Anyone seen this La Crosse BC-900 Charger, part 2
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Wingerr
Flashlight Enthusiast
Re: La Crosse BC-900 Charger, Part II
The idea, I think, was to determine how fully he charged the cells using the other charger, not to see what the BC will charge it to. You can't view batteries as capacitors, which is where this idea of "topping up to see how much it takes to fill" comes from. They're *not* like cups holding water, where you can see how fully another faucet filled it, by adding a measured amount until it's full. Just doesn't work that way; more like using a spray head to fill it, with some unknown spray going outside the cup as you fill it. Only a discharge cycle can tell you the true capacity, and even that can change on the next cycle, if it was in need of a refresh.
The idea, I think, was to determine how fully he charged the cells using the other charger, not to see what the BC will charge it to. You can't view batteries as capacitors, which is where this idea of "topping up to see how much it takes to fill" comes from. They're *not* like cups holding water, where you can see how fully another faucet filled it, by adding a measured amount until it's full. Just doesn't work that way; more like using a spray head to fill it, with some unknown spray going outside the cup as you fill it. Only a discharge cycle can tell you the true capacity, and even that can change on the next cycle, if it was in need of a refresh.
Brock
Flashaholic
Re: La Crosse BC-900 Charger, Part II
Right. You can take a battery that was charged in the BC-900 take it out, put it back in and it will put 100-300 back in again every time. Most of that is lost in heat and some goes in to "toping" off the cell. So unless you know a certain cell always puts in say 150mA from full you can't really tell.
All in all I really like the charger, I have found a bunch of bad cells and tried to "refresh" them, most with no luck, but know I know what's going on. That makes it worth it to me.
Right. You can take a battery that was charged in the BC-900 take it out, put it back in and it will put 100-300 back in again every time. Most of that is lost in heat and some goes in to "toping" off the cell. So unless you know a certain cell always puts in say 150mA from full you can't really tell.
All in all I really like the charger, I have found a bunch of bad cells and tried to "refresh" them, most with no luck, but know I know what's going on. That makes it worth it to me.
Wingerr
Flashlight Enthusiast
Re: La Crosse BC-900 Charger, Part II
Well, if that's all you're looking to find out, and they're the same type of batteries and were equally charged, you should be able to determine which one was used by just running a charge cycle on it. In that case, you're just comparing the two and not really interested in precise numbers, so that would work.
Well, if that's all you're looking to find out, and they're the same type of batteries and were equally charged, you should be able to determine which one was used by just running a charge cycle on it. In that case, you're just comparing the two and not really interested in precise numbers, so that would work.
Re: La Crosse BC-900 Charger, Part II
I am interested in precise numbers. But English is not my mothers language, and I have no theoretical background. So sometimes it is a little difficult to write exactly what I think and want to ask.
/ubbthreads/images/graemlins/banghead.gif
At first I will read this whole thread carefully I think a lot of questions are answered yet.
When something is not clear to me i'm happy to ask.
I am interested in precise numbers. But English is not my mothers language, and I have no theoretical background. So sometimes it is a little difficult to write exactly what I think and want to ask.
/ubbthreads/images/graemlins/banghead.gif
At first I will read this whole thread carefully I think a lot of questions are answered yet.
When something is not clear to me i'm happy to ask.
Re: La Crosse BC-900 Charger, Part II
I visited the "Battery University".
One thing puzzles me:
I did read and hear many times: The best way to charge batteries is taking about 9 hours to charge and so avoiding high temperatures and save battery life.
On the "University" is explained the best way to charge is Fast charging say for about 1 hour.
This should give best results and saves the batteries.It should avoid crystalline formation.
I would like to hear your comments on that.
I visited the "Battery University".
One thing puzzles me:
I did read and hear many times: The best way to charge batteries is taking about 9 hours to charge and so avoiding high temperatures and save battery life.
On the "University" is explained the best way to charge is Fast charging say for about 1 hour.
This should give best results and saves the batteries.It should avoid crystalline formation.
I would like to hear your comments on that.
Re: La Crosse BC-900 Charger, Part II
Second question (for the moment):
I did read on the same source:
New nickel-based batteries should be trickle-charged for 24 hours prior to use. Trickle charge brings all cells to equal charge level because each cell self-discharges at a different rate. Trickle charge also redistributes the electrolyte to remedy dry spots on the separator brought on by gravitation of the electrolyte during long storage.
Can you please comment on that?
