La Crosse BC-700/BC-900/BC-9009 Charger 'Meltdown' Reports

[TakeTheActive]

PLEASE *ONLY* REPLY TO THIS THREAD IF
you've personally experienced a La Crosse BC-700/BC-900/BC-9009 Charger 'Meltdown'!​

Examples:

• The plastic in the cell bay area has buckled.
• One of the 7 buttons has dropped.
• The center of the LCD display has turned black.
• Other?

For suggestions, corrections, questions, etc..., please use:
.
LaCrosse BC-9009 / BC-900 - The Melt-Downs Continue...
or
Send me a PM
.
Thanks!​

If you voted in the POLL, *PLEASE* :bow: also post a reply answering the following questions:

1.) Charger Model and Version # (i.e. BC-9009 v35):

2.) Date Charger purchased (mm/dd/yyyy):

3.) Vendor from whom Charger was purchased (i.e. Amazon.Com, Thomas Distributing, etc...):

4.) Date of Charger 'Meltdown' (mm/dd/yyyy):

5.) Frequency of use of Charger (i.e. Continuous, ~X times per day/week/month, etc...):

6.) Cell(s) being charged when 'Meltdown' occurred (i.e. Eneloop 2000mAh AA, RadioShack 750mAh AAA, etc...):

7.) Date Cell(s) purchased (mm/dd/yyyy):

8.) Approximate number of CYCLES on Cell(s):

9.) Selected Charge Rate(s) in (mA):

10.) Is your Charger plugged into either a Surge Suppressor or UPS?

11.) What, if any, high current and/or 'noisy' devices are plugged into outlets on the same circuit breaker/fuse?

12.) Where any of those devices CYCLED (i.e. turned ON from OFF, or OFF from ON) while the Charger was in operation?

13.) Enter a brief description of the Charger 'Meltdown' damage (i.e. Cell Bay buckled, MODE Button dropped, Center of LCD Display turned black, etc...):
​

NOTE #1: I intentionally BOLDED and COLORED each question INDIVIDUALLY so that when replying, the CPF member need only:

1. CLICK on 'QUOTE'.
2. Remove the extraneous text, including the beginning and ending QUOTE tags.
3. Add the appropriate answer on a NEW LINE.

Thanks! ​

NOTE #2: The Version number of your La Crosse charger is the number that's momentarily displayed on the LCD for cell #4 when you 'Boot' (Power up) your charger. The number on the bottom, we believe (discussed elsewhere on CPF), relates to the case.

AFAIK, the BC-9009 began with v35 firmware.

__________________________________________________
​

12/30/09 UPDATE #1: To the CPF members who complied with my request / instructions in the NOTE above, :twothumbs Thank You!

To those who didn't , PLEASE consider EDITING your ORIGINAL REPLY and adding your 'Meltdown' Details to this thread. For folks not 'fluent' in "vBulletin Forum Software Speak", it's as easy as sssh: I've been using Firefox for so long now I HOPE these instructions, or something similar, work in Internet Explorer):

1. Go to your ORIGINAL REPLY and RIGHT CLICK on 'EDIT'.
2. OPEN a NEW TAB or WINDOW in your browser (let's call it #1).
3. Go to Post #1 in this thread and RIGHT CLICK on 'QUOTE'.
4. OPEN another NEW TAB or WINDOW in your browser (let's call it #2).
5. COPY the 13 BOLD Maroon Questions from #2 into #1.
6. In #1:
   • ADD the appropriate answer to each question on a NEW LINE.
   • DELETE the text from your ORIGINAL REPLY.
   • CLICK 'Preview Changes' to verify everything looks correct.
   • If it does, CLICK 'Save Changes' to complete the EDIT.

Even if it's been YEARS since the incident, the DETAILS, to the best of your recollection, are what's going to help identify the problem. :thinking:​

__________________________________________________
​

12/30/09 UPDATE #2: In response to a PM'd request from ShawnLam, a NEW and *VERY* 'Safety Conscious' CPF member, I added:

.
One of the challenges for me dealing with this problem is that it is mainly a US problem. La Cross chargers are not easily available in Canada, except previously from US online retailers, which is how I obtained mine.

