4500+mAh of energy!
I've never seen anything like these before! They're awesome and MAN do they have punch!
The EP4200 cells I recently bought are the best and most mysterious cells I have ever seen. From a discharge to 0.9 volts I have been charging them at 7-amps and they barely break 100-degrees fahrenheit! Also, they're taking over 4500+mAh of energy!
I've never seen anything like these before! They're awesome and MAN do they have punch!
05-09-2007, 12:34 AM
#14
They're EP cells (East Power) and are a pretty recent enterant into the US market. Not sure about the other side of the pond.
If you do some searches in these forums you'll find info about them. I'm too tired to post any links... sorry.
I got mine from Ken and Dawn Collins, oners of KC Racing
www.kc-racing.com
KMR Batteries carries the exact same cells
www.kmrbatteries.com
I am EXTREMELY PLEASED with these cells! Check out the labels! Runtime of 455+!!!
If you do some searches in these forums you'll find info about them. I'm too tired to post any links... sorry.
I got mine from Ken and Dawn Collins, oners of KC Racing
www.kc-racing.com
KMR Batteries carries the exact same cells
www.kmrbatteries.com
I am EXTREMELY PLEASED with these cells! Check out the labels! Runtime of 455+!!!
05-09-2007, 06:42 AM
#15
Thanks mang, im hoping these are more robust than the IB's
