BT-E6010

Typical problems

• Corrosion
  • Nothing to do, goes to recycling.
• Deep discharge
  • Sometimes it survives being woken from deep discharge. Usually not.
• Bad BMS
  • We cannot buy new BMS, but it is possible to swap BMS between identical batteries.
• Blown smart fuse on BMS
• Broken housing

Error codes

Taking it apart

• 8x T10 security screws - you cannot use a machine for them, only normal screwdriver
• 2x PH1 screws near the handle
• Then the top pops off easy

If you need to take the pack out:

• Turn it upside down to slide out the pack from the housing
  • A small blue gummy thing will fall out - don't lose it!!
• You need to push the connector out of the housing with some flat tool

Blown smart fuse on BMS

If the battery seems to be charging, but shows an error message after 15-20 seconds, it is almost certainly the smart fuse which is the problem.

The smart fuse in the rectangular surface mounted component with the 30A K10 A marking on it. It is near the positive end of the battery.

Replacing the fuse while the BMS is attached to the battery is very dangerous. It shall be done with extreme care, masking all surfaces possible, and wearing protective gear.

To verify that it is indeed blown

• If the BMS is removed: set up a multimeter for continuity testing, and test for continuity between the two sides of the fuse. If there is no continuity, the fuse is blown, and must be replaced.
• If the BMS is in the battery: set up a multimeter for current measurement, 10A. Hold the probes on the two sides of the fuse, and ask someone to plug in the charger. It shall charge, and you shall measure the charging current - thereby verifying that only the blown fuse stops the battery from working.

Use the hot air gun to carefully remove the fuse, without melting anything else. Use the medium nozzle, air control on 5.5 and heat control on middle setting.

Dremel way

Now use the Dremel with the soft and wide grinding wheel to remove the white solder mask and expose the copper surface below.

Now use the soldering iron to deposit two large tin blobs on the exposed copper, and finally install a 30A mini fuse into it, as shown on the photo.

The battery should now work fine.

The tape way

Actually, it is possible to do a faster and better job without the Dremel. The trick is to position the fuse just right, and fix it in place with some tape.

Hold the hot iron in a way that it touches the leg of the fuse and the pad, and add solder to join them.  You can help align the fuse with one hand once you have enough tin.

Be extreme careful not to join one of the big pads to the small pad of the smart fuse! It will burn the whole battery!!

Once one fuse leg is soldered, the other will be easy.

Replacing the smart fuse with original part

Now we have original replacement fuses. However, before installing, you must check if the new fuse is not going to blow instantly due to the trigger being on battery negative. Basically if you measure the battery voltage between the fuse terminals and the third leg, do not put in a new smart fuse.

The speculation is that it might be a latching solutions that once triggers stays on... How can that be solved?

We must check on more batteries. So far I only tried to install a smart fuse once, and it blew immediately because the trigger was on.

Putting it back together

• Unplug the cable from the indicator board
• Wiggle the cable out of the bracket on the pack
  • There will be some glue, comes off easy
• Put the pack in the housing
  • Carefully push the charge/discharge connector in simultaneously
  • Pay attention to the four wires of the connector!!
• Place in the small blue gummy thing
• Slide in the indicator board
• Plug in the indicator board
• Slide the cable back into the bracket
• Test that the button works well!