Bosch has been a lead designer and manufacturer of electric bike drive systems and batteries globally since 2010 according to their official website. I began seeing them arrive in the United States around 2012 with integration on Haibike electric mountain bike models. Since then, other companies like IZIP, Riese & Müller, Bulls, Felt, Trek, and many others have chosen to use Bosch. This is a brand that is known for providing excellent warranty support, durable designs that are easy to service, and products that hold up over the long term.
Around 2015, the original Powerpack 400 battery was joined by a higher capacity Powerpack 500, which offered ~25% more range but only weighed 0.3 lbs more and fit into the exact same form factor while remaining backwards compatible with the same mounting interface (rack or downtube). During this period, we saw the rack-mounted Powerpack being offered in both 400 and 500 watt hour sizes as well, although this design tends to weigh just a bit more. Eventually, in early 2018, the Bosch Powertube began showing up in the US and the mountain bike companies Haibike and Bulls were quick to adopt it. In the video comparison below, I show all three battery designs (rack, downtube, in-tube) and talk about why one battery design might be preferable to another based on the type of riding being done. Weight distribution is a key factor, the ability to easily replace or rent a pack, and the desire to be stealthy all come into play.
Below, I will list out some of the measurement differences between the different battery types that I have had access to. These measurements were made with my own personal scale. This data may not perfectly apply to all integrations (especially the Powertube which relies on the bike designer to create a covering which can weigh more or less depending on thickness and material). I want to highlight that each of these batteries use the exact same charging interface and that Bosch offers two charger types. The standard charger weighs ~1.7 lbs and offers 4 Amp output vs. the smaller compact charger which weighs ~1.1 lb and offers 2 Amps for slower charging.
- Downtube Powerpack 400 weight: ~5.4 lbs (2.45 kg)
- Rear Rack Powerpack 400 weight: ~5.7 lbs (2.59 kg)
- Downtube Powerpack 500 weight: ~5.8 lbs (2.63 kg)
- Rear Rack Powerpack 500 weight: ~6.0 lbs (2.72 kg)
- Powertube 500 naked weight: ~6.15 lbs (2.79 kg)
- Powertube 500 with Bulls designed skid-plate weight: ~7.3 lbs (3.31 kg)
Below, I will write out some of the pros and cons of each battery design based on my own experiences and observations. I will offer some tips on when one pack might be optimal and I invite you to share your own feedback in the comments section below which I may incorporate over time to add color to this guide :)
- In my experience, the rear-rack mounted Powerpack battery is optimal for wave (deep step-thru) style bicycle frames that aim to lower stand over height by removing the top tube and eliminating mid-frame clutter. The downside here is that battery weight is positioned high and towards the back of the bike which makes it less stable and can contribute to frame flex and speed wobble if even more weight is added to the rear rack in the form of a trunk bag or panniers and if the frame isn’t stiff enough. Speed wobble happens when the front wheel doesn’t have as much weight on it and wants to naturally turn side to side to achieve balance.
- In my experience, the mid-frame mounted Powerpack battery is optimal when weight distribution is important (such as mountain biking or sporty city riding) but convenience, lower cost, and portability are also factors. The Powerpack battery has been produced since 2012 and is widely available, both the 400 and 500 fit into the same mount interface (possibly also the European 300 Powerpack) and therefore, you can easily rent or borrow one of these batteries for use on your own electric bike vs. trying to ship one. Since shipping of high capacity Lithium-ion batteries is difficult (even trying to fly with them on commercial aircraft is limited) some people opt to sell their battery in one country and buy a new one upon arrival. This is not as easy to do with the Powertube which requires a special plate interface that is unique to each bicycle manufacturer
- In my experience, the completely hidden in-frame mounted Powerpack battery is optimal when aesthetics and balance are the major factors. This battery is not as convenient to charge or remove as either of the two Powerpack designs but it is very well protected, positions weight even lower than most Powerpack designs, and allows the frame color and designs to be uninterrupted… however, it may not fit on smaller frames with shorter downtubes. It also weighs a bit more and may be difficult to replace and thus limiting if you move and want to ship your bike somewhere without the battery. Buying a new battery upon arrival would mean re-attaching to the proprietary frame plate that came with the original pack. I like that the new Powertube design tips out at the top of the downtube and that there’s a small button to fully release it vs. just relying on the key locking core. It felt safer to unlock and remove than some competing offerings, but it can still be heavy and tricky to grab compared to the Powerpack designs which weigh less and have handles molded into their casings
For those interested in learning about the earlier Bosch Classic and Classic+ battery and motor systems, check out the official Bosch website here. Those earliest ebike batteries were not made available in the USA and I have only ridden with them once on an imported Haibike mode at the old Currie Technologies headquarters location in Simi Valley, CA. The Classic battery offered up to 288 watt hours of capacity and then moved to 300 wh and 400 wh with the Classic+. The Drive Unit 25 and 42 during this period were rated at 250 watts and 350 watts respectively, and produced up to 50 Newton meters of torque. By comparison, the Performance Line Cruise motor offers up to 63 Nm of torque and the 2018 Active Line offers up to 45 Nm.