Building a high Amp output battery question

Batteries, Chargers, and Battery Management Systems.
maarkmohamed   1 mW

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Re: Building a high Amp output battery question

Post by maarkmohamed » Jan 12 2019 1:04pm

Yea its going to be for a electric dirt bike, just trying to figure out exactly everything i need right now. You guys have shown me many options i have to figure out which is best.

999zip999   100 GW

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Re: Building a high Amp output battery question

Post by 999zip999 » Jan 12 2019 3:15pm

Again asking about the exact controller and the exact motor.
Yescom 1,000 watt dd with dilled covers.

shaglord   1 mW

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Re: Building a high Amp output battery question

Post by shaglord » Jan 13 2019 8:02am

What about running a higher voltage and fewer amps = equal watts.

Good for a high performance (limited range) EV build. Thinner cables, smaller controller components :)

What about two wheel drive?

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izeman   10 GW

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Re: Building a high Amp output battery question

Post by izeman » Jan 13 2019 10:58am

999zip999 wrote:
Jan 12 2019 3:15pm
Again asking about the exact controller and the exact motor.
Why would that matter? He's just asking for advice on battery building, and he gave info about max amps and voltage.

999zip999   100 GW

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Re: Building a high Amp output battery question

Post by 999zip999 » Jan 13 2019 2:12pm

It all in the complete design . Like to see the whole picture. As mistakes and confusion have already been straiten out. Don't what to haul in the back on a trailer.

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Chalo   100 GW

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Re: Building a high Amp output battery question

Post by Chalo » Jan 13 2019 4:14pm

maarkmohamed wrote:
Jan 11 2019 11:44am
The only reason why I'm not willing to use other batteries besides the 18650 is because I know how to assemble and work with 18650 cells, theres countless videos on them which makes it easy for me.
Prismatic cells with threaded terminals are infinitely easier to deal with than 18650s. I have used the Panasonic 25Ah prismatic cells as used in VW and Ford hybrids. It has unimpressive energy density, but huge current capability, and it's a piece of cake to build into packs. I think you'd still need 2P pack architecture to reach 500+ amps.

You seem to want maximum discharge rates north of 30A/cell for the little guys. Customary means of tabbing and welding them are nowhere near being suitable for such current. What's your plan?
This is to express my gratitude to Justin of Grin Technologies for his extraordinary measures to save this forum for the benefit of all.

999zip999   100 GW

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Re: Building a high Amp output battery question

Post by 999zip999 » Jan 14 2019 10:56am

I saw your packs and like them but hard to fit on my style bike and a little heavy.

maarkmohamed   1 mW

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Re: Building a high Amp output battery question

Post by maarkmohamed » Jan 14 2019 12:36pm

Being realistic right now, if i build a 26s 14ah battery, it would be a bit above 96v nominal 100+ hoc, and each cell would put out 20 amps continuous that would leave me with almost 27kw continuous. If i push the battery a bit and draw 25 amps from each cell which i could do for a few seconds even draw 30 amps from the cells for a few seconds which has been tested, id be pushing 30+kw into the 40kws. Now with a bike thats going to be less than 200lbs im really really being overkill. the alta redshift which is like 270lbs says they have a maximum output of around 20kw. And people who ride it say they dont even use the highest mode much because its too much power. So i think i should be realistic with the power im looking for and not be dumb. 20+kw of power continuous should be plenty.

maarkmohamed   1 mW

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Re: Building a high Amp output battery question

Post by maarkmohamed » Jan 14 2019 12:39pm

Also if someone could confirm this for me. at 26s the nominal voltage would be about 96, when its fully charged (HOC) would the voltage be 4v x the 26 cells in series? so something like 104v?

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izeman   10 GW

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Re: Building a high Amp output battery question

Post by izeman » Jan 14 2019 1:22pm

maarkmohamed wrote:
Jan 14 2019 12:39pm
Also if someone could confirm this for me. at 26s the nominal voltage would be about 96, when its fully charged (HOC) would the voltage be 4v x the 26 cells in series? so something like 104v?
Not ALL 18650 cells are the same, but as a rule of thumb you can calculate with 3.65V nominal on the conservative side (up to 3.75V some others say), and up to 4.2V for fully charged.
So 26s would be 95V nominal and 109V fully charged.

maarkmohamed   1 mW

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Re: Building a high Amp output battery question

Post by maarkmohamed » Jan 14 2019 1:42pm

izeman wrote:
Jan 14 2019 1:22pm
maarkmohamed wrote:
Jan 14 2019 12:39pm
Also if someone could confirm this for me. at 26s the nominal voltage would be about 96, when its fully charged (HOC) would the voltage be 4v x the 26 cells in series? so something like 104v?
Not ALL 18650 cells are the same, but as a rule of thumb you can calculate with 3.65V nominal on the conservative side (up to 3.75V some others say), and up to 4.2V for fully charged.
So 26s would be 95V nominal and 109V fully charged.
thank you for clearing that up

999zip999   100 GW

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Re: Building a high Amp output battery question

Post by 999zip999 » Jan 14 2019 2:59pm

The hard part is making a series buss bars to handle the current in the 18650 format.

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izeman   10 GW

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Re: Building a high Amp output battery question

Post by izeman » Jan 14 2019 3:20pm

999zip999 wrote:
Jan 14 2019 2:59pm
The hard part is making a series buss bars to handle the current in the 18650 format.
Drilling single stranded copper wire as used in home installation is how the guys building power walls do it.

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