I verified with our Provincial regulations branch, the BC Safety Authority, and was told it is not even legal for a BC retailer to sell this battery charger in BC as it does not have a recognized 3rd party safety certification. The CE mark La Cross displays is a self-assessed mark that is not equivalent to UL, CSA, or dozens of others.

Unfortunately in the US there are no national rules for electronics certification of this class of devide, although I have not looked into any State regulations as there are just too many.

The Amazon spokesperson I spoke with told me that they do not have any safety requirements from their retailers but I did let them know that we have safety requirements in Canada.

Although I don't consider my work a big victory yet as the product was only off the Amazon marketplace for a few hours, it is no longer being sold outside the US and at least not available to any Canadians.

Also being Canadian it would be too difficult for me to start any legal action and fortunately no one has been hurt or property damaged (that has been reported) so damages would be limited to a simple refund of money spent.

The other issue is that there just aren't enough people reporting their meltdowns to the US Consumer Product Safety Commission, even though the online form only takes 3 minutes and you are allowed to remain anonymous. In all these years of meltdowns, I was the first to report anything to them. We all know there are many more with meltdowns because they have posted on Amazon, CPF, and returned their melted chargers to Thomas Distributing (2 confirmed) but until they report to the US CPSC that simply isn't enough.

I just hope La Crosse can figure out their problem, but how optimistic can I be? It isn't an entirely new problem, it is just that we are making more noise than before and it is getting worse.

For more ShawnLam-specific 'Meltdown' Details, please also see: Search this Thread: | Advanced Search | User Name: ShawnLam (for the related 'Discussion Thread': LaCrosse BC-9009 / BC-900 - The Melt-Downs Continue...).

NOTE: At this point in time, I don't know if the above 'Search this Thread' LINK depends on a COOKIE on my PC, or if the imbedded SEARCHID will eventually 'timeout', or if it will even work from YOUR PC. I will test it from another PC on my LAN 'shortly' (yet another 'Experiment' into how vBulletin works - "Nothing Ventured, Nothing Gained" ).

 

[mitro]

1.) Charger Model and Version # (i.e. BC-9009 v35):

BC-9009 v35

2.) Date Charger purchased (mm/dd/yyyy):

Purchased 11/3/09

3.) Vendor from whom Charger was purchased (i.e. Amazon.Com, Thomas Distributing, etc...):

Amazon.com

4.) Date of Charger 'Meltdown' (mm/dd/yyyy):

Around 12/12/09

5.) Frequency of use of Charger (i.e. Continuous, ~X times per day/week/month, etc...):

Couple times a day on avg.

6.) Cell(s) being charged when 'Meltdown' occurred (i.e. Eneloop 2000mAh AA, RadioShack 750mAh AAA, etc...):

Duracell Pre-charged 2000mAh (White top rebadged Eneloop)

7.) Date Cell(s) purchased (mm/dd/yyyy):

Approximately 12/1/09

8.) Approximate number of CYCLES on Cell(s):

2 or 3

9.) Selected Charge Rate(s) in (mA):

4 cells @ 1000mA

10.) Is your Charger plugged into either a Surge Suppressor or UPS?

No. Plugged into the wall.

11.) What, if any, high current and/or 'noisy' devices are plugged into outlets on the same circuit breaker/fuse?

A pump for a very small fish tank was plugged in the other outlet. Not sure what else is on that circuit.

12.) Where any of those devices CYCLED (i.e. turned ON from OFF, or OFF from ON) while the Charger was in operation?

Not that I know of, but it may be possible.

13.) Enter a brief description of the Charger 'Meltdown' damage (i.e. Cell Bay buckled, MODE Button dropped, Center of LCD Display turned black, etc...):

Mine hasn't done a total meltdown (only have a button (#4) that sunk a bit). The PCB looks ok, but it got very hot. Luckily I caught it before it completely fried.

