I purchased a 48v 20ah lifepo4 pack from vpower on eBay. After waiting about a month I received the battery pack and 2 amp charger. As soon as I connected the charger it blew, I think it was because it was an SLA charger they sent me. I contacted vpower and they sent me another charger a 48v 5amp lifepo4 charger for $30.00 and received it in about 2 weeks and began using it. Today I got home and went to charge the battery pack and noticed the charger was totally off, I thought it was unplugged but it wasn’t. I opened the charger and noticed a burn and crack mark on what I think is a ceramic capacitor. This question goes out to anyone that can help me fix it, I have included some pictures so who ever responds can get familiar with which product I am writing about. I need to find the value or specs of the black ceramic capacitor, see below for pictures. Sorry about the quality if you need better pictures I should have a better camera later tonight.
This is the charger as seen on eBay http://i20.ebayimg.com/08/i/001/55/f7/501d_12.JPG
This is what it looks like http://www.infotroop.com/chargercover.jpg
This is what the charger looks like inside http://www.infotroop.com/chargerinsides.jpg
And this is the black ceramic capacitor I need to find the value of; it’s located on the wall plug side behind the fuse http://www.infotroop.com/xblow-resister-next-to-fuse.jpg and http://www.infotroop.com/blow-resister-next-to-fuse-.jpg
I finally got in touch with vpower last night and he explained the thermistor is an NTC thermistor 5D-13. Now the problem i have is finding one, any ideas????
A general electric,(GE) type# CL-40 inrush current limiter should work. It will handle up to 6 Amperes of AC input current, and has a 5 ohm cold resistance. This part is available from NEWARK electronics, their stock number is: 81F3388, price is about $2.50 each. (Telephone NEWARK at: 1-800-463-9275)---Bob Curry
Robert M. Curry
Did the FUSE blow? If it did, there may be other problems with your charger! If other parts are bad, the new NTC resistor will also fail. Be sure not to short or overload the charger.-Bob Curry
Robert M. Curry
No the fuse has not blown but i have gone through two NTC thermistor 5D-13. They slowly burn as the charger is used. I ordered 5 spare NTC thermistor 5D-13 from digikey http://search.digikey.com/scripts/DkSearch/dksus.dll?lang=en&site=US&WT.z_homepage_link=hp_go_button&KeyWords=317-1195-ND&x=21&y=18 so i can charge my 48v 20ah LifePo4 battery pack.
The device they used is apparently too small for the job, so try the one I suggested, unless you like wasting time and money repeating the failure!-Bob Curry
Robert M. Curry
Hope you fixed it okay. Just need to know if mine is actually working. The light goes from orange to green as the pack becomes charged, but the fan carries on going - does this happen with yours? I presume it has stopped trying to charge. I do not want to overcharge, as it has been quite a hassle and expense to get these batteries.
I have owned 2 of these chargers. The red light is just a power indicater. The other light should show yellow while charging. The light turns from yellow to green when its done. Yes the fan always runs as long as the charger is plugged in. Its rather silly but I expect such from Chinese stuffs.
My first charger lasted a year. I started using it during the winter here in NJ. It worked fine from what I could tell. When the summer came and the storage area was around 85 degrees the charger started to give off a distinct hot electronic smell. It smelled like an old dusty amp being plugged in after 10 years of dusty storage. The charger soon stopped working. The thermistor in question totaly destroyed itself. There wasnt even any black coating left. Just the metal disc and 2 wires.
My second charger Is less then 3 monthes old. I started using it in the warm season. This time I charged my batteries in a room with AC. Around 71F. When It finaly went a few days ago one of the leads literaly just melted off of the device.
Am I supprised my second charger went this way? Not at all... This is super common when using Chinese electronics. The US alternative is well over 150$ last I checked if you can even find one..
On another note V-power lifpo packs have the best bms I have ever seen. Single cell monitoring and the works. I have had the pleasure of shorting my pack out 2 times heh. Works perfectly.
I ride my E-bike(48v/1000w) with a 48v/20ah vpower pack every day. I take it to work and just about every place I go under 20 miles round trip so my info is from a heavy user.
My pack seems to be pretty good so far I've covered 1200 miles with not a hint of fade. I love the way the voltage stays pretty steady and you get as much power from the first moment to the last. The pack fully charged, however, is too much for my bike and knocks out the motor management for about 5 minutes after a full charge. I think I'll have to get some step down voltage transformer between the mains and the charger (????) or something to get it to stop charging earlier (Don't know if it works).
Bit worried about the charger blowing as I really would be up the creek without the bike. Why don't they teach fixing cheap electronic equipment in schools? It would save so much sweat.
This is a really interesting post. I just purchased a KP-668LF power supply and have noticed that it starts having an electronic smell and then after about 5 mins I start hearing a clicking noise. I also noticed the thermistor is burning hot. Did anyone experience a clicking noise when there thermistor was bad?