Bosch range extender development
Posted by thepeyoteadventure@reddit | ebikes | View on Reddit | 19 comments
I've been developing a range extender for BES2 Non-smart Bosch bikes, as there's no OEM solution.
You could add a rack carrier version but that messes with CG.
I'm using an original powertube 400 or 500 horizontal version, connector with cable goes to the motor, parallel with the other battery wires and canbus wires. Fully integrates with the Bosch system, thermal protection, charging sharing, range estimates. Way safer than a lot of range extenders that require drilling in the battery and conncting straight to cellpacks without fuses.
I'm wondering how much people are willing to pay for this? It could be sold as a kit without the battery, enabling easy shipping over the world, as long as you have the powertube available locally.
This system can also reduce wear on both batteries, as the load is shared between the 2. Especially with chipped or speedmodded/Torquemodded bikes this can be advisable.
thishasntbeeneasy@reddit
I don't understand power sharing between two batteries. I'd want to deplete the extender first, leave that back at the car on the next pass, and not carry the extra weight.
thepeyoteadventure@reddit (OP)
Then you can use a simple switch to swap 1 wire around. I've already thought of that and it can be implemented for those that need it. But you put more wear on each battery that way, as they see full power all the time.
mmeiser@reddit
I have noticed when running dual battery I have effectively doubled the kife of the batteries. My actual useage statistics say I may get 70,000 miles out of my two dual battery systems. So far I have 23,000 on them. Since the batteries get swapped between the systems I have to treat then as a single unit and average it. It averages to about 17,000 miles per battery. We shall see if they kast that long. No signs if cell failure yet.
thepeyoteadventure@reddit (OP)
Exactly, I've also noticed dual batteries lasting over 50.000km, meaning each battery does 25.000. Normally I see my customers come in for new batteries after 15-20k.
mmeiser@reddit
To be clear I am talking miles. But generally that tracks. Dual battery, 50000km s 30,000ish miles or about 15,000 miles a battery.
exile_10@reddit
That's going to be 3 to 4x the weight rating for the bottle mounts isn't it? Aren't most 1 to 1.5kg?
I could see that ripping a carbon frame to shreds very quickly.
thepeyoteadventure@reddit (OP)
Yeah not for carbon frames this one. Only Alu, Ti or steel. Or reinforced carbon (some bikes do have this around the bottle cage area, Alu plate). Powertube 500 weighs 3kg. It is possible to add more threaded rivets, or bolt straight through and access on the inside of the frame to put bigger washers and nuts.
Many non Bosch bikes use a bottle cage mount battery of similar weight, though above 4kg there starts being trouble.
Snarkosaurus99@reddit
You’ve been developing or have developed and are doing some subtle spamming?
thepeyoteadventure@reddit (OP)
I am still developing, no product available for purchase yet.
alvl5abra@reddit
Bosch has already a range extender (powermore 250) or you can always just use 2 of the same powerpacks in parallel.
thepeyoteadventure@reddit (OP)
Bosch has a bes3 smart range extender. Not a BES2 one. This setup uses a Bosch original Powertube with custom mounting. The powertube already is dual batt compatible and protected. Believe me, the Bosch system wouldn't allow random stuff added into the battery output.
alvl5abra@reddit
Oh the BES2 motors, aren't those the second gen motors? I dont want to be rude, but that system is 6years old and while I still enjoy my old cx motor, most riders have upgraded.
Also does this work with old bikes that use powerpack400's or only with bikes that use a powertube? Where would you put the extra battery?
thepeyoteadventure@reddit (OP)
GEN4 motors are still BES2. BES2 still is being made and used on bikes. I get plenty of bike shops for mods and warranty repairs that Bosch doesn't cover, still getting plenty of new bikes with BES2
mmeiser@reddit
But bosch does support dual battery. I have two bosch set up dual battery so I can interswap batteries. You just need the y adapter and some mounting hardware. But they do restrict sales. :(
thepeyoteadventure@reddit (OP)
There's no mounting hardware except for the frame or rack battery. The frame version requires a rectangle mounting post to be welded on the frame. The rack add high center of gravity, doesnt ride well.
mmeiser@reddit
There is no external mount for a powertube. The external powerpacks do have mounting hardware. A lockable mount for one end and for olthe other a mount that contains a power port. The lock end uses two bold holes about an inch apart. The lower has soke sorr of funkymout about 2.5-3 inches apart that the actual mount then bolts onto.
I have always wondered if you could use thepower tube internal frame mount externally but if I was going to do it I would hide the extra tube and wires in a frame bag under the top tube. Am bikeoacker and commuter. But yours does look clean and professional.
thepeyoteadventure@reddit (OP)
The powertube internal mounts are not sturdy enough for external use, I've tried. They need multiple support points.
mmeiser@reddit
To be clear both my systems are the older versions orior to the new smart system. On the one frame that didn't have mounts I simply drilled some holes in the aluminum and put in some rivnuts like are used for water bottle cages. I am using the 500 power packs because they were the biggest thing available at the time. Mostly I just use it for commuting but I have taken to doing some touring / bikeoacking. I find I can push an upper range of 70 miles with 7000 vertical feet on two batteries. Using it mostly for climbing. Since I have a spare set from the second bike this gives me an upper limit if about 140 miles. My record is 145 miles with 15000 vert on day one and after a night to recharge 122 miles with 12,000 vertical feet on day two. I think I could push it further if i was not in a but if a rush but I am always in a rush. This little overnighter took about 34 hours. I was delayed at least a couple hours because one of my two chargers was not a 4amp. I dream of a smart system with dual 850. Also the new smart system offers better power management. i e. I can program it to shut off when above 14-15mph.
blackhawk00001@reddit
I ride with a spare 625Wh battery in a backpack for my rail and will never consider another e-bike that does not allow for swapping batteries on the trail.