Making your own tec pack?

[sdcoffeeroaster]

I just returned from my first ride with the free Chinese replacement battery. This is more like it. 15.9 miles and 1093 feet of climbing. That's from a 158 wh battery that costs $34. The seller has a stock pile in the US so shipping is free and fast. I should get the more powerful, 249 wh US made battery by Friday. That one should give me almost 25 miles extra range depending on how much assist I use. I don't see any downsides to this sort of DIY TEC pack compared to the std TEC pack. It only adds 2 lbs to the bike weight and the battery is easily user replaced while extending the useful life of the native Focus battery. For $110. you get the battery, housing and charger. The longer range version is a bit more expensive because of the battery. And I'm not sure how many charges I'll get out of the Chinese battery but I don't intend to run it flat all the time now, maybe just to 12 miles.

 

[Gspot]

Maybe I should make a pack for the wife? So are you using Eco/Trail? I think I would use it first then
go to the internal to have a better idea of range.

 

[sdcoffeeroaster]

Maybe I should make a pack for the wife? So are you using Eco/Trail? I think I would use it first then
go to the internal to have a better idea of range.

Yes ECO and Trail on the last ride. Lots of climbing was mostly Trail. Yes I always use it up first. I'm getting good at switching over even if it quits on a hill. I added the elastic band so the cable doesn't rattle and found that the 1" plastic leg caps fit perfectly to keep dust out of the Rosenberger.

 

[stiv674]

Just to jump in to your conversation, do you think THIS would work if I connected a Rosenberger plug to it?

 

[Daslevin]

Just to jump in to your conversation, do you think THIS would work if I connected a Rosenberger plug to it?

Yes if it fits in place. Maybe ill buy this. UPP Trinkflaschenakku Rahmenakku 36V 10,5AH Samsung , Pedelec Akku Umbausatz | eBay

 

[stiv674]

Yes if it fits in place. Maybe ill buy this. UPP Trinkflaschenakku Rahmenakku 36V 10,5AH Samsung , Pedelec Akku Umbausatz | eBay

That looks even better, I guess any battery will work in theory... ?

Maybe @TrailwattsUK could just put a Rosenberger plug and lead on a Specialized extender?

 

[Daslevin]

Sounds like a good solution. But they were busy...

 

[stiv674]

Sounds like a good solution. But they were busy...

Well this way he doesn't have to test it, it would be at our own risk to use it...

I did think about covering the data pins up and plugging the TEC battery in to see what happened, not sure if I'm brave enough though

 

[sdcoffeeroaster]

Just to jump in to your conversation, do you think THIS would work if I connected a Rosenberger plug to it?

Yes it looks like it would work. Almost any 36v li-ion battery that you can mount would work. I don't even have an on-off switch on mine and it works perfectly. That one is pretty compact and a good price too and looks like it uses 2600 mah cells.

 

[sdcoffeeroaster]

Well this way he doesn't have to test it, it would be at our own risk to use it...

I did think about covering the data pins up and plugging the TEC battery in to see what happened, not sure if I'm brave enough though

The data pins on my rosenberger plug are not connected and it works perfectly. I've done 5 rides with it so far. I do another ride tomorrow with the newest pack I just received that is 250 wH and uses Sanyo 18650GA cells. The nice thing about my DIY pack is that the hoverboard batteries are pretty common now and seem to be reliable too. I did get one weak one though so there is that to consider.

 

[sdcoffeeroaster]

Yes if it fits in place. Maybe ill buy this. UPP Trinkflaschenakku Rahmenakku 36V 10,5AH Samsung , Pedelec Akku Umbausatz | eBay

Looks like another good option and lots of range and 378 wH like the TEC pack.

 

[Daslevin]

Looks like another good option and lots of range and 378 wH like the TEC pack.

Yeah and for half of that price. Today i recived my Rosenberger plug. So show is going on ...

 

[BlushingCrow]

The form factor of this one intrigues me:

Pardon our interruption...

10s2p in 10cmx8cmx7cm

I'm wondering if I could fit that in between the shock and the frame really low down.

 

[sdcoffeeroaster]

Yeah and for half of that price. Today i recived my Rosenberger plug. So show is going on ... View attachment 39600

Where did you get the cable? Nice.

 

[sdcoffeeroaster]

OK, first ride with the 250 wH battery. I decided to do the entire ride in trail mode (set to medium) and do as much climbing as fast as I could. It's going to be close to 100 today and for the next week so I got an early start. One bar on my Focus battery was only 5 miles and 700 feet of climbing as a reference. The new pack only went 14.3 miles and 1902 feet of climbing. While that doesn't sound like much there was almost zero coasting on this ride and I picked the hardest, roughest ride I could find near my house and never used ECO, only trail and Boost once. I had about 1000 feet in the first 4 miles! So I think this higher end battery is a winner and would probably go 20 miles and 1500 feet using ECO/Trail in a about a 60/40 ratio, which is my normal ride. I ended up the ride at 23 miles and 3434 feet of climbing with lots 3 bars left on the main battery.

