Hi there,
I am wondering who else here uses rechargeable batteries at least
enough to know something about them by first hand experience.
Mostly interested in NiMH and Li ion cells, but also lead acid i guess.
I am wondering if you also find the NiMH cells to have lower capacity
then they are marked and if you use a battery tester of any kind.
Anyone else here charge/test batteries quite often?
Anyone else here charge/test batteries quite often?
LEDs vs Bulbs, LEDs are winning.
-
Robert Reed
- Posts: 2277
- Joined: Wed Nov 24, 2004 1:01 am
- Location: ASHTABULA,OHIO
- Contact:
Hello MrAl
I am not real knowledgeable about rechargeables, but since you are asking for experiences, I thought I would throw my 2 cents wort in for the heck of it.
My digital camera uses NI-MH batts. and they seem to go flat in no time at all. Their perfomance now is the same as the day I bought them, and these were supplied with the Manu's battery charger. They are 2000 Mah AA batts. Their charge rate is 15 hrs. @ 180 Ma or 5 hrs @ 500 Ma.
Every time I go to use the camera (maybe idle for 1 month) the batterys are flat and I switch to my backup Alkalines to get a few pictures.
An outfit I used to work at had such poor performance from rechargeables(do not remember what type - only that they were AA's) used in their pagers ( one day max.) that they finally switched over to Alkalines ( one week) and stayed with them.
For me , rechargeables have always been a love-hate relationship. Can't live without them and can't live with them.
Some day I am going to do a cost analysis between them and my beloved Alkalines for a projected period of time just to actually see how much I actually save in rechargeables over Alkalines. This analysis would also include "pain in the A** factor" of rechargeables
I do not use a battery tester to check these, since the battery charger is automated and shuts off at full charge - at least thats what the Manu tells me.
I am not real knowledgeable about rechargeables, but since you are asking for experiences, I thought I would throw my 2 cents wort in for the heck of it.
My digital camera uses NI-MH batts. and they seem to go flat in no time at all. Their perfomance now is the same as the day I bought them, and these were supplied with the Manu's battery charger. They are 2000 Mah AA batts. Their charge rate is 15 hrs. @ 180 Ma or 5 hrs @ 500 Ma.
Every time I go to use the camera (maybe idle for 1 month) the batterys are flat and I switch to my backup Alkalines to get a few pictures.
An outfit I used to work at had such poor performance from rechargeables(do not remember what type - only that they were AA's) used in their pagers ( one day max.) that they finally switched over to Alkalines ( one week) and stayed with them.
For me , rechargeables have always been a love-hate relationship. Can't live without them and can't live with them.
Some day I am going to do a cost analysis between them and my beloved Alkalines for a projected period of time just to actually see how much I actually save in rechargeables over Alkalines. This analysis would also include "pain in the A** factor" of rechargeables
I do not use a battery tester to check these, since the battery charger is automated and shuts off at full charge - at least thats what the Manu tells me.
-
Janitor Tzap
- Posts: 1710
- Joined: Sat Aug 12, 2006 5:17 pm
- Contact:
Actually the Ni-MH going dead or {Flat} after just sitting a month in the camera,Robert Reed wrote:Hello MrAl
I am not real knowledgeable about rechargeables, but since you are asking for experiences, I thought I would throw my 2 cents wort in for the heck of it.
My digital camera uses NI-MH batts. and they seem to go flat in no time at all. Their perfomance now is the same as the day I bought them, and these were supplied with the Manu's battery charger. They are 2000 Mah AA batts. Their charge rate is 15 hrs. @ 180 Ma or 5 hrs @ 500 Ma.
Every time I go to use the camera (maybe idle for 1 month) the batterys are flat and I switch to my backup Alkalines to get a few pictures.
An outfit I used to work at had such poor performance from rechargeables(do not remember what type - only that they were AA's) used in their pagers ( one day max.) that they finally switched over to Alkalines ( one week) and stayed with them.
For me , rechargeables have always been a love-hate relationship. Can't live without them and can't live with them.
Some day I am going to do a cost analysis between them and my beloved Alkalines for a projected period of time just to actually see how much I actually save in rechargeables over Alkalines. This analysis would also include "pain in the A** factor" of rechargeables
I do not use a battery tester to check these, since the battery charger is automated and shuts off at full charge - at least thats what the Manu tells me.
is not uncommon with most digital cameras.
{Mainly because of the circuit design for the "on-off" feature in the camera.}
My mother has a one that eats up batteries like crazy.
Doesn't matter if its Alkalines, or Rechargeables.
