Need Charger Cooling Fan

[aroundqube]

Kingpan KP4802WL 48 V LiFePo4 battery charger. AC in 90-120 vac, DC out 58.4Vdc 2A around 2 1/2 yrs old. Plug in the RCA charging plug to the 48v LiFePo4 battery first,then plug in ac power cord. Always get a snap at the power cord when I plug it in and the charger works fine. 2 red leds come on,1 for power and 1 for charging. The fan normally runs untill the charging light turns green. Tonight the snap when I plugged it in sounded a little louder.It was charging,but no fan. Got hot in 15 min, so I stopped and put it in the frost free refrig at 40 F to cool it down. Removed the fan ; RUNDA 12 vdc 0.12A electronics fan,2 wire . Measures 40mm x 40mm. Ohm test at the disconnected plug of the fan at 2000k is open. Fan blade unobstructed and spun freely. Does anyone know of a replacement ?

 

[wesnewell]

Google 40mm fan and take your pick. BTW, you should not have put the hot charger in the fridge. Rapid heating and cooling is what causes component failures. Like sticking hot glass into cold water or freezing plate into hot water.

 

[knighty]

and power the charger on before you plug it into the batteries, that'll stop the spark

 

[dnmun]

yes, always plug the charger in and have it powered up when you connect the battery.

you may want to test it by putting 12V through a 100 ohm resistor on the leads. it may show open but still work if it is a brushless motor. maybe.

but you need the 100 ohm resistor to replicate normal operation. the leads may be broken under the end cover where they attach to the motor.

 

[aroundqube]

Thankyou ! The charger is charging now, with a new fan that is working. Some more background of the repair. I wanted to check for 12V DC out at the pins on the board,but there is always that one tiny screw on the side that will not unscrew so that you can slide the board out of the aluminum shell. I purchased the 100 ohm resistor and mini cooling fan at Radio Shack. Tested the old fan with 12V DC and the 100 ohm resistor. Verified voltage present at the solder points on the fan motor.Fan not working. Cut wires and plug off of old fan and plugged into board to check for voltage out to fan. Plugged the charger in without connecting it to the battery. Got the snap sound at the line cord plug. Charging voltage at the RCA plug 58.2V DC, fan circuit not activated.Plugged in the charging cord to the battery, read 18.7V DC with my Beckman Industrial DM10 meter at the fan wires ( no fan ). Installed the Radio Shack fan and it works so far. Noisier than the original. 7.7 CFM feels like more airflow, 6500 RPM , noise rated @ 29Db Another good sign, the charger is now cycling in balance mode.

 

[dnmun]

i see them in ebay stores a lot too. sometimes they screech so bad you wanna unplug them, but then the things seems to whir after that. i put oil in the end. this is the first one i have heard died. open was good info though.