 

[Daslevin]

Where did you get the cable? Nice.

Linergy

 

[sdcoffeeroaster]

Linergy

Yeah they don't ship to the US or I would have bought from them. I was lucky to find someone that was willing to sell the cable for 20 euros plus 16% VAT and ship it too. Wish I had the right angle Rosenberger but the straight one seems to work too.

The form factor of this one intrigues me:

Pardon our interruption...

10s2p in 10cmx8cmx7cm

I'm wondering if I could fit that in between the shock and the frame really low down.

Yes, it should. My first one was 13.5 cmx8.5cm x5.8cm so not as tall as that one. And you can find similar batteries on ebay and alliexpress but not with the Rosenberger plug. The newer one I have is similar but a bit narrower. I've now mounted mine down pretty low using the stock shock. You just have to find something that can hold it in place and protect it a bit. That battery should fit in one of these once you removed the internal dividers. I did make an aluminum mounting plate for mine and had to extend two of the straps to wrap around the down tube.

 

[Gspot]

Unless someone in the EU would ship it to the US? I would be willing to pay a small fee. I would need one with the right angle though. The one from NextWarehouse is pushed back again to 10/31.

 

[sdcoffeeroaster]

Unless someone in the EU would ship it to the US? I would be willing to pay a small fee. I would need one with the right angle though. The one from NextWarehouse is pushed back again to 10/31.

It's amazing how tough this part is to get in the US. The Rosenberger manufacturer was willing to sell the right angle one to me but I had to buy 10 of the at 20 euros each plus 16 VAT AND I had to arrange my own shipping from Europe. I'm not sure how to even go about that. So I paid to have 5 of them shipped from my other source, same price, not right angle and 40 euros shipping cost thru DHL but it eventually arrived through USPS stateside.

I did have one small hiccup with the new battery. The cable is routed differently. So I really had too much cable inside my pack. It works but if I make a 2nd one I'll have to make it shorter. In the picture the new 250 wH Fullbattery (purple) is slid up higher in the housing (more clearance there for the cable) before zipping it up and the cable has to run up over the top rather than down the side like I did with the Chinese batteries (blue).

 

[sdcoffeeroaster]

I finally got back out on the trails today after our heat wave here. I used the newer USA battery today and went 23 miles and 1746 feet of climbing before it quit. 26 mile ride so I only used a very small portion of the native battery.

 

[Daslevin]

I finally got back out on the trails today after our heat wave here. I used the newer USA battery today and went 23 miles and 1746 feet of climbing before it quit. 26 mile ride so I only used a very small portion of the native battery.

It seem to be that your solution is very reliabel. Have to get my arm fixed so i can go on. Its so frustrating, sitting at home, do nothing, and the Summer goes by... everyone enjoying their bikes... ?

 

[sdcoffeeroaster]

It seem to be that your solution is very reliabel. Have to get my arm fixed so i can go on. Its so frustrating, sitting at home, do nothing, and the Summer goes by... everyone enjoying their bikes... ?

Remind me again about your arm? I struggled from Nov to almost April 2018 in lots of pain and discomfort after my crash. While I still have lingering issues from collar bone break and multiple other bone breaks, I'm so glad I can ride again. Just be patient and go in small steps and don't get re-injured. The down time now will fade into the past. Probably the best time to be out if that's possible with the covid pandemic going around. I have not ridden with anyone since February.

 

[Ongy]

Thanks everyone for the info in relation to the DIY Tec packs. A supplier for the Rosenberger 90 degree connector is Ebikes.ca, Grin Technologies. I have ordered 2, just waiting on these as my batteries arrived today, Molicel's 42PA's. I am building 10S2P packs, 36v 8.4ah packs, one to go in a bag on the frame and another for my backpack. These should give me a decent amount of range and be quite small, rather than building one 10S4P pack.

 

[BlushingCrow]

Thanks everyone for the info in relation to the DIY Tec packs. A supplier for the Rosenberger 90 degree connector is Ebikes.ca, Grin Technologies. I have ordered 2, just waiting on these as my batteries arrived today, Molicel's 42PA's. I am building 10S2P packs, 36v 8.4ah packs, one to go in a bag on the frame and another for my backpack. These should give me a decent amount of range and be quite small, rather than building one 10S4P pack.

I'm also liking this approach. Will be interested in any pics of the build and mounting you do. Plan to do the same next year.

 

[sdcoffeeroaster]

Thanks everyone for the info in relation to the DIY Tec packs. A supplier for the Rosenberger 90 degree connector is Ebikes.ca, Grin Technologies. I have ordered 2, just waiting on these as my batteries arrived today, Molicel's 42PA's. I am building 10S2P packs, 36v 8.4ah packs, one to go in a bag on the frame and another for my backpack. These should give me a decent amount of range and be quite small, rather than building one 10S4P pack.

I see that Grin has a very short right angle Rosenberger plug but it is also out of stock right now. The straight plugs I'm using are working out good for me but I ended up routing them more directly and added a zip tie feature at the top mount that is normally used for the TEC pack. I'm using a 250wH 2 lb battery (10s2p) for every ride now. I just use it until I hit around 15 miles and then change over to my native battery, which only takes 5-10 seconds to do. That keeps me from running down my AUX battery to where it will hurt it's life and I always have it available if I run down the native battery pack since I can get about 20-23 miles out of the AUX pack. I've now done about 10 rides with my DIY pack without any issues. I doubt I will ever run both batteries down on a ride since the majority of my rides are 20-25 miles.

I've built two packs now. The first one did lead to disconnects twice due to poor off angle routing. The right angle plug would be ideal but the straight plugs are now working for me with no disconnections as long as I am careful connecting up straight. The elastic around the down tube keeps the plug from rattling around when not in use and the 1" soft plastic cap I found a Home Depot keeps the dust and dirt out of the plug. I have 3 extra straight Rosenberger plug/cables for sale if anyone is interested. The high quality battery was the biggest expense in all of this at $129. My backup battery from China at $34. is OK and gives 10-12 miles but who know how long those batteries will survive.

 

[themoon]

Finally managed to assemble a battery pack, hopefully will find time to test it this weekend It is a bit on the longer side, but 378WAh, same as TEC.

I've used rosenberger connectors both as the outputs and inputs to the pack in hopes of using bike's charger... but seems it won't work that way. When connected to the battery, charger starts to blink red; when the charger is first connected to the bike and starts charging it (and there is a usual click after a couple of seconds) -> and then I quickly switch it to charge the pack, its lights just go out (and do no come back even if I start to charge the bike itself). Wonder if it is actually charging at the point.

Did anyone experiment with using the "native" charger for custom packs? I think Booz uses it, so should be possible in theory... doubtful that they have the same access to data protocols as in TEC though

 

[sdcoffeeroaster]

Finally managed to assemble a battery pack, hopefully will find time to test it this weekend It is a bit on the longer side, but 378WAh, same as TEC.

I've used rosenberger connectors both as the outputs and inputs to the pack in hopes of using bike's charger... but seems it won't work that way. When connected to the battery, charger starts to blink red; when the charger is first connected to the bike and starts charging it (and there is a usual click after a couple of seconds) -> and then I quickly switch it to charge the pack, its lights just go out (and do no come back even if I start to charge the bike itself). Wonder if it is actually charging at the point.

Did anyone experiment with using the "native" charger for custom packs? I think Booz uses it, so should be possible in theory... doubtful that they have the same access to data protocols as in TEC though

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Nice. I just bought a $10. 2A charger and used the std two wire plug from the hoverboard pack. It's a nice slow charge and doesn't take long for a 250wH pack. What battery/BMS did you use to get it to fit? What is the weight? Mine is just about 2 1/4 lbs and pretty low CG.

 

[themoon]

Well, to be honest, I just orchestrated the process of the assembly: bought the pack, connectors, selected batteries etc. I did not do the soldering part -> offloaded this to local specialist; there are quite a lot in my country nowadays. Batteries used are 20 x 21700 LiitoKala's 5000mah version. Weight is about 1.7 kilos and resulting height is 27cm. It could be 3cm less if I did not use connectors as I did - basically they are sticking inside the case. Not sure about its CG, guess pretty uniform... will see during the first ride, I guess Your pack certainly looks more compact.

A note about magnets in the connectors - they are really strong, it takes noticeable force to disconnect them. Probably that's a good thing though.

 

[sdcoffeeroaster]

I made a small change to my DIY TEC pack when I noticed the velcrow straps starting to leave some minor markings (light scratches I think) on CF down tube. I don't really like how this padding looks and I'm still searching for the most ideal battery container. But this is effective and works.

 

[themoon]

I think it will look okay, esp if you would install black colored padding (this one looks gray?). On the other hand, these holes will fill up with dirt...

You can also try transparent anti-gravel tape I guess. The one I use is also self-adherent, so easy to install and protects quite decently. The only thing is, it is not matte, so creates a bit of gloss - but barely noticeable.

On my end I decided to rebuild the battery, to make it 24 cm is length, so that it will fit to standard bottle cage container not hitting the tube. Still in progress, will post here once completed