Second question (for the moment):
I did read on the same source:
New nickel-based batteries should be trickle-charged for 24 hours prior to use. Trickle charge brings all cells to equal charge level because each cell self-discharges at a different rate. Trickle charge also redistributes the electrolyte to remedy dry spots on the separator brought on by gravitation of the electrolyte during long storage.
Can you please comment on that?
SilverFox
Flashaholic
Re: La Crosse BC-900 Charger, Part II
Hello Hadu,
When charging NiMh cells, there is a slight voltage drop when the cell is fully charged. At low charge rates it is very difficult to measure that drop. If you charge at a higher rate, it is easier to measure it. If you do not stop the charge, the cell heats up and you damage it.
Another benefit from a faster charge it is that it breaks down crystalline formation. This is also a benefit from a discharge cycle down to 0.8 - 1.0 volts per cell.
The La Crosse charger allows you to choose several charge rates to accommodate several different capacity cells.
When you put several cells together to form a battery, the cells are sometimes not evenly matched. Applying a slow charge for a set amount of time (using time to avoid an overcharge rather than using a drop in voltage) will bring the cells in the battery all up to an even state of charge.
Long term storage is considered (to me) to be for periods of over 1 year.
First of all, it is not wise to purchase extra rechargeable cells if you do not need them. They are improving all the time and a good price on todays technology will be money poorly spent a year from now. With fast chargers that seem to work very well, you can get by with even fewer cells.
If you do happen to have some cells that have been stored for a long time, several slow cycles would be the best way to bring them back to life. I would treat them like new cells and do a few break in cycles and just realize that they probably will not be up to their new peak performance.
Once again the La Crosse charger with its refresh function is excellent for doing this.
Tom
Hello Hadu,
When charging NiMh cells, there is a slight voltage drop when the cell is fully charged. At low charge rates it is very difficult to measure that drop. If you charge at a higher rate, it is easier to measure it. If you do not stop the charge, the cell heats up and you damage it.
Another benefit from a faster charge it is that it breaks down crystalline formation. This is also a benefit from a discharge cycle down to 0.8 - 1.0 volts per cell.
The La Crosse charger allows you to choose several charge rates to accommodate several different capacity cells.
When you put several cells together to form a battery, the cells are sometimes not evenly matched. Applying a slow charge for a set amount of time (using time to avoid an overcharge rather than using a drop in voltage) will bring the cells in the battery all up to an even state of charge.
Long term storage is considered (to me) to be for periods of over 1 year.
First of all, it is not wise to purchase extra rechargeable cells if you do not need them. They are improving all the time and a good price on todays technology will be money poorly spent a year from now. With fast chargers that seem to work very well, you can get by with even fewer cells.
If you do happen to have some cells that have been stored for a long time, several slow cycles would be the best way to bring them back to life. I would treat them like new cells and do a few break in cycles and just realize that they probably will not be up to their new peak performance.
Once again the La Crosse charger with its refresh function is excellent for doing this.
Tom
Re: La Crosse BC-900 Charger, Part II
Pffff, quite an answer, Tom. Thanks...
Your answer leaves me with a couple of questions:
1. When loading a battery is optimal when charging for about 1 hour it leaves me no alternative to load at 1800 mA for a 2300 mAh battery that would give a charging time of about 75 minutes.
2.You write: best to discharge till about 1.0 Volt, is this happening automatic when discharging with the La Crosse? Or is the battery almost completely emptied?
3.When trickle load is advised for new batteries how do I do that? I read in the manual the lowest charge is with 200 mA.
What do you mean by a few slow cycles? Can you give a example? Is it automatic done with the refresh function?
Thanks in advance.
Pffff, quite an answer, Tom. Thanks...
Your answer leaves me with a couple of questions:
1. When loading a battery is optimal when charging for about 1 hour it leaves me no alternative to load at 1800 mA for a 2300 mAh battery that would give a charging time of about 75 minutes.
2.You write: best to discharge till about 1.0 Volt, is this happening automatic when discharging with the La Crosse? Or is the battery almost completely emptied?
3.When trickle load is advised for new batteries how do I do that? I read in the manual the lowest charge is with 200 mA.
What do you mean by a few slow cycles? Can you give a example? Is it automatic done with the refresh function?
Thanks in advance.
greenlight
Flashlight Enthusiast
Re: La Crosse BC-900 Charger, Part II
Is it wise to totally drain nimh when using them?
Is it wise to totally drain nimh when using them?
SilverFox
Flashaholic
Re: La Crosse BC-900 Charger, Part II
Hello Hadu,
In life there are compromises...