 

[lolzertank]

1.) Charger Model and Version # (i.e. BC-9009 v35):

BC-9009 v35

2.) Date Charger purchased (mm/dd/yyyy):

12/09/09

3.) Vendor from whom Charger was purchased (i.e. Amazon.Com, Thomas Distributing, etc...):

Amazon

4.) Date of Charger 'Meltdown' (mm/dd/yyyy):

12/10/09 and 12/11/09

5.) Frequency of use of Charger (i.e. Continuous, ~X times per day/week/month, etc...):

At the time, continuous

6.) Cell(s) being charged when 'Meltdown' occurred (i.e. Eneloop 2000mAh AA, RadioShack 750mAh AAA, etc...):

Rayovac 4.0 AA and the included AA cells

7.) Date Cell(s) purchased (mm/dd/yyyy):

Included cells - self explanatory
Rayovac 4.0 - October?

8.) Approximate number of CYCLES on Cell(s):

Included cells - 0
Rayovac 4.0 - 10

9.) Selected Charge Rate(s) in (mA):

700mA for included cells
1A for Rayovac 4.0

10.) Is your Charger plugged into either a Surge Suppressor or UPS?

No

11.) What, if any, high current and/or 'noisy' devices are plugged into outlets on the same circuit breaker/fuse?

Nothing

12.) Where any of those devices CYCLED (i.e. turned ON from OFF, or OFF from ON) while the Charger was in operation?

No

13.) Enter a brief description of the Charger 'Meltdown' damage (i.e. Cell Bay buckled, MODE Button dropped, Center of LCD Display turned black, etc...):

2 and 3 buttons dropped
​

 

[RaVeN38571]

1.) Charger Model and Version # (i.e. BC-9009 v35):
BC-9009 v35
2.) Date Charger purchased (mm/dd/yyyy):
11/10/2009
3.) Vendor from whom Charger was purchased (i.e. Amazon.Com, Thomas Distributing, etc...):
Amazon.com
4.) Date of Charger 'Meltdown' (mm/dd/yyyy):
11/18/2009
5.) Frequency of use of Charger (i.e. Continuous, ~X times per day/week/month, etc...):
24hrs/1 day
6.) Cell(s) being charged when 'Meltdown' occurred (i.e. Eneloop 2000mAh AA, RadioShack 750mAh AAA, etc...):
Duracell Whitetops/made in Japan
7.) Date Cell(s) purchased (mm/dd/yyyy):
10/04/2009
8.) Approximate number of CYCLES on Cell(s):
None
9.) Selected Charge Rate(s) in (mA):
1000ma
10.) Is your Charger plugged into either a Surge Suppressor or UPS?
No
11.) What, if any, high current and/or 'noisy' devices are plugged into outlets on the same circuit breaker/fuse?
TV, Garbage disposal
12.) Where any of those devices CYCLED (i.e. turned ON from OFF, or OFF from ON) while the Charger was in operation?
Do not know
13.) Enter a brief description of the Charger 'Meltdown' damage (i.e. Cell Bay buckled, MODE Button dropped, Center of LCD Display turned black, etc...):
Cell bay 2 button sunk in, Lcd turned black on right hand side

 

[ShawnLam]

1.) Charger Model and Version # (i.e. BC-9009 v35):
BC-9009 V35

2.) Date Charger purchased (mm/dd/yyyy):
24/10/2009

3.) Vendor from whom Charger was purchased (i.e. Amazon.Com, Thomas Distributing, etc...):
Amazon.com

4.) Date of Charger 'Meltdown' (mm/dd/yyyy):
18/12/2009

5.) Frequency of use of Charger (i.e. Continuous, ~X times per day/week/month, etc...):
3x per week

6.) Cell(s) being charged when 'Meltdown' occurred (i.e. Eneloop 2000mAh AA, RadioShack 750mAh AAA, etc...):
2x Eneloop AA on outside slots.