{But the Alkalines do last abit longer than Carbon, or the Rechargeable Batteries.}
Have you considered Rechargeable Alkalines?
I have a friend who uses the Rechargeable Alkalines.
He can only get about 20 Recharges out of them before they will no longer take a charge.
There was an Alkaline Battery Recharger that "Buddy-L" made that kind of flopped.
It could only get maybe 10 Recharges out of an Alkaline Battery before it died.
With Rechargeable Alkalines, your not to let the batteries go completely dead.
When you notice that the battery life is almost gone.
You then put them on the recharger.
Otherwise it may not take a charge.
Most Nicad and Ni-MH are rated for a maximum 500 recharges.
Thus, this makes them more cost effective in the long run.
Like any good camera man knows.....
You just make sure to keep all your batteries fully charged, before you go out on a shoot.
And carry extra charged batteries just in case.
Signed: Janitor Tzap
Mr Al,
I have been doing testing, and building chargers for NiCad NiMH and Lead-Acid batteries for quite a number of years. I wrote a series of articles once for an amateur radio news letter about 8 years ago. I have copies of the complete newsletter in PDF format that I would be glad to share with any one that would like them.
The Nicad and the NiMH rechargeable have a fast self discharge rate and as a result the shelf life at room temperature 68 degrees F is not much more than 10 days. I have made numerous chargers for both using the charging current limited to the capacity of the cell x .095. By using this small amount you can leave the charger for extended periods and the cells will never overcharge.
Lead-Acid have a shelf life of about 6 months after fully charged. This time varies between manufacturers and the temperature at which they are stored. I have found to float them between 2.25 and 2.3 V per cell they will also never over charge. The only ones you have to limit the charge current with these voltages is the ones that are 4 AH (amp/hours) and less.
The discarge rates for the Ni-Cad and the NiMh can be the capacity.
If the batteries are 800mA, you can generally discharge them for 800mA for an hour.
The lead-acid batteries have a 20 hour discharge rate. So if the battery is 10AH that means the discharge rate for maximum energy is 500mA/hr.
If you discharge it at 10 amps it will last about 1/2 hour. Short term you can get many times the AH rate out of the battery.
For testing I built a load bank that has a NPN power transistor mounted ona big heatsink. The collector is connected to the + of the battery.
The emitter of the transistor has a low value of resistor to ground. The ground is connected to the - of the battery. The base is fed with an op-amp. One imput of the op-amp is the voltage from the emitter resistor.
The other op-amp input is from a variable regulated voltage.
This adjustable voltage determins the discharge current of the load bank.
Ned
I have been doing testing, and building chargers for NiCad NiMH and Lead-Acid batteries for quite a number of years. I wrote a series of articles once for an amateur radio news letter about 8 years ago. I have copies of the complete newsletter in PDF format that I would be glad to share with any one that would like them.
The Nicad and the NiMH rechargeable have a fast self discharge rate and as a result the shelf life at room temperature 68 degrees F is not much more than 10 days. I have made numerous chargers for both using the charging current limited to the capacity of the cell x .095. By using this small amount you can leave the charger for extended periods and the cells will never overcharge.
Lead-Acid have a shelf life of about 6 months after fully charged. This time varies between manufacturers and the temperature at which they are stored. I have found to float them between 2.25 and 2.3 V per cell they will also never over charge. The only ones you have to limit the charge current with these voltages is the ones that are 4 AH (amp/hours) and less.
The discarge rates for the Ni-Cad and the NiMh can be the capacity.
If the batteries are 800mA, you can generally discharge them for 800mA for an hour.
The lead-acid batteries have a 20 hour discharge rate. So if the battery is 10AH that means the discharge rate for maximum energy is 500mA/hr.
If you discharge it at 10 amps it will last about 1/2 hour. Short term you can get many times the AH rate out of the battery.
For testing I built a load bank that has a NPN power transistor mounted ona big heatsink. The collector is connected to the + of the battery.
The emitter of the transistor has a low value of resistor to ground. The ground is connected to the - of the battery. The base is fed with an op-amp. One imput of the op-amp is the voltage from the emitter resistor.
The other op-amp input is from a variable regulated voltage.
This adjustable voltage determins the discharge current of the load bank.
Ned
-
Robert Reed
- Posts: 2277
- Joined: Wed Nov 24, 2004 1:01 am
- Location: ASHTABULA,OHIO
- Contact:
Jan Zap
"Actually the Ni-MH going dead or {Flat} after just sitting a month in the camera,
is not uncommon with most digital cameras.