There are also compromises in battery charging... /ubbthreads/images/graemlins/grin.gif
I charge my 2300 mAh cells at 500 mA and am very pleased with the results. If I am in a hurry, I go faster. My procedure is based on giving a high enough current so the drop in voltage at the end of the charge can be detected, but also I am trying to minimize the heat generated in the cell. After a few cycles, I will simply let the La Crosse charge at its default rate (200 mA) if I am not in a hurry.
The La Crosse terminates the discharge cycle at about 0.9 volts automatically. With NiMh and NiCd chemistries, the cell is considered empty when the voltage drops to 0.8 volts under load. When you remove the load, the voltage will jump up to a little over 1.0 volts depending on how big the load is.
The 200 mA rate would be considered a trickle charge for 2300 mAh cells. On the other hand, if you had 500 mAh cells, you would not be able to trickle charge them on the La Crosse charger.
It takes a few cycles from full charge to full discharge for NiMh cells to reach their maximum capacity. These cycles can be done by using them in an application, or by using the refresh cycle on the La Crosse charger. There are also manual ways of doing this, but it can take additional test equipment and more involvement on your part. I find the refresh cycle on the La Crosse very convenient.
Tom
Hello Hadu,
In life there are compromises...
There are also compromises in battery charging... /ubbthreads/images/graemlins/grin.gif
I charge my 2300 mAh cells at 500 mA and am very pleased with the results. If I am in a hurry, I go faster. My procedure is based on giving a high enough current so the drop in voltage at the end of the charge can be detected, but also I am trying to minimize the heat generated in the cell. After a few cycles, I will simply let the La Crosse charge at its default rate (200 mA) if I am not in a hurry.
The La Crosse terminates the discharge cycle at about 0.9 volts automatically. With NiMh and NiCd chemistries, the cell is considered empty when the voltage drops to 0.8 volts under load. When you remove the load, the voltage will jump up to a little over 1.0 volts depending on how big the load is.
The 200 mA rate would be considered a trickle charge for 2300 mAh cells. On the other hand, if you had 500 mAh cells, you would not be able to trickle charge them on the La Crosse charger.
It takes a few cycles from full charge to full discharge for NiMh cells to reach their maximum capacity. These cycles can be done by using them in an application, or by using the refresh cycle on the La Crosse charger. There are also manual ways of doing this, but it can take additional test equipment and more involvement on your part. I find the refresh cycle on the La Crosse very convenient.
Tom
SilverFox
Flashaholic
Re: La Crosse BC-900 Charger, Part II
Hello Greenlight,
It is not necessary to completely drain NiMh cells every time you use them. I run mine down about once every 3 months.
Tom
Hello Greenlight,
It is not necessary to completely drain NiMh cells every time you use them. I run mine down about once every 3 months.
Tom
Re: Anyone seen this La Crosse BC-900 Charger, par
Hello All,
My apologies if this has been asked before. This thread is so long that I might have missed it
I recently received the lacrosse charger. Unfortunately I have trouble getting the thing to respond to the mode or current buttons. When I insert four batteries, then try to change the mode to discharge, it seems pretty random if the mode button will actually work, or not. Similar for the current button. I know the manual says I need to hold it down for a second first before I can change it. That just most of the time doesn't work.
I was wondering if someone else saw the same problem, or if my unit is defective. I'm hoping the latter so that I can get a new one since it is such an awesome charger!
Thanks for any replies!
Barthold
Hello All,
My apologies if this has been asked before. This thread is so long that I might have missed it
I recently received the lacrosse charger. Unfortunately I have trouble getting the thing to respond to the mode or current buttons. When I insert four batteries, then try to change the mode to discharge, it seems pretty random if the mode button will actually work, or not. Similar for the current button. I know the manual says I need to hold it down for a second first before I can change it. That just most of the time doesn't work.
I was wondering if someone else saw the same problem, or if my unit is defective. I'm hoping the latter so that I can get a new one since it is such an awesome charger!
Thanks for any replies!
Barthold
BVH
Flashaholic
Re: Anyone seen this La Crosse BC-900 Charger, par
Frequently, I have to push the buttons more than once and press just a bit more firmly to effect a change. I can live with it.
Frequently, I have to push the buttons more than once and press just a bit more firmly to effect a change. I can live with it.
Brock
Flashaholic
Re: Anyone seen this La Crosse BC-900 Charger, par
I ran in to this at first and found pressing on them quite firmly does the trick. It is a lot harder then you would think you have to press.
I ran in to this at first and found pressing on them quite firmly does the trick. It is a lot harder then you would think you have to press.
Wingerr
Flashlight Enthusiast
Re: La Crosse BC-900 Charger, Part II
I usually lift the unit up and just squeeze the buttons rather than push it- works much better that way.
I usually lift the unit up and just squeeze the buttons rather than push it- works much better that way.
Re: La Crosse BC-900 Charger, Part II
First of all let me say a big /ubbthreads/images/graemlins/thanks.gif to Jon for offering such a great product at a fantastic price and with very quick service during the entire transaction. Too bad CPF doesn't have a "feedback" feature for all the vendors (but then I would imagine that most of the dealers that support CPF would probably get 100% anyway). /ubbthreads/images/graemlins/thumbsup.gif
Now enough of the schmoozing /ubbthreads/images/graemlins/wink.gif. He is the straight poop for the people who are on the fence about buying this charger.
First - buy it. /ubbthreads/images/graemlins/twakfl.gif(Preferably from jsburly.com) oh - no more schmoozing..... but really for $52 shipped with 2 sets of batteries, and the adapters, and the case, and the fact that the power supply is multi voltage (for all the 110v people - that means you can take it on your trip to London with the wife /ubbthreads/images/graemlins/wink.gif ) The money you save from refreshing old cells will pay for the charger, and if you are a flashaholic with a few Mag85s lying about, it might even save enough money to upgrade out of tourist class.
2) This charger has finally done what I "tried" for years by hand..... No more meters, no more high capacity resistors to drain batteries, no more charging a cell and wondering if it is still good, no more blaming the charger for what often a bad cell in the bunch. /ubbthreads/images/graemlins/wow.gif Actually having preset charging rates. My only afterthought is that maybe I should have bought two... But then again JSBurly purchases include shipping (there I go again...).
If I had too make changes to the unit, it would be as follows:
1) Holds 9 batteries (for the Mag85)/ubbthreads/images/graemlins/buttrock.gif
2) Provide a backlight for the display so that as I sit around at night watching those old 700ma NiCds refresh, I due not have to have a flashlight(hmmm. well that IS another reason to buy a new flashlight...) /ubbthreads/images/graemlins/wink.gif
3) All other wants and needs in a battery charger are one that would cover other types of batteries (espically R123 and the rechargible CR2), and maybe a built in switching power supply....
OK fire up the PayPal!
Thanks
Stephen
First of all let me say a big /ubbthreads/images/graemlins/thanks.gif to Jon for offering such a great product at a fantastic price and with very quick service during the entire transaction. Too bad CPF doesn't have a "feedback" feature for all the vendors (but then I would imagine that most of the dealers that support CPF would probably get 100% anyway). /ubbthreads/images/graemlins/thumbsup.gif
Now enough of the schmoozing /ubbthreads/images/graemlins/wink.gif. He is the straight poop for the people who are on the fence about buying this charger.
First - buy it. /ubbthreads/images/graemlins/twakfl.gif(Preferably from jsburly.com) oh - no more schmoozing..... but really for $52 shipped with 2 sets of batteries, and the adapters, and the case, and the fact that the power supply is multi voltage (for all the 110v people - that means you can take it on your trip to London with the wife /ubbthreads/images/graemlins/wink.gif ) The money you save from refreshing old cells will pay for the charger, and if you are a flashaholic with a few Mag85s lying about, it might even save enough money to upgrade out of tourist class.
2) This charger has finally done what I "tried" for years by hand..... No more meters, no more high capacity resistors to drain batteries, no more charging a cell and wondering if it is still good, no more blaming the charger for what often a bad cell in the bunch. /ubbthreads/images/graemlins/wow.gif Actually having preset charging rates. My only afterthought is that maybe I should have bought two... But then again JSBurly purchases include shipping (there I go again...).
If I had too make changes to the unit, it would be as follows:
1) Holds 9 batteries (for the Mag85)/ubbthreads/images/graemlins/buttrock.gif
2) Provide a backlight for the display so that as I sit around at night watching those old 700ma NiCds refresh, I due not have to have a flashlight(hmmm. well that IS another reason to buy a new flashlight...) /ubbthreads/images/graemlins/wink.gif
3) All other wants and needs in a battery charger are one that would cover other types of batteries (espically R123 and the rechargible CR2), and maybe a built in switching power supply....
OK fire up the PayPal!
Thanks
Stephen
