The Barncat Battery- No weld/no solder
- Thread starter Barncat
- Start date
Fairly close to buttoning this pack up.
Sprayed some rattlecan on the sidewalls, preassembled the tensioner screws/nuts. Because the copper screws are being used opposite their normal direction, each end must be carefully offhand slotted with a dremel and thin grinding wheel to accept a small flat blade screwdriver.
All the new cells are laid out and checked for voltage. A dozen or so were .01-.02V under and were quickly matched up with the simple charging jig shown. I trim the overwrap off the negative ends for maximum contact with the braided straps.
Third pic shows some of the grid pattern of 1/8" holes drilled in the right sidewall. These are exactly positioned to insert DMM leads to monitor voltage of each parallel group.
Some work to do on the lid, and the two 8ga leads to a QS8 connector.
Sprayed some rattlecan on the sidewalls, preassembled the tensioner screws/nuts. Because the copper screws are being used opposite their normal direction, each end must be carefully offhand slotted with a dremel and thin grinding wheel to accept a small flat blade screwdriver.
All the new cells are laid out and checked for voltage. A dozen or so were .01-.02V under and were quickly matched up with the simple charging jig shown. I trim the overwrap off the negative ends for maximum contact with the braided straps.
Third pic shows some of the grid pattern of 1/8" holes drilled in the right sidewall. These are exactly positioned to insert DMM leads to monitor voltage of each parallel group.
Some work to do on the lid, and the two 8ga leads to a QS8 connector.
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Pretty much done. Just need to drill 4 holes in the base for mounting on the bike, and have to solder up an adapter plug for the charger to QS8.
Anyone know whether amp output is adjustable on this charger? Voltage is, but current probably not... (edit- the current can be adjusted but it's already nominally maxed out at 3A, 84V with a 240W rating...)
Anyone know whether amp output is adjustable on this charger? Voltage is, but current probably not... (edit- the current can be adjusted but it's already nominally maxed out at 3A, 84V with a 240W rating...)
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eMark
100 kW
Really like the look (fit), practicality of your earlier (COG) location for ride safety ...
Don't see this battery location as practical IF that's how you now plan to locate your 21700 battery ...
Are you making a lengthier custom frame with seat a little closer to handle bars (see top photo)? Really like to cool-look of the top bike design ... not the top heavy design.
Have you yet arrived at a custom bike frame design that's the best fit for your heavy 21700 barncat battery?
Don't see this battery location as practical IF that's how you now plan to locate your 21700 battery ...
Are you making a lengthier custom frame with seat a little closer to handle bars (see top photo)? Really like to cool-look of the top bike design ... not the top heavy design.
Have you yet arrived at a custom bike frame design that's the best fit for your heavy 21700 barncat battery?
eMark- the green Orange County Choppers Schwinn is an unusual frame design that lent itself to the low battery/motor/controller mounting setup.
My 4 other builds all required putting the battery pack on the top tubes as they wont fit inside the triangle. They all handle great, the mass (12- 16 lbs) relative to one's torso is insignificant; all motorcycles have gas tanks in that arrangement. Aesthetically I suppose a triangular pack is preferable with bicycle conversions, but not possible with my design.
I had planned on building a custom aluminum full suspension frame using 1 x 3 rectangular tubing that would look similar to the Mongoose Blackcomb. The battery would be hung from a fairly horizontal top tube to look more integrated with the design, with a motorcycle style monoshock swingarm. Not going to get to that this FL season. I am going to try to build a sprag bearing freehub 24 inch rear wheel however...
My 4 other builds all required putting the battery pack on the top tubes as they wont fit inside the triangle. They all handle great, the mass (12- 16 lbs) relative to one's torso is insignificant; all motorcycles have gas tanks in that arrangement. Aesthetically I suppose a triangular pack is preferable with bicycle conversions, but not possible with my design.
I had planned on building a custom aluminum full suspension frame using 1 x 3 rectangular tubing that would look similar to the Mongoose Blackcomb. The battery would be hung from a fairly horizontal top tube to look more integrated with the design, with a motorcycle style monoshock swingarm. Not going to get to that this FL season. I am going to try to build a sprag bearing freehub 24 inch rear wheel however...
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eMark
100 kW
EDIT change from yesterday ....
Does your battery design NOT lend itself to any existing rear hub/pedal ebike design? Getting the impression you like to fabricate your own creations ... whether it be a new battery fabrication or redesigning an ebike frame to your specification.
Like you and a few others i'm also my own BMS (don't trust them) ... so can understand one reason for your non-BMS battery fabrication for ease of removing/replacing a weak/bad cell.
That said, doesn't removing the crank/pedals become illegal as a Clsss I, 2, or 3 ebike. What do you have against a rear hub motor and pedal power when needed as less desirable than your ebike motor/chain drive design.
Does your battery design NOT lend itself to any existing rear hub/pedal ebike design? Getting the impression you like to fabricate your own creations ... whether it be a new battery fabrication or redesigning an ebike frame to your specification.
Like you and a few others i'm also my own BMS (don't trust them) ... so can understand one reason for your non-BMS battery fabrication for ease of removing/replacing a weak/bad cell.
That said, doesn't removing the crank/pedals become illegal as a Clsss I, 2, or 3 ebike. What do you have against a rear hub motor and pedal power when needed as less desirable than your ebike motor/chain drive design.
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You're correct to assume I'm strictly a DIY builder.
When i was younger i built 3 different recumbent bikes from scratch, then years later designed and built a run of a dozen full suspension mtb frames from 7005 Easton aluminum tubing, including fabricating a large 500F oven to heat treat them in. Over the last 20 years I've built about 20 70's era Japanese cafe racers, but the supply of donor bikes pretty much dried up, so i switched to ebikes, with the same minimum weight maximum speed aesthetic.
IMO, hub motors are not only too heavy, but the weight is in the wrong place. Also after decades of serious cycling i can no longer sit on a conventional bicycle seat due to minor nerve damage, hence the flat platforms... so pedaling is out. I use inline skates for exercise.
Class 2 ebikes without pedals are legal up to 20mph. I keep a sharp eye out for the police (whom i support and respect btw) and hug the shoulder at under 20 whenever i see a cop car, though they don't really care anyway fortunately, in my experience. I have never once been stopped in thousands of miles either here in FL or up in our small town in east TN. Just use common sense. I always carry my drivers license (with motorcycle endorsement) as a potential bargaining chip just in case.
New pack on the charger ready for maiden voyage.
(Edit/update- this battery was well worth the build. I'm running 220 phase amps/140 battery amps into a Flipsky 75200. Target max of 60+mph achieved, with a 65lb bike that cost around $1400 in parts.)
When i was younger i built 3 different recumbent bikes from scratch, then years later designed and built a run of a dozen full suspension mtb frames from 7005 Easton aluminum tubing, including fabricating a large 500F oven to heat treat them in. Over the last 20 years I've built about 20 70's era Japanese cafe racers, but the supply of donor bikes pretty much dried up, so i switched to ebikes, with the same minimum weight maximum speed aesthetic.
IMO, hub motors are not only too heavy, but the weight is in the wrong place. Also after decades of serious cycling i can no longer sit on a conventional bicycle seat due to minor nerve damage, hence the flat platforms... so pedaling is out. I use inline skates for exercise.
Class 2 ebikes without pedals are legal up to 20mph. I keep a sharp eye out for the police (whom i support and respect btw) and hug the shoulder at under 20 whenever i see a cop car, though they don't really care anyway fortunately, in my experience. I have never once been stopped in thousands of miles either here in FL or up in our small town in east TN. Just use common sense. I always carry my drivers license (with motorcycle endorsement) as a potential bargaining chip just in case.
New pack on the charger ready for maiden voyage.
(Edit/update- this battery was well worth the build. I'm running 220 phase amps/140 battery amps into a Flipsky 75200. Target max of 60+mph achieved, with a 65lb bike that cost around $1400 in parts.)
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speaking of home powerwalls, here's mine - 13S/160P, approx 23kWh, double-sided, all recycled 18650-ies, not welded but in batt.holders for ease of exchange.
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Great idea! Can you tell us how you built the battery holders? Are they charged by solar or the grid?
How is it performing?
How are you monitoring the cells? What kind of BMS?
Is the power wall in a separate shed, away from the house?
raedy07- good that your large powerwall works well and that you utilize "free" solar. I've got a great site for that here at the FL house but I'm too nervous about having that much lithium attached to it... plus the building code people are very difficult, plus hurricanes...
Back to ebikes: as an update I'm pleased to report that my 3 Barncat batteries have functioned very well over a total of probably 8000-9000 miles on 5 different ebikes, 2 of which have no suspension, 1 has an air fork, the other two are full suspension. Mainly road use as intended with some gravel, but they've been subjected to all manor of bumps and vibration, and some hits hard enough to snap the zip ties that hold them to the frames. The cell groups need to be manually monitored for voltage balance but they self balance well. It's advisable to start with brand new cells. I usually disassemble a pack once a year or so to check everything and readjust. And I never ride in the rain- getting them wet is not a good idea, though a simple fabric waterproof cover could mitigate that.
I have 100 new Samsung 50s 21700 cells arriving soon to build another 20s5p pack basically identical to the one in my last post above on this page. The 5000ma capacity will add several miles to the already good range of the p42a pack, and the 25A rating with higher bursts is more than enough current.
Back to ebikes: as an update I'm pleased to report that my 3 Barncat batteries have functioned very well over a total of probably 8000-9000 miles on 5 different ebikes, 2 of which have no suspension, 1 has an air fork, the other two are full suspension. Mainly road use as intended with some gravel, but they've been subjected to all manor of bumps and vibration, and some hits hard enough to snap the zip ties that hold them to the frames. The cell groups need to be manually monitored for voltage balance but they self balance well. It's advisable to start with brand new cells. I usually disassemble a pack once a year or so to check everything and readjust. And I never ride in the rain- getting them wet is not a good idea, though a simple fabric waterproof cover could mitigate that.
I have 100 new Samsung 50s 21700 cells arriving soon to build another 20s5p pack basically identical to the one in my last post above on this page. The 5000ma capacity will add several miles to the already good range of the p42a pack, and the 25A rating with higher bursts is more than enough current.
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