Lithium Battery Repack / Repair NZ

Lithium Battery Repair or Repack NZ

Getting your lithium battery repacked or repaired, reconditioned or even improved in NZ can be challenging, to make your life easy we have created a interactive map, select your region to see a page of known repairers in that region. 

Do you offer lithium battery repair services and want to be on this map? We’ll list your business for free! Let us know at [email protected].

Lithium Battery Repair / Repack / Recondition

Typically, battery repairs involve removing and testing each cell, checking that the BMS is functioning correctly and putting it back together. It can be categorised in three ways:-

  1.  All cells are replaced with like-for-like replacements
  2. All cells are upgraded typically for increased capacity
  3. For larger battery packs often changing all the cells is cost prohibitive, instead an individual ‘dead’ cell is located and replaced.
Benefits of battery repacking

We all have batteries we rely on in our lives, power tool batteries like this DeWALT, are a staple on building sites all over NZ. A typical power tool battery has 18650 or 21700 cells in them; over time or from use (charging and discharging), they degrade, meaning they won’t last as long or hold their charge.

Our pictured DeWALT example would have 10 cells grouped in five sets of two pairs in parallel, then all five pairs wired in series.

Two cells in parallel provide an increase in capacity, so these cells would be 2500mAh combined to create 5000mAh ‘twin cells’.   

All five ‘twin cells’ are then wired in series; wiring in series increases the voltage, this would give us a voltage range between 21V, fully charged and 17V when discharged.

Changing the cells can provide a significant increase in capacity, it would be pretty easy to create a battery with twice the capacity of this one. Plus, it would most likely be cheaper than replacing it, saving a lot of plastic from landfill.

Can you fix a lithium battery that won’t charge?

Sure, you can fix it. Step one would be to check the charger, The easiest way is to confirm if your charger can charge a different battery.

If the charger works, you can contact your local repair specialist and  get them to replace the cells.

Remember always use the charger supplied with your battery!

Can you bring a lithium battery back to life?

Yes, but depending on the size, you might be looking for a dead cell on a vehicle or on smaller ones it’s often a cell wired in series that has failed so the battery pack no longer makes the required voltage to drive what it should.

Step one would be to check the BMS or battery management system is working, and if it is, replace all cells or use a multimeter to find the dead one and replace that.

Why you shouldn’t solder a lithium battery

A lot of people have a go at battery repair, after all the battery is useless so taking it apart isn’t going to break it any more right? So you have it apart and you have possibly noticed those metal strips connecting the cells together with the spots on them. Well those spots are welds, cells should be welded, not soldered. Why? We hear you ask.

Lithium cells degrade when they get hot; the fastest way from usable to unusable is to get them hot, and as soldering involves a lot of heat, you are degrading the cells before you even start, so either buy a welder or let the professionals repack your battery. Plus, an errant blob of solder could bridge the positive and negative terminals; best case, you’ve ruined your cells; worse case, you could have a very difficult-to-contain the fire.

In short, get the right tools and do the job properly or leave to the professionals.