{Mainly because of the circuit design for the "on-off" feature in the camera.} "
Boy, you can say that again! This initially happened with just regular Alkaline batterys in the camera. A little detective work revealed that the camera was still drawing 0.9 ma even with the camera turned off (memory refesh current?), and of course the manu never tells you these things! This would amount to about 750 ma/mo. drain. When freshly charged batterys were reinstalled, I released the batt. compartment latch. This placed the contacts in the "just ajar" position and opened up the circuit, but even in their idle state they went flat in less than 2 weeks, confirming K7's posting. I now carry a spare set of good Alkalines along with fresh charged batterys in the camera, just in case.
K7elp60
"Lead-Acid have a shelf life of about 6 months after fully charged. This time varies between manufacturers and the temperature at which they are stored. I have found to float them between 2.25 and 2.3 V per cell they will also never over charge. The only ones you have to limit the charge current with these voltages is the ones that are 4 AH (amp/hours) and less."
I have always floated my lead acids at 13.2 volts as you have described and even indefinately to the batts. end of life (6-7 years) and no problems. One thing I would like to compare notes with you on - years ago I read some literature from one of the major manufacturers of lead acid batterys
on self discharge rates of automotive batterys (50 amp hour size) and it was determined that these style batterys have a self discharge rate of one milliamp per amp hour of capacity. So using that info, I have always designed my chargers to trickle charge at 50 milliamps after initial charging is shut down. Of course technology changes by the month anymore and this may be outdated for todays batterys. Do you have any new or additional notes on that subject?
"Actually the Ni-MH going dead or {Flat} after just sitting a month in the camera,
is not uncommon with most digital cameras.
{Mainly because of the circuit design for the "on-off" feature in the camera.} "
Boy, you can say that again! This initially happened with just regular Alkaline batterys in the camera. A little detective work revealed that the camera was still drawing 0.9 ma even with the camera turned off (memory refesh current?), and of course the manu never tells you these things! This would amount to about 750 ma/mo. drain. When freshly charged batterys were reinstalled, I released the batt. compartment latch. This placed the contacts in the "just ajar" position and opened up the circuit, but even in their idle state they went flat in less than 2 weeks, confirming K7's posting. I now carry a spare set of good Alkalines along with fresh charged batterys in the camera, just in case.
K7elp60
"Lead-Acid have a shelf life of about 6 months after fully charged. This time varies between manufacturers and the temperature at which they are stored. I have found to float them between 2.25 and 2.3 V per cell they will also never over charge. The only ones you have to limit the charge current with these voltages is the ones that are 4 AH (amp/hours) and less."
I have always floated my lead acids at 13.2 volts as you have described and even indefinately to the batts. end of life (6-7 years) and no problems. One thing I would like to compare notes with you on - years ago I read some literature from one of the major manufacturers of lead acid batterys
on self discharge rates of automotive batterys (50 amp hour size) and it was determined that these style batterys have a self discharge rate of one milliamp per amp hour of capacity. So using that info, I have always designed my chargers to trickle charge at 50 milliamps after initial charging is shut down. Of course technology changes by the month anymore and this may be outdated for todays batterys. Do you have any new or additional notes on that subject?
-
Smoke_Maker
- Posts: 76
- Joined: Fri Aug 04, 2006 6:02 pm
- Location: Las Vegas, Nevada
- Contact:
I know almost nothing about NiMH and Li ion cells, but I have committed my share of lead acid batticide from over charging, over discharging and poisoning. I learned a lot along the way, lead acid batteries are living monsters, they need attention, feeding, watering and exercise to keep them happy. Each lead acid battery has it’s own personality.
If you want to series/parallel Li ion cells you should use a BMS
If you want to series/parallel Li ion cells you should use a BMS
Richard Furniss
is it suppose to smoke like that ?
is it suppose to smoke like that ?
THis link is the next best to an encyclopedia on the subject.
http://www.batteryuniversity.com/parttwo-33.htm
http://www.batteryuniversity.com/parttwo-33.htm
Hi again,
Thanks for all the interesting replies.
I am looking into a chip that can test up to 4 cells at once
and has a computer interface to give you all the info on how
the cell actually makes out in real life. The cost of
the chip is just under 5 dollars and requires a min amount
of support parts, like some 1/4 watt resistors and a 78L05
regulator. I was sort of wondering if anyone else would
be interested in this chip too. Can do just about any
kind of battery, not limited to NiMH.
Here's a screen shot:
BTW, to everyone:
Perhaps you guys should try the low self discharge type NiMH
cells. They come in several varieties now...Sanyo makes
Eneloops, Rayovac makes their 'Hybrid', and Kodak makes
their "Pre-Charged" cells. All of these types are a
special kind of NiMH cell that lasts a year and still
has some kick left, unlike conventional NiMH's.
