Go Back   DIY Go Kart Forum > Building Plans And Advice > Electric Projects

Notices

Reply
 
Thread Tools Display Modes
  #1  
Old 11-02-2019, 09:39 AM
maxg34 maxg34 is offline
Junior Member
 
Join Date: Nov 2019
Posts: 4
Thanks: 0
Thanked 0 Times in 0 Posts
Default 48v 1800 vs 60 2000

Is the additional weight required to support the extra 200 watts worth it? Or would going to 72v 3000 more bang for the buck? Seems like adding 2 batteries for 1000 watts as opposed to 1 battery for 200 is the way to go. Thoughts?
Reply With Quote
  #2  
Old 11-02-2019, 10:20 AM
itsid's Avatar
itsid itsid is offline
Moderator
 
Join Date: Jul 2013
Location: Ruhrpott [Germany]
Posts: 11,045
Thanks: 1,482
Thanked 4,589 Times in 3,464 Posts
Default

depends on the motors in question..

but sure if the total power to weight ratio is better,
then that's the better solution.

That not only includes the battery though, difference in motor weight also has to be taken into account, I doubt the controller weight difference will matter much tbh, so we'll leave that aside.

But what about ride time?
I mean sure you add batteries,
but you do NOT add capacity at all

assuming 45Ah batteries for example
you'll have 60V 45Ah on and 2kW (for ease of calc assuming that's electric power)
so max ride time on full power ~1:21h

with a 3kW Motor
you still have just 45Ah (this time @72V) but drain 3kW
and you reduce the ride time to ~1:04 h

And since you cannot completely drain a battery without destroying it....
that's even 20% less really 1:04h for the 60V 2KW motor and just 51mins for the 72V 3kW version

depending on the battery sizes, you might drop below your required ride time

'sid
__________________
Jokes about german sausage are the wurst.
Reply With Quote
  #3  
Old 11-02-2019, 12:10 PM
maxg34 maxg34 is offline
Junior Member
 
Join Date: Nov 2019
Posts: 4
Thanks: 0
Thanked 0 Times in 0 Posts
Default

Ahh..so if my math is correct, if i'm using, say...6 18Ah SLA's for the 72v set up, im looking at approx 20 min. of run time?
Unless I up the Amp Hrs to 55+ on all 6 batteries, but then its a cost effectiveness issue.

Even if I went 72v lithium ion, that would address the weight concern, but if its still 20Ah, I have the same short run time.

Came across this on Amazon and got my wheels spinning

https://www.amazon.com/Brushless-Con.../dp/B07KR2YJ1K
Reply With Quote
  #4  
Old 11-03-2019, 03:37 AM
itsid's Avatar
itsid itsid is offline
Moderator
 
Join Date: Jul 2013
Location: Ruhrpott [Germany]
Posts: 11,045
Thanks: 1,482
Thanked 4,589 Times in 3,464 Posts
Default

well at worst.. yes

runtime depends on actual current draw of course,
so if you're coasting down a road pulling no more than 200Watts off the motor,
you can do that for hours ...
but if you floor the pedal you end up with empty batteries after just a few minutes.

and it doesn't matter much if you're using SLAs or some sort of LiIon pack

Motor controllers have a low voltage protection to prevent the batteries from getting drained past their recovery point.
So the extra juice you can squeeze out a deep cycle SLA is as pointless as the extra a LiIOn is able to provide unless your controller is programmable.
(Usually those keep cheap lead acid wet cells alive just fine)

Only difference is weight and price..

'sid
__________________
Jokes about german sausage are the wurst.
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -6. The time now is 06:51 AM.