As anyone who has seen a Bionx frame-mounted battery knows, it sticks out like a sore thumb. This is good for sparking conversations, but not so good for leaving the bike outside for any length of time -- I just can't shake the feeling that that big "Bionx!" logo looks really tempting to thieves, even if they don't know what it is. Plus the font doesn't look very high-tech, and is more reminiscent of something you'd see in an old magazine ad from the 1980s.

I looked for bags that might hide the battery, but I wasn't having much luck. I was about to head to the store for some spray paint and rags when I stumbled upon an easier solution: duct tape! I know, I know, it sounds horribly low budget, and it is, but if you use colors that blend well with your frame, it actually works out really well. I chose two colors - "olive drab" (which is actually much darker than it looked online), and a "digital camo" style for flair. A bit of trimming with a utility knife, and I'm very happy with how it turned out.

Before and after pics attached...

Very nice, much harder to tell what's there. I have the rack mounted battery so it's much more stealthy, particularly when surrounded by panniers, but the balance with a heavy battery that high is tough. Not when moving of course, just when parked. I never leave it outside though.

I was contemplating the idea of getting one of these:
https://www.ebike-easy.com/products/B...PL-250-HT.html

Looks quite decent:
https://shop.leichter-fahren.de/image...mages/97_1.jpg

I would still not leave the bike with the battery unattended outside. You can force the battery out with a screwdriver in less than 5 seconds.

Those two covers look very neat, but expensive! The second cover looks really sleek (except for the raised "Bionx" lettering, which gives it away).

You're saying a screwdriver will defeat the lock that connects the battery to the mount? Or do you mean a thief putting a screwdriver UNDER the mount can easily pry it from the frame?

I peeled off the Bionx decals to leave a big white battery box. I bought that Topek bag too, only to discover anything inside that black bag would roast like a furnace. Same goes with the dark color camo you put on the battery. It is going to get hot!

While you're at it, you might tape over the recharge port, it is not weather proof.

I was a little concerned about the heat aspect but my Bionx dealer told me it should be fine... he was also okay with my painting it. He told me neither would void the warranty. That's a good idea about taping over the recharge port, but I'd have to replace the tape every time I recharge it.

What happened when you put the battery in the Topeak bag? Other than getting hot, were there any negative effects?

Re: Battery getting hot:
I am treating my battery like a baby. If you read about batteries in general and lithium batteries in particular you will find that: they should never get too hot, they should never get too cold, they should never stay discharged, they should never be stored in a cold or humid place. The battery should always be charged and the optimal temperature is about 20 Celsius. I learned this the hard way. Not paying attention to these details or being negligent will cost you $$ because your battery will suffer and you'll find out pretty soon because it will no longer hold charge, loose capacity, etc.
Also, I learned the hard way that a charger can lie and tell you the battery is charged (charging) while it's not. If you suspect this happens take action right away as running with a battery half discharged will ruin it. A voltmeter for checking the battery voltage periodically or whenever you see some strange behavior is the best thing.

Re: Battery being removed with a screwdriver
I haven't tried that myself and I don't recall the details but I believe both options are possible - forcing the battery off the bracket and forcing the bracket off the frame. I've heard that from two people and I believe it makes sense. Bike thieves can remove locks and chains that are pretty heavy, I don't see two rivnuts in an aluminum frame or a plastic lock being a problem for them.

I made a dust cap out stuff I had in box of junk.

I didn't get the Topeak bag for the battery. Rather it was for a small pot, stove, fuel cartridge, a cup, tea, and some slices of frozen pizza left over from the night before. I bought a white gym bag and use the Topeak Basket I've always had.

I had the exact same concerns as you. I went with the spray paint route after peeling the decal off. It was very easy and the results looked very clean.

" they should never stay discharged " ???
Wrong!
Lithium based cells hate to be kept at high charge voltage.
Unless BIONX ones are not Lithium based

This isn't correct. You can run with a battery half discharged. This is what happens midway in a long ride! I'm not familiar enough with the Bionx system, however I would think that the BMS would protect the battery from being damaged. You would, of course have reduced range and probably speed, however it shouldn't ruin it.

As for checking the voltage, I'm a big advocate of the Cycle Analyst from ebikes.ca. It allows you to keep close tabs of your battery at all times with a wealth of information and is worth it's weight in gold. IMHO.

Duct tape! Gag me with a spoon!'
Since I have a Brooks saddle and grips, I covered the BionX sticker with matching brown leather attached with Scotch 'permanent' mount double sided tape. Originally planned to cover the entire battery with a bespoke leather case, but this was a lot simpler and looks like a million bucks! I don't leave the bike for long with the battery installed, and wouldn't, even if it was covered in duct tape. A beautiful bike is a source of pleasure to me and worth the security risk. I use a Kryptonite NYC 'U' lock combined with an Abus bar chain model.
Mike

Actually, right! Proper long term storage should be 50% charge.

Actually this is correct, in that one should not use a battery that is not brought up to a full charge before being disconnected from the charger. And the BionX panel is more than sufficient for battery monitoring in combination with the LED indicators on the battery.