7.) Date Cell(s) purchased (mm/dd/yyyy):
01/09/2009

8.) Approximate number of CYCLES on Cell(s):
20

9.) Selected Charge Rate(s) in (mA):
1,000 mA

10.) Is your Charger plugged into either a Surge Suppressor or UPS?
Surge Suppressor

11.) What, if any, high current and/or 'noisy' devices are plugged into outlets on the same circuit breaker/fuse?
No

12.) Where any of those devices CYCLED (i.e. turned ON from OFF, or OFF from ON) while the Charger was in operation?
n/a

13.) Enter a brief description of the Charger 'Meltdown' damage (i.e. Cell Bay buckled, MODE Button dropped, Center of LCD Display turned black, etc...):
Mode button dropped, charger overheated and started smoking.
​

 

[N162E]

BC-900 v32 back when they first came out. Purchased from Thomas. I had an IR thermometer close by and measured cell temps over 400 degrees. The buttons all pushed down into the case with slight pressure. LaCrosse did not want to deal with the problem and refused to send me a new charger. They told me what I described could not have happened. I sent them the charger, they sent me a new one. My meltdown happened with the LaCrosse AA cells. I get the feeling LaCrosse is in business to sell products only. They know very little about their products and care even less about service, visit them at the Shot Show and you will agree with me. I own and use 3-BC 900s and 2-BC 700s. In spite of my "LaCrosse Meltdown" and problem with LaCrosse I still think they make the best charger out there.

 

[n2deep]

1.) Charger Model and Version # (i.e. BC-9009 v35):
BC-9009 V 35

2.) Date Charger purchased (mm/dd/yyyy):
12/10/2009

3.) Vendor from whom Charger was purchased (i.e. Amazon.Com, Thomas Distributing, etc...):
Amazon

4.) Date of Charger 'Meltdown' (mm/dd/yyyy):
12/25/2009

5.) Frequency of use of Charger (i.e. Continuous, ~X times per day/week/month, etc...):
1x day

6.) Cell(s) being charged when 'Meltdown' occurred (i.e. Eneloop 2000mAh AA, RadioShack 750mAh AAA, etc...):
Eneloop 200mah

7.) Date Cell(s) purchased (mm/dd/yyyy):
12/18/2009

8.) Approximate number of CYCLES on Cell(s):
1
9.) Selected Charge Rate(s) in (mA):
1000 ma
10.) Is your Charger plugged into either a Surge Suppressor or UPS?
no
11.) What, if any, high current and/or 'noisy' devices are plugged into outlets on the same circuit breaker/fuse?
nothing else
12.) Where any of those devices CYCLED (i.e. turned ON from OFF, or OFF from ON) while the Charger was in operation?
no
13.) Enter a brief description of the Charger 'Meltdown' damage (i.e. Cell Bay buckled, MODE Button dropped, Center of LCD Display turned black, etc...):
Mode button dropped and LCD turned black

 

[kramer5150]

1.) Charger Model and Version # (i.e. BC-9009 v35):
BC-900 v32

2.) Date Charger purchased (mm/dd/yyyy):
8-9 years ago

3.) Vendor from whom Charger was purchased (i.e. Amazon.Com, Thomas Distributing, etc...):
Thomas or batteryspace I am not sure

4.) Date of Charger 'Meltdown' (mm/dd/yyyy):
11/24/09

5.) Frequency of use of Charger (i.e. Continuous, ~X times per day/week/month, etc...):
Daily

6.) Cell(s) being charged when 'Meltdown' occurred (i.e. Eneloop 2000mAh AA, RadioShack 750mAh AAA, etc...):
4xEneloop AA

7.) Date Cell(s) purchased (mm/dd/yyyy):
All within the past 2.5 years

8.) Approximate number of CYCLES on Cell(s):
No way of knowing eactly, At least 10-15 times each

9.) Selected Charge Rate(s) in (mA):
500ma

10.) Is your Charger plugged into either a Surge Suppressor or UPS?
Surge protector

11.) What, if any, high current and/or 'noisy' devices are plugged into outlets on the same circuit breaker/fuse?
Fluorescent lighting ~100 watts total

