Eneloop / La Crosse BC-900 'Meltdown' Failure

alfreddajero

Flashlight Enthusiast
Joined
Feb 23, 2008
Messages
1,750
Location
VA Beach.
Re: Eneloop / LaCross failure

I keep looking on the maha site to see if they came out with a new C9000 charger...lol. After doing searches on chargers and the problems that the Lacross chargers had i decided to go with Maha's instead. At least he got his monies worth on the charger.
 

SilverFox

Silver Moderator,
Staff member
Joined
Jan 19, 2003
Messages
12,449
Location
Bellingham WA
Re: Eneloop / LaCross failure

I am going to move this thread over to the smoke and fire section.

Carry on over there.

Tom
 

zipplet

Flashlight Enthusiast
Joined
Dec 11, 2006
Messages
1,139
Location
Ireland
Re: Eneloop / LaCross failure

My 2 cents:

These chargers regulate the current by switching an output stage (I believe it's a MOSFET) on and off - PWM regulation.

What appears to happen is the microcontroller crashes with the output stage switched on. As the microcontroller has crashed, the output stage stays fully on. This will cause the maximum possible current to be delivered to the bays. This may well be a rediculous value, probably as high as the wall wart is going to allow!

From there on, it's disaster as there will be no cutoff due to a crashed microcontroller. They should use something like a watchdog timer to reset the chip if this happens, then display an error.
 

Light Sabre

Enlightened
Joined
Sep 8, 2008
Messages
404
Location
Tucson, Arizona
Re: Eneloop / LaCross failure

I have both of my BC-900's version 3.2 on a UPS and haven't had any problems with them. I'm just wondering if AC line noise, disturbances, etc are raising havoc with the MC. Wondering if maybe just a line filter would do the job instead of a UPS which is probably overkill.

I never charge my NMH's at 1A, always use 500 or 700ma for AA's. Thought about building an inline fuse box. One made out of a project box that has a inlet jack for the transformer and a power cord for the charger. You would have to pick a fast/medium/slow blo fuse of the right amperage and if the charger goes full blast then the fuse will blow. If the problem is caused by a locked up MC, then replacing the fuse will get everthing back up and running and you're batteries will still be useable. If the problem is caused by a MOSFET failure where it fails shorted out, the charger is history, but you will still have your batteries.
 
Last edited:

zipplet

Flashlight Enthusiast
Joined
Dec 11, 2006
Messages
1,139
Location
Ireland
Re: Eneloop / LaCross failure

That theory has been suggested Light Sabre and I seem to remember some members saying they had better luck using a beefier third party power supply. I don't have a link to the discussion, maybe someone else can dig it up :)
 

Flatshovel

Newly Enlightened
Joined
May 3, 2008
Messages
24
Re: Eneloop / LaCross failure

Well I am in need of buying some eneloop nimh lsd batteries, but after seeing this I am not sure If I want to charge them using my BC-900 ver35 charger. I don't want to buy batteries and have the charger ruin them. Anyone one else using v35 and charging the eneloop batts and had any problems? The more I think about it I might just sell my BC-900 and purchase a Maha charger.

Joey
 

SilverFox

Silver Moderator,
Staff member
Joined
Jan 19, 2003
Messages
12,449
Location
Bellingham WA
Re: Eneloop / LaCross failure

Hello Light Saber,

I have a V32 unit also, and constantly charge at 1000 mA.

I have it set up on a heat resistant surface, and I set a timer. The first timer goes off at about 75% of full charge, and the second one goes off at roughly 100% full charge. I also have a smoke alarm nearby.

This gives me two intervention points, should they be needed.

So far, no problems.

Tom
 

Light Sabre

Enlightened
Joined
Sep 8, 2008
Messages
404
Location
Tucson, Arizona
Re: Eneloop / LaCross failure

That theory has been suggested Light Sabre and I seem to remember some members saying they had better luck using a beefier third party power supply. I don't have a link to the discussion, maybe someone else can dig it up :)

Somewhere I read that suggested that you use a 2.8V power supply instead of the 3v one provided. The lower voltage causes the MOSFETs to run cooler and thus reducing failure rate substantially.

Does anybody know what the part number of the MOSFETs are? We could find a higher power substitue part, pop the cover and replace the original ones.
 
Last edited:

MarioJP

Enlightened
Joined
Sep 2, 2009
Messages
933
Re: Eneloop / LaCross failure

so even after the eneloops have cooked. Are they still usable??.
 

alfreddajero

Flashlight Enthusiast
Joined
Feb 23, 2008
Messages
1,750
Location
VA Beach.
Re: Eneloop / LaCross failure

If they still worked they would probably have lost a considerable amount of mah.....during the cooking process.
 

TakeTheActive

Enlightened
Joined
Dec 16, 2008
Messages
830
Location
Central NJ, USA
Re: Eneloop / LaCross failure

...The charger + cells were SCORCHING hot, nearly burned my hand when I touched the cells. The LCD screen turned black, and stank to all he11 and back...

...What could have caused this?
He uses this charger all the time for nearly 6-7 years...
The MOSFET Became LOCKED in the ON Position

A few questions:
  • Was the BC-900 v32 plugged into a Surge Supressor or UPS?
    .
  • Do ANY of the slots still work?
    .
  • Was a computer or television (or washing machine or vacuum, etc...) plugged into the SAME OUTLET / CIRCUIT as the BC-900?
:thinking:

BTW, if you edit your Title to "La Crosse BC-900" more folks might find this thread in the future via the SEARCH function. :poke:
 

TakeTheActive

Enlightened
Joined
Dec 16, 2008
Messages
830
Location
Central NJ, USA
Re: Eneloop / LaCross failure

this is the firmware bug in older version, newer firmware update is purposely to address this problem...
Please provide a LINK to this acknowledged / VERIFIED 'firmware bug'.

This problem has also been reported for a BC-900 v33 and a BC-9009. IMO, it appears to be a hardware problem (see my previous post).
 

Turbo DV8

Flashlight Enthusiast
Joined
Jul 5, 2006
Messages
1,464
Location
Silicon Valley
Top