They can be recharged same as NiMH's in the same chargers
and cycle life is about the same.
Robert:
I have the same problem with some cells whether they are in a camera
or not. The Energizer 2500mAh cells are known to be defective,
and i have tested them several times to verify that the capacity
is really only 1700mAh anyway, and they have really bad self discharge.
But in the camera any cell will run down as you know, and i tested
my camera too and found it draws about 500ua if i rem right when it's
not even being used. Thus, i take the cells out when im done
with it even if for only a week.
Janitor:
I've tried the rechargeable alkies and dont really like them.
They dont recharge enough times. They are still better than
using regular alkalines however as i think you noted.
I used to use them a long while back when nothing else would
come close. Now that NiMH is around i dont need them.
k7elp60:
I wouldnt mind taking a look at your masterpiece if you provide a link
or email me a copy.
Thanks for all the interesting replies.
I am looking into a chip that can test up to 4 cells at once
and has a computer interface to give you all the info on how
the cell actually makes out in real life. The cost of
the chip is just under 5 dollars and requires a min amount
of support parts, like some 1/4 watt resistors and a 78L05
regulator. I was sort of wondering if anyone else would
be interested in this chip too. Can do just about any
kind of battery, not limited to NiMH.
Here's a screen shot:
BTW, to everyone:
Perhaps you guys should try the low self discharge type NiMH
cells. They come in several varieties now...Sanyo makes
Eneloops, Rayovac makes their 'Hybrid', and Kodak makes
their "Pre-Charged" cells. All of these types are a
special kind of NiMH cell that lasts a year and still
has some kick left, unlike conventional NiMH's.
They can be recharged same as NiMH's in the same chargers
and cycle life is about the same.
Robert:
I have the same problem with some cells whether they are in a camera
or not. The Energizer 2500mAh cells are known to be defective,
and i have tested them several times to verify that the capacity
is really only 1700mAh anyway, and they have really bad self discharge.
But in the camera any cell will run down as you know, and i tested
my camera too and found it draws about 500ua if i rem right when it's
not even being used. Thus, i take the cells out when im done
with it even if for only a week.
Janitor:
I've tried the rechargeable alkies and dont really like them.
They dont recharge enough times. They are still better than
using regular alkalines however as i think you noted.
I used to use them a long while back when nothing else would
come close. Now that NiMH is around i dont need them.
k7elp60:
I wouldnt mind taking a look at your masterpiece if you provide a link
or email me a copy.
LEDs vs Bulbs, LEDs are winning.
I should clarify my term of shelf life for rechargeable batteries. In my terms the shelf life is when they have self discharged to the point they may not be useable.Robert Reed wrote:Jan Zap
"K7elp60
"Lead-Acid have a shelf life of about 6 months after fully charged. This time varies between manufacturers and the temperature at which they are stored. I have found to float them between 2.25 and 2.3 V per cell they will also never over charge. The only ones you have to limit the charge current with these voltages is the ones that are 4 AH (amp/hours) and less."
I have always floated my lead acids at 13.2 volts as you have described and even indefinately to the batts. end of life (6-7 years) and no problems. One thing I would like to compare notes with you on - years ago I read some literature from one of the major manufacturers of lead acid batterys
on self discharge rates of automotive batterys (50 amp hour size) and it was determined that these style batterys have a self discharge rate of one milliamp per amp hour of capacity. So using that info, I have always designed my chargers to trickle charge at 50 milliamps after initial charging is shut down. Of course technology changes by the month anymore and this may be outdated for todays batterys. Do you have any new or additional notes on that subject?
I have seen Ni-Cads, NiMh and Lead-acid exceed the recommendations by the specific manufacturer.
I think as manufacturers retool or set up new factories they find ways to
improve the charastics of batteries.
About the best handbook on Lead-acid batteries that I have found is the one by Power-Sonic. If you go to http://www.batteryweb.com/powersonic.cfm
then scroll down to Power-Sonic Technical Handbook. This is in PDF format and is about 250kb.
I have found with Lead-acid if they are float charged between 2.25 and 2.3 volts per cell they will only draw the necessary current to keep them charged. At this float level they are generally fully charged when the charge current drops to C/100.
Ned
Being an avid radio control participant (large planes) battery care and reliability is of prime importance. Check out www.rcbatteryclinic.com for some very good advice on the care of all types of batteries. You will get more missinformation on batteries than on most any other subject on the web so be carefull who you believe. As Regan said "Trust but verify".
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