12.) Where any of those devices CYCLED (i.e. turned ON from OFF, or OFF from ON) while the Charger was in operation?
No, room lights were in the ON position

13.) Enter a brief description of the Charger 'Meltdown' damage (i.e. Cell Bay buckled, MODE Button dropped, Center of LCD Display turned black, etc...):
Cells became scorching hot, hot enough to melt the plastic shrink wrap and turn it dry and flaky. The cells were scalding hot, too hot to touch. The charger LCD turned black

Thread and pics here.

http://www.candlepowerforums.com/vb/showthread.php?t=250545

 

[arteitle]

1.) Charger Model and Version # (i.e. BC-9009 v35):

BC-9009 v. 35

2.) Date Charger purchased (mm/dd/yyyy):

Received 01/05/2010

3.) Vendor from whom Charger was purchased (i.e. Amazon.Com, Thomas Distributing, etc...):

Amazon.com

4.) Date of Charger 'Meltdown' (mm/dd/yyyy):

01/05/2010

5.) Frequency of use of Charger (i.e. Continuous, ~X times per day/week/month, etc...):

First usage (test cycle)

6.) Cell(s) being charged when 'Meltdown' occurred (i.e. Eneloop 2000mAh AA, RadioShack 750mAh AAA, etc...):

Four 2600 mAh LaCrosse-supplied AA cells

7.) Date Cell(s) purchased (mm/dd/yyyy):

01/05/2010, included with charger

8.) Approximate number of CYCLES on Cell(s):

One

9.) Selected Charge Rate(s) in (mA):

1000 mA

10.) Is your Charger plugged into either a Surge Suppressor or UPS?

No

11.) What, if any, high current and/or 'noisy' devices are plugged into outlets on the same circuit breaker/fuse?

Nothing comes to mind

12.) Where any of those devices CYCLED (i.e. turned ON from OFF, or OFF from ON) while the Charger was in operation?

No

13.) Enter a brief description of the Charger 'Meltdown' damage (i.e. Cell Bay buckled, MODE Button dropped, Center of LCD Display turned black, etc...):

Odor of burning plastic, sinking of buttons #2 and #3 caused by softening of plastic supports.

 

[Diego]

1.) Charger Model and Version # (i.e. BC-9009 v35):

BC-9009 v.35 what I believe to be a manufacturing date 8N9 (same as the one you show in your picture)

2.) Date Charger purchased (mm/dd/yyyy):

12/12/2009

3.) Vendor from whom Charger was purchased (i.e. Amazon.Com, Thomas Distributing, etc...):

Amazon.com

4.) Date of Charger 'Meltdown' (mm/dd/yyyy):

01/12/2010

5.) Frequency of use of Charger (i.e. Continuous, ~X times per day/week/month, etc...):

5th set of AA batteries... about 3-4 times a week. It's new and I've been testing it out to increase my knowledge and confidence

6.) Cell(s) being charged when 'Meltdown' occurred (i.e. Eneloop 2000mAh AA, RadioShack 750mAh AAA, etc...):

Four 2300mAh NiMH Energizer AA cells

7.) Date Cell(s) purchased (mm/dd/yyyy):

12/??/2009

8.) Approximate number of CYCLES on Cell(s):

2

9.) Selected Charge Rate(s) in (mA):

700 mA

10.) Is your Charger plugged into either a Surge Suppressor or UPS?

Yes, APC SmartUPS 1400XL

11.) What, if any, high current and/or 'noisy' devices are plugged into outlets on the same circuit breaker/fuse?

Not really, low end server and Cisco networking equipment

12.) Where any of those devices CYCLED (i.e. turned ON from OFF, or OFF from ON) while the Charger was in operation?

