LiFePO4 36V/10AH not charging correctly?

[luismarques]

Hello all,

I got a kit, which I'm still finishing assembling, but it is now complete enough for a small ride. It seems to work OK.
But I'm not so sure about the LiFePO4 battery. When I charged it some of the LEDs never lit up. I recorded the whole process. It was something like:

- No individual LEDs ON
- After a short while several individual LEDs got on
- After a long while 1 or 2 more LEDs got on
- After another long while the fan stopped
- A short after that while the LEDs started turning off one by one and the charged LED went on.

Still, about 5 LEDs (I have to confirm the number) never lit during the entire process.
From the output I measured 38.9V after charging. From the charging connection I measure very different voltages from the several pins. I tried opening the battery, but it seems the individual cells are all wrapped together inside so I couldn't measure individual voltages.

Does this mean the battery has a bad cell? Perhaps I need to discharge the battery more for all the cells to charge and their LEDs to light up?
Is it possible to measure the individual cells from the charging outlet pins?

Thanks for your advice and opinions.

Luís

[Spacelander 1946]

From my experience with a similar battery the fully charged seems only slightly low, mine charges up around 41.5V (so you may have a dud cell?) I don't have individual leds on mine only a red for charging an a green for fully charged, takes about 3 hrs to fully charge. I get about  30kms on a full charge and cruise @ 29Km p/h (very few hills where I live) Also make sure your charger is on a clean hard level surface with plenty of cool air for the fan.....not left on the bed etc or the unit will overheat a burn out components (like I did!) some of these cheap chargers that come from China with your battery are hopless, best to buy a decent metal case one, though would cost about $200 or more!.........Hope this helps a bit.........Cheers & good luck.

[Joey D]

space lander I'm getting an arc when I plug the charger in the wall. Can you help?

[ahend]

You can check individual cell voltages from the charger connector. Check out reply #42 on this thread for the pinout diagram of the Golden Motor 36V 10Ah LiFePo4 pack.

[Spacelander 1946]

space lander I'm getting an arc when I plug the charger in the wall. Can you help?

Attention JoeyD.......You will get an arc/spark/cracking noise when you plug your battery connection into the main bike/motor connection only!...BUT if your charger is sparking at the wall socket this can be very dangerous!....best to go to a TV tech man for repairs/advice on your charger ALSO You may have been sent the wrong CHARGER for your country, input voltage eg 110V or 240V? check that as well! OR if all above is OK get an electrician to check your wall sockets etc. Please don't fry yourself, OK......Cheers & good luck.

[luismarques]

I have contacted Philip Yao, asking if he would send a replacement battery.
It has been almost a week now, and three emails later still no reply.

[biohazardman]

I have contacted Philip Yao, asking if he would send a replacement battery.
It has been almost a week now, and three emails later still no reply.

A week is nothing there are allot of bad batteries floating around and it seems to take a month or better for some to get replacements.  Looks like he got involved with the wrong company to supply his Lifepo4 batteries.