DIY Electric Car Forums banner
21 - 40 of 44 Posts

·
Registered
Joined
·
4,005 Posts
One style is the a50qs or a30qs

Here's the datasheet for the 30: http://www.discountfuse.com/v/vspfiles/downloadables/Ferraz/PDF/a30qs.pdf

For this one, you'd probably want somewhere around a 125A to 150A fuse, depending on what you think typical usage will be, and how you want the fuse to behave.

For example: I have a 400A controller. I usually pull up to 220A. Flooring it I would see > 300A for < 2 seconds. I could use a