No

13.) Enter a brief description of the Charger 'Meltdown' damage (i.e. Cell Bay buckled, MODE Button dropped, Center of LCD Display turned black, etc...):

#3 bay button sunk and rattles free, #4 bay button sunk 1/2 way. Batteries still discharging, meltdown happened during discharge 350mA part of Test mode

 

[Jclem451]

I have the 9009, ver 32, which doesn't seem to be a choice here, so I picked the only model that has a ver 2 as a choice. I got it from Amazon Dec,2009. It came with 4 AA, and 4 AAA batteries. I put the 2600 mAh AA batteries in, plugged it into an empty outlet and left the house for a couple hours. When I returned, the charger was smoking hot,as were the 2 center batteries, the display above the batteries was black, and the 2 middle buttons in the row of 4, were melted and had dropped down. I let it cool, and tried it again, and it still seems to work, but it is going back to Amazon pronto. I am lucky to still have a house.

 

[Diego]

Well, this is the replacement for the last one that melted. I'm 0 for 2.

1.) Charger Model and Version # (i.e. BC-9009 v35):

BC-9009 v.35 what I believe to be a manufacturing date 9N9

2.) Date Charger purchased (mm/dd/yyyy):

1/7/2010

3.) Vendor from whom Charger was purchased (i.e. Amazon.Com, Thomas Distributing, etc...):

Amazon.com

4.) Date of Charger 'Meltdown' (mm/dd/yyyy):

01/12/2010

5.) Frequency of use of Charger (i.e. Continuous, ~X times per day/week/month, etc...):

1st battery

6.) Cell(s) being charged when 'Meltdown' occurred (i.e. Eneloop 2000mAh AA, RadioShack 750mAh AAA, etc...):

One 2300mAh NiMH Energizer AA cells

7.) Date Cell(s) purchased (mm/dd/yyyy):

12/??/2009

8.) Approximate number of CYCLES on Cell(s):

2

9.) Selected Charge Rate(s) in (mA):

700 mA

10.) Is your Charger plugged into either a Surge Suppressor or UPS?

No

11.) What, if any, high current and/or 'noisy' devices are plugged into outlets on the same circuit breaker/fuse?

No

12.) Where any of those devices CYCLED (i.e. turned ON from OFF, or OFF from ON) while the Charger was in operation?

No

13.) Enter a brief description of the Charger 'Meltdown' damage (i.e. Cell Bay buckled, MODE Button dropped, Center of LCD Display turned black, etc...):

#13 bay button sunk 1/2 way. Battery still charged, meltdown happened during discharge 350mA part of Test mode

 

[TakeTheActive]

La Crosse BC-700/BC-900/BC-9009 Charger 'Meltdown' - La Crosse Responded

La Crosse Responded - 02/11/2010​

Just received this from Amazon:

Greetings from Amazon.com.

We have recently learned that La Crosse Technology, Inc. is voluntarily replacing the AC adapters used with La Crosse Technology BC-9009 AlphaPower Battery Chargers sold between October 1, 2009 and January 15, 2010. Our records indicate that you have purchased one of the La Crosse Technology BC-9009 AlphaPower Battery Chargers listed in this time frame through the Amazon.com website.

Below is a link and the verbiage that is on La Crosse Technology's web site.

AC Adapter Replacement for BC-9009 AlphaPower Battery Charger
La Crosse Technolology recently switched to a new AC adapter that meets California Energy Commission (CEC) requirements. La Crosse Technology has discovered that this new AC adapter has an increased voltage output; therefore we are replacing the AC adapter free of charge.

The AC adapter that needs replacement can be identified by the Roman number IV on the adapter.

Please click the following link to supply us with your shipping information in order for La Crosse Technology to send you a replacement adapter.

https://www.lacrossetechnology.com/support/bc9009

If you purchased this item as a gift for someone, please notify the recipient immediately and provide them with the information above.

We regret the inconvenience that this has caused you but trust you will understand that the safety of our customers is our highest priority.

Thanks for shopping at Amazon.com.

__________________________________________________​

AC Adapter Replacement for the BC-9009 AlphaPower Battery Charger

La Crosse Technology recently switched to a new AC adapter that meets California Energy Commission (CEC) requirements.

La Crosse Technology has discovered that this new AC adapter has an increased voltage output; therefore we are replacing the AC adapter free of charge.

If your BC-9009 AC adapter has the Roman number IV in the location shown in the diagram to the right, please complete the form below so we can ship you a replacement AC adapter free of charge.

You should receive your replacement AC adapter about a month after submitting an order.

__________________________________________________​

Now that we know WHAT component La Crosse changed...

I was recently refreshing some solar garden light cells with my pair of BC-900s when a turn of events led to an interesting discovery. I was running one charger on the stock power supply and the other on this supply. I had already done all of the mods described in this thread, as well as the temperature sensor mode described in this thread (see posts 38, 40, and 41). Anyway, when charging some cells at 1000 mA (with a fan blowing on them, of course), the current on one of the charging stations dropped very low, and the bottom of the charger right under it was extremely hot. I removed the cell right away. Apparently the MOSFET had gone into thermal runaway to the point that with its increased internal resistance it just couldn't deliver the set current. Surprisingly, the charger worked fine upon cooling so the damage wasn't permanent but some have had their chargers go into complete meltdown. I did have to fix a melted button shaft however.

Anyway, the problem occurred on the charger with the alternate supply. As mentioned, the circuit board does get notably hotter when using this supply as opposed to the stock supply. However, the charger gets too hot on 1000 mA even with the stock supply. This got me thinking that maybe the BC-900 can happily operate at less than the 3 volts of the stock power supply so I started experimenting. To make a long story short the BC-900 will happily operate at 2.5 or so volts while still being capable of delivering 1000 mA. Any less than that and it works, but can't provide 1000 mA to the cells (although lower current settings work fine)...

...In the BC-900 design, it uses a very small package MOSFET (SOT23) as a linear step-down regulator which has to disspate power due to the difference in voltage between the power supply (4V) and the battery (1.5V). The power disspated by the MOSFET is the current times the voltage difference. At peak charging current, the wattage disspated is considerable...

Hence the reason why I'm now running my two BC-900s on a 2.8V power supply. See this thread. The stock supply is around 3.0 to 3.1 volts. My modded supplies give about 2.8 volts no load and about 2.6 volts at the charger when all four charging stations are at 1000 mA. The MOSFETs get warm but not very hot like before. I agree 100% that the MOSFETs are overstressed at the stock power supply voltage. In fact, it really concerned me the first time I noticed how hot they were getting.

...It's possible that the relevant regulation circuitry inside the charger is a switching circuit instead of linear, which could be less sensitive to a slightly higher input voltage.

Unless LaCrosse changed something on their newer BC-900s, there is no switching circuit. The PCBs on the ones I modded had absolutely no inductors. It's a pure linear circuit, which is why my power supply mod reduced the operating temperatures. I'll also add that my modded BC-900s are still working fine, although I used them a lot less once I purchased a pair of MH-C9000s.

ON Semiconductor: NTGS3443T1 MOSFET Specifications - PDF Format - Thanks Russel!

La Crosse BC-700 & BC-900 Photos (P/S & PCB) - Russel​

 

[blueseer]

I bought my La Crosse BC 900 (no version was printed) at around 2002 from Thomas Distributing (I'm also in Canada). It had been working perfectly fine from the last 8 years. Last year, when I was traveling in Brazil, it melted down. The battery was 2 Engerizer 2300mah (the battery had been charged many times). I didn't recall too many connections on the wall socket. The two batteries was overheated. The second button sink a tiny bit. It wasn't too bad. The charger is still working and I'm still using it today....

Despite of this, I still think this is one of the best gadget I have bought. I am hoping to buy another Lacrosse (even though the current one is still working, but the melt down is a bit worrying).

None of my gadgets I bought in 2002 survived until today (and I bought lots of gadgets). The meltdown seems very strange, it all happened in the same year (2009)... It was heavily used in the last 8 years and never gave any problem. I almost suspected there was a timer in there that cause the melt down the same year.

Anyway, please let me know if the meltdown is still happening, I am hoping to buy a replacement soon.