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Gotway Monster Battery Info: DIY


Joey Serrin

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I have been looking into alternative battery sources to power one of my projects using a Gotway Monster Motor/circuit board. Does anybody have any information on..?

-voltage (working/full/empty charge voltages). I am confused on the newer 84v batteries and the working voltages 

-minimum capacity to safely run a 1600watt motor (not planning on using the wheel below 50% battery).

-any suggestions on DIY battery and what is the most reliable 18650 cell to use 

Thank you for your help! 

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  • 1 month later...

1600Watt / 67.2vols = 23 amps. But more likely you want to allow your motor to to to 3,000Watt for short bursts so now you need 46 Amps. So you should make sure your battery design can supply 50Amps minimally. But a better margin is to use 3.7V for cell voltage times 16 cells is 59.2 volts.  So lets call it 59Volts.  

1600Watt / 59Volts =  27 amps. at 3,000watts 54 amps. So a 4P battery design will need to use cells capable of 27/4 = 6.74 Amps nominal and 54/4 = 13.5 amps.

So I would think you want to use 4P with cell capable of delivering 13 amps max current. Typically they are rated like 10 amps and 20amps.

If you use a circuit board with 84Volts you can do the math.

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  • 3 months later...
On 31/03/2017 at 1:39 AM, Joey Serrin said:

I have been looking into alternative battery sources to power one of my projects using a Gotway Monster Motor/circuit board. Does anybody have any information on..?

-voltage (working/full/empty charge voltages). I am confused on the newer 84v batteries and the working voltages 

-minimum capacity to safely run a 1600watt motor (not planning on using the wheel below 50% battery).

-any suggestions on DIY battery and what is the most reliable 18650 cell to use 

Thank you for your help! 

Calling the 20 cell batteries "84volt" is something of an Americanism, it is its full maximum voltage, everywhere else it would be called a 72 Volt battery. So full and also charge voltage 84V, working, 72V minimum (absolutely flat) 60 volts.

Minimum capacity depends on power capability of the cells and whatever range/duration you are looking for. Assuming you are using 72 Volt batteries and sustained is 1600W then you do not want to be pulling more than 1C from the cells continuously  since C is around the 3 Amps mark for most good cells on the market and 1600W/72= 22 Amps you would need a 20S7p pack to draw 1600W for 1 hour. Assuming range is not an issue and peak current is (say) twice that (so max 44 Amps) then a cell like the LG HG2 can reach 20 Amps and a 20S3P pack could cope with short bursts up to 3200W. However if 1600W were sustained that pack would last for not much over 20 minutes right down to flat.

To build a battery yourself you need a suitable BMS and a spot welder to connect the cells. @Jason McNeil is probably the best person you know to discuss the best cells to use. An off the shelf Gotway pack might be your best bet.

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On 31.3.2017 at 2:39 AM, Joey Serrin said:

I have been looking into alternative battery sources to power one of my projects using a Gotway Monster Motor/circuit board. Does anybody have any information on..?

-voltage (working/full/empty charge voltages). I am confused on the newer 84v batteries and the working voltages 

-minimum capacity to safely run a 1600watt motor (not planning on using the wheel below 50% battery).

-any suggestions on DIY battery and what is the most reliable 18650 cell to use 

Thank you for your help! 

You are not running your Monster with a 67 Volt Pack, or? That would be highly dangerous! as under 61/62 volt the motor is undervoltaged, and even 67 volt are not that good for a Monster....as it is just about at 25% of a 72/84volt system.

I allready wondered as you bought a Monster without batteries, where you will get the 20cell packs from...and just saw some crytic "i use 1000wh for my monster"....

Just to clear it up: 

Monster, V3s+, Acm v2s and some of the new coming wheels like Tesla, mten3 ALL need 20serial cell packs = 72volt nominal/84 volt maximal.

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Here is one of my 84V external pack.
extBattC.jpg.7e2b52b0ad7908c44a9ba8f9d0d3362b.jpg

I used to solder my pack but is tedious. I happened to find 4 packs of 5s3p LG MJ1 cells(3500mAh, 10A discharge rate), unused, tested to be slightly better than NCR18650GA in capacity, put on balancing circuits then I'm happy with it ever after. I use this to rider long trips including three 100km without rest.

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  • 2 weeks later...

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