Burning smell when charging???

[illfixit]

I'm working on a Western Rivers Predation game caller. Bought it second hand from ebay and worked the first time. Then wouldn't turn on, charge nothing. Bought a new battery pack 8.4v 1300mah and it worked on an outing then sat for about 6 months, then nothing. I disassembled it to find black wire to the battery pack was disconnected from the board, I soldered that back along with the charging port as that seemed loose. Then it worked with the new and old battery, also charged from the charging port. I then replaced the ends on the original battery 8.4v 400ma and everything worked for two outings. Left it out in the truck last night, now nothing, won't turn on charge nothing. Just get a burning smell when I plug in the charger!
I tested the charger that I thought was the original ( Csec AC adaptor 12vdc 400mA) and it charged at about 12volts then 25 volts back and forth and got really HOT.
The one I'm using now is a 12vdc 1A that stays constant and seems to react with the unit as it says charge complete. The other one doesn't now. Anyone have a solution???

 

[Harald Kapp]

The one I'm using now is a 12vdc 1A that stays constant and seems to react with the unit as it says charge complete. The other one doesn't now. Anyone have a solution???

The charger says "charge complete", what does the caller unit say? If it works, then I'd suspect the first charger is defect, as is implied by the 25V you were seeing.

If the caller doesn't work, chances are that the high voltage from the first charger did some damage to the electronics.

As there are many products on the Western River site, it will help us if you tell us the relevant part numbers. See here (charger) and here (caller).

 

[illfixit]

Thanks Harald, Its the Western Rivers Predation Caller model number 789, serial number; W000274 made around 2010 or before. I just talked to Western rivers and he said after the battery gets below 4 volts the board won't charge it and he has put hundreds of direct charging ports directly to the battery and charged for only 3 hours. And also he confirmed the Csec 400ma charger was the right one, the one that is pulsing 18-25volts. But to catch up with what I've done, I disassembled the unit once again to find that the battery +/- terminals on the board had melted solder touching each other. I cleaned it up re-assembled and then It acted like the recall description, where everyone described it would charge for a few seconds and then say charge complete on the unit. To answer your question the charger has no light or led just a basic plain black egg shaped charger and the unit led is what has the display. I'm an idiot I thought 1A was smaller than 400mA's...

 

[illfixit]

I also wanted to ask, would a 6 AA battery pack holder that would be 9 volts, hurt this unit and how many mA's that is. Would this work in place of my 8.4v 400mA rechargeable pack?
http://www.ebay.com/itm/Battery-Pac...-Switch-DC-2-1-5-5mm-Power-Plug-/181151052707

 

[Harald Kapp]

Yur description sounds like the charging system of this unit is flawed. Maybe it's a good idea to have a charging port connected to the batery as the guy from Weestern Rivers told you.

I cannot tell you how the unit will react to a 9V battery. It is possible that it's totally fine (because there has to be an internal voltage regulator anyway), but depending on the design of the unit 9V may be too much.You could try the 9V battery and put an Ammeter in series with the battery to measure the current. Compare this current with the current from the 8.4V battery. If it is similar, then 9V will probably o.k.

how many mA's that is

It's not mA, it's mAh. The difference being mA is a unit for current, mAh is a unut for capacity. mAh is current*time and by dividing the capacity in mAh by the current in mA you get the nominal time until the battery is discharged by that current. Nominal because in reality you can expect less time due to factors like temperature, age of the battery etc.
The capacity of such a battery box is determined by the batteries you use.
A typical NiMh cell has ~2000mAh capacity (you'l find less and more, too). Since the batteries are in series, the capacity of the block is determined by the min. capacity of the single cells.
A typical alkaline cell can have from 700mAh to 3000mAh, depending on the quality and the load current (yes, depending on current).
Note that a rechargeable cell (NiCd or NiMh) has a lower voltage than an alkaline cell. 6*1.5V alkaline cells give the 9V advertised for the box. Using NimH at 12V/cel you'll get only 6*1.2V=7.2V. So instead of too high a voltage (9V) the box will power the unit only with 7.2V. You'd have to try whet´her that works. I assume that the original battery simply has 7 cells (7*1.2V=8.4V) but this is for a reason.

 

[illfixit]

Thanks All, Its working like a dream...Knock on Wood!!! Thanks for all the help. Now see my next project in the Cree Led Conversion.