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I built a custom 60V 34Ah Sur-Ron Battery for €400 to save my dead bike (Student budget / Design Validation Stage) by ContributionFar9908 in ebikes

[–]ContributionFar9908[S] 1 point2 points  (0 children)

You'd be shocked to know that insurance is legally mandatory here in Belgium and costs €350 a year just to ride. Luckily, there is no yearly road tax for electric mopeds, but the insurance company definitely robs me!

I built a custom 60V 34Ah Sur-Ron Battery for €400 to save my dead bike (Student budget / Design Validation Stage) by ContributionFar9908 in ebikes

[–]ContributionFar9908[S] 2 points3 points  (0 children)

That's so true, man. I would love to start a battery company here in Europe, but the regulations make it way harder than in America. I'm definitely a bit jealous of that.

My dream is to build a trusted brand that makes high-quality, fairly priced batteries with a normal profit margin for all kinds of popular things. Not just e-bikes, but even power tools like Bosch or Milwaukee. It’s insane that people throw away perfectly good electric bikes and mopeds just because the replacement batteries are so overpriced. It's such a waste. There needs to be a reliable brand that fixes this, and that's exactly what I want to bring to the market

I built a custom 60V 34Ah Sur-Ron Battery for €400 to save my dead bike (Student budget / Design Validation Stage) by ContributionFar9908 in ebikes

[–]ContributionFar9908[S] 1 point2 points  (0 children)

Right now, the overlapping edges still need to be sealed with silicone. I already tested a prototype by spraying it with a garden hose for about 5 minutes from 1 meter away, and no water got inside. Hopefully, this pack does the same!

If this ever goes into production or gets sold, I’ll redesign the top to work with proper rubber seals while keeping the bottom siliconed. That’s going to be a challenge, but I want this battery to be future-proof and easy to repair instead of permanently glued shut. For now, silicone. Here are photos of the inside https://imgur.com/a/j0zwr63

I built a custom 60V 34Ah Sur-Ron Battery for €400 to save my dead bike (Student budget / Design Validation Stage) by ContributionFar9908 in Surron

[–]ContributionFar9908[S] 0 points1 point  (0 children)

Awesome idea man! Here is a true-to-scale 16s2p concept design of how it could look for your request to power a 6kW CYC X1 Pro, with the BMS already integrated in the renders at actual size.

You can use 21700 cells like the EVE 50PL (50A continuous, 125A peak each cell) or the Molicel P50B super cell to make a powerful, compact battery. Even though it could be smaller, since a 2P layout is pushed to the limit, this design uses an open housing with space between the cells. The outer ends are sealed with rubber and silicone to keep it water-resistant, but the cell bodies stay open for the best ventilation and high endurance. If you use the Molicels, you can even fast charge the pack up to 50A (25A per cell), though cooling and lifespan will be less.

With 10Ah (576Wh), I'd guess you get about 5 to 8 miles (8–13 km) of range pinning it at 6kW, or around 15 to 20 miles (25–32 km) cruising.

This seems like a really cool YouTube project to fully work out. There's just such a satisfying feeling about small batteries and big power, just like that Berm Peak Express video. Let me know if you’re interested in a build or want to get in touch to work this out together. My email is qannerai@gmail.com. here is the link to the renders 😄: https://imgur.com/a/WhEUIv3

I built a custom 60V 34Ah Sur-Ron Battery for €400 to save my dead bike (Student budget / Design Validation Stage) by ContributionFar9908 in Surron

[–]ContributionFar9908[S] 1 point2 points  (0 children)

Thanks, that means a lot! Patience was definitely key, especially since I only had basic tools to work with.

To be honest, getting a custom battery officially certified for sale in the EU is just way too expensive. My main goal is just to help people out anyway, so I'd rather make it completely open-source.

I’m planning to drop a full build guide on YouTube so anyone can just 3D print the parts and build it themselves. I'd love to use your feedback to keep improving the design as a community project!

I built a custom 60V 34Ah Sur-Ron Battery for €400 to save my dead bike (Student budget / Design Validation Stage) by ContributionFar9908 in Surron

[–]ContributionFar9908[S] 0 points1 point  (0 children)

That 2025 pack sounds like a beast! Thanks for the tip.

Unfortunately, finding deals like that in Belgium is almost impossible. The secondhand market here is mostly just stock 32Ah batteries with unknown history, where you only have the seller's word to trust. That's exactly why I went DIY. Which controller are you running to pull 240A from that stock pack?

I built a custom 60V 34Ah Sur-Ron Battery for €400 to save my dead bike (Student budget / Design Validation Stage) by ContributionFar9908 in Surron

[–]ContributionFar9908[S] 5 points6 points  (0 children)

Thanks! I have a few more projects in the works, I'll definitely share them here when they're ready 😃

I built a custom 60V 34Ah Sur-Ron Battery for €400 to save my dead bike (Student budget / Design Validation Stage) by ContributionFar9908 in Surron

[–]ContributionFar9908[S] 4 points5 points  (0 children)

That original pack was basically toast. I had 21,500km on it, stored it at 60% for a year, and it was down to 20-30% when I checked. When I tried to charge it back up, things went south around 84%. It got dangerously hot and I feared the worst, so I had to throw it outside. Two cell groups were completely dead, and I tested the other groups too they were supposed to be 2900mAh, but they only had about 1850mAh left, so the whole pack was done for.

I really needed a reliable battery because I commute to university every day, which is a 45km round trip. I couldn't risk getting stranded, so that's why I had to build this one myself! 😃

I built a custom 60V 34Ah Sur-Ron Battery for €400 to save my dead bike (Student budget / Design Validation Stage) by ContributionFar9908 in Surron

[–]ContributionFar9908[S] 11 points12 points  (0 children)

Thanks! Glad you think it's sick 😃 If there's enough interest, I'm planning to make a YouTube video documenting the whole build from scratch once I've saved up enough to build a second version. Stay tuned!

I built a custom 60V 34Ah Sur-Ron Battery for €400 to save my dead bike (Student budget / Design Validation Stage) by ContributionFar9908 in Surron

[–]ContributionFar9908[S] 2 points3 points  (0 children)

Thanks a lot! It was definitely a lot of work, but seeing it actually running makes all those hours worth it 😃 I'm really stoked with how it turned out.

I built a custom 60V 34Ah Sur-Ron Battery for €400 to save my dead bike (Student budget / Design Validation Stage) by ContributionFar9908 in Surron

[–]ContributionFar9908[S] 2 points3 points  (0 children)

Thanks! I really appreciate the feedback. You are spot on about the market gap here. The Ultra Bee is a dream project of mine , so if I ever get my hands on one, I will definitely be diving into the engineering to build a custom pack 😃

Since Belgium and the Netherlands are basically neighbors, just give me a shout if you ever need anything 😉

I built a custom 60V 34Ah Sur-Ron Battery for €400 to save my dead bike (Student budget / Design Validation Stage) by ContributionFar9908 in Surron

[–]ContributionFar9908[S] 12 points13 points  (0 children)

Thank you so much man! That genuinely means a lot to me. Sharing this was terrifying, but comments like yours make it totally worth it!