Battery Pack Rebuilds: BionX and Others

The rumors are true!  I do rebuild old BionX battery packs, and several other varieties as well!

If you have such a pack, and live in the United States or Canada, I can rebuild your battery pack.

You might need your pack rebuilt because it sat for a year or two without being used.  In this case, the batteries are totally dead and cannot be safely recharged.

You also might need your pack rebuilt because you use it regularly, and it's gotten weak with age.  Range will drop.  I can also fix this!

BionX 36v 9.6Ah Downtube Packs: Rebuilt to 13.5Ah

These are the most common packs I rebuild.  If you're interested in what's in them, check here.  To see what I do for a rebuild, go here.  And if you want yours rebuilt, there's a contact form on the right side - get in touch with me!


My rebuilds replace the stock (and likely very worn out) 1600mAh Sony US18650V cells with brand new 2250mAh Sony US18650V3 cells.  This takes the pack from the stock 9.6Ah to 13.5Ah (a ~35% increase in capacity).

If your pack is of this style, it will be a 36v pack, 9.6Ah, and likely say "LiMn" somewhere on it.  I rebuild these regularly, and have rebuilt packs in stock to swap in.

Price is $450 plus return shipping (I ship ground, properly packaged and labeled as lithium batteries).

BionX "Brick" (36v/13.5Ah battery) for DIY Replacement


If you're comfortable with a soldering iron and working with potentially high amperage systems, I also sell just the battery brick.  This is the same thing I would install, but shipped to you for installation.  You can do the install in an hour, avoiding needing to be without your pack for a week or two (ground shipping can be slow).

You open up your pack, remove the old brick, and solder the new one in.  I ship it "ready to install" - compete with folded tabs and solder puddles.  You'll need a decent soldering iron.

There are two different cell layouts, and I need to know which one you have to ship you the correct pack.  One has two wires feeding into the pack, one has 12 wires.



This is not something you should do if you don't already have a lot of experience with soldering irons and wiring projects - it is not a beginner project.

This is $425 plus ground shipping.

BionX 26v 9.6Ah Downtube Packs: Rebuilt to 18Ah



The BionX 26v 9.6Ah pack is an interesting pack.  It's the same capacity as the 36v packs, but a lower voltage - so fewer cells groups in series.  It turns out, the case will fit a large pack.  So I offer a rebuild to 18Ah that uses 54 cells instead of the original 42.  Combined with the larger per-cell capacity, you get a pack that's almost double the original capacity.

Price is $450 plus return ground shipping (hazmat).

Trek Valencia Ride+ Battery: Rebuild to 9Ah


If you have a Trek Valencia Ride+, I can rebuild these batteries as well.

The stock battery is a 40v, 6.4Ah battery.  I rebuild it to a 40v, 9Ah battery - so a 35% improvement in capacity.

The cost on this is $600, and I will warn you that the pack will almost certainly show some marks from being opened.  The pack is literally glued together, and it takes serious amounts of force to separate it.  I try to only mark the underside, but this is not always possible.

Other Packs

I may be able to rebuild other battery packs.  If it's 18650 based, I probably can.  If it's pouch cell based, I likely cannot.

Get in touch with me and let me know what you have.  I do offer a discount for the first instance of a new pack type, though it generally takes longer on the first instance of a pack.

The Process

The process of getting your pack rebuilt is simple, assuming you live in the United States or Canada.  I can ship batteries overseas, but be aware that it is painfully expensive - $350 is typical for air mail of dangerous goods.  You really should find a local rebuilder.

Contact me with the form to the right.  Let me know what you have, and where you're located.

Once we work out details, ship me your pack.  I prefer you to remove the battery from it before shipping, though there are options if you cannot do this.

I try to keep some of the common packs in stock for two day turnaround - this is likely, but not guaranteed, on the 36v 9.6Ah downtube packs.  For other packs, I have to build the pack from cells and this generally requires around a week.  I require full payment (I accept PayPal and Bitcoin) before return shipping, and I will also accept personal checks sent with the battery pack.

Return shipping generally runs around $70, depending on where you are located.  The upgraded capacity requires dangerous goods packaging and shipping, which is rather expensive.

Bike Shops/BionX Dealers

If you are an owner or employee of a bike shop that deals with BionX systems regularly (I know there are a few such shops out there because I talk to them) and are interested in offering a pack swap service, please get in touch with me.  We can arrange something where you remove the batteries from a pack and ship it my way, or where I ship you replacement packs for you to install.  It requires soldering and some attention to not shorting out the pack while you deal with it, but it would allow you to do the repairs same-day or next-day for customers.  There are two pack configurations in common use for the 36v systems, and I can send you one of each to have onsite.

Warranty and Such

There is none.  This is a rebuild of a proprietary system that is not designed to be worked on, I do not have manuals for, and I only have a limited amount of information on.  If you want a warranty, buy a new system (though I will buy old systems with bad batteries - contact form is over on the right).

I will do everything I can to provide you with a working pack, but there are certain things I cannot fix - I cannot fix a bad BMS (battery management system) board, and spares are nearly impossible to come by.

The packs are generally at least 7-8 years old, and things do fail.  I test packs before I return them to a basic standard of functionality, and I will test a BMS before I rebuild a pack (especially if the pack is not powering on due to dead batteries), but I'm so far outside the realm of supported things to do with BionX systems that I cannot offer any solid guarantees.

However, if something goes wrong, get in touch with me and I'll see what I can do.

Again, the contact form is over there! ->

Customer Reviews

"I bought a Bionx eBike in 2009 and by the summer of 2016, the battery was kaput.  When I bought the system in 2009 the dealers had assured me - the batteries will only get cheaper as lithium ion batteries become more common (at that time a new battery was $500).  Fast forward to 2016 when I looked at a new Bionx battery I was looking at a hefty $1300 for a new CanBus battery from Bionx.  Ouch!   After researching the issue online I found Syonyk's helpful blog.  After briefly contemplating rebuilding the battery myself I decided to avail myself to his rebuild services.  We had a few initial exchanges of emails and I shipped my dead battery to him.  Fast forward 10 days I found myself with a new rebuilt battery at a significant discount to purchasing a new battery!  I'm highly satisfied and highly recommend his battery rebuild services!  So great to have my Bionx bike back with extended range!  THANK YOU SYONYK!  Highly recommended."  - T. Chen - Foster City, CA

“Russ did a superb job on rebuilding the (difficult to service) Valencia battery pack for my five-year-old Trek this summer.  I sent him the old pack (UPS had the best deal for me), which he advised me to disassemble in order to remove the cells. That saves shipping cost from having to send the old pack out as 'hazardous material.'   Russ  worked on the pack for a week or so, and sent it back literally better than new: the new pack has more range than the original one did, due to the improved cells he uses.  Best of all, he’s great to work with, and kept in close and friendly communication every step of the way.   So let’s call it five stars, and most certainly highly recommended."  — Michael M., Farmington, Michigan