E-bike battery development

[Wowbagger]

Some years ago Jan and I bought a Circe Helios tandem fitted with the Shimano Steps motor. We haven't used it a great deal, but one thing I've always thought about is the possibility of buying a solo e-bike, and I always thought it would be sensible to buy one with an identical motor so that if I were on a ride long enough to require extra electrons (>40 miles or so), I could stick a second battery in the luggage. However, having a look around different bikes currently on the market, I can't find anything using what appears to be a similar battery to ours. In fact, the trend seems to be to embed the batteries within the down-tube, "for aesthetic reasons".

Does anyone know if there are any down-tube embedded batteries that can be taken off the bike to be charged? It seems to me to be a pretty bad idea if not, as a decent bike frame is very likely to outlast the battery cells, and it also means that if (for example) you are on a tour involving B & B, you need to take the entire bike to the plug socket rather than an easily-portable removable battery.

It's not surprising that the technology is rapidly developing, and those of us who were early adopters might find our kit obsolete, but built-in obsolescence like this is, to me, anathema to the philosophy of cycling.

[grams]

To my knowledge integrated batteries are always replaceable, and many are quick or quick-ish release. A lot of them lift out the top or bottom of the downtube. If you squint at the photos the seam should be visible.

There’s usually a charging port on the battery for off-bike charging.

[Kim]

One of the things that Falco got right was their "here's our range of battery packs, but really all you need to do is present 36-52 voles to the battery connector, and btw here's the part number for the correct plug" approach to batteries.

Fairly sure that STEPS batteries are alive and well in bottle-cage and rear rack mount flavours.  The recumbent makers all seem to be using them, with various custom mounting brackets.  But the trend for DF e-bikes does seem to be integrating them in the down-tube.

I notice that Bosch 'PowerTube' seems to be a thing.  Looks like a range of standard removable downtube-mounted battery used by various OEMs.  Further googling suggests that the Shimano equivalent works in a similar way.

Absolutely agree that a battery that can be removed easily for charging is essential (with a possible exception for folding bikes).  Otherwise we'd need e-bike charging infrastructure.

[T42]

I've been looking into these things with a view to not blowing a gasket in the next col. What I've gathered:

AIUI, Fazua downtube batteries (as fitted by Trek) can be changed by the user, but Mahle eBikemotion "integrated" batteries need quite a hefty workshop intervention if not return to the factory.  Mahle do provide a back-up battery that takes up your rear bottle cage.

Fazua-fitted bikes tend to be a bit heavier, but a nice feature is that, when the motor is off, both it and the battery retract from the bottom-bracket cog so that there's no load to turn. You can also ride the bike without either.

Both of those provide 250 Wh which, if you don't switch on until your heart rate is around 90% max, could take you over a not-too-lumpy 200k.  Mahle also provide an app that can pick up your ANT+ -mediated heart rate and turn the motor on or off accordingly.  The Mahle charging port is on top of the bottom bracket, and they claim that it's waterproof. Dunno how it would react to a dowsing in sugary drink.

Another bunch, BH, using different tech, provide 540(-ish) Wh, that they say is good for "up to" 165 km of continuous power.

[grams]

In terms of your actual problem, there are still loads of non-integrated ebikes out there and you can surely find a battery the same as your old bike and swap it on to your new bike, or vice versa. As Kim says, it shouldn’t care what shape battery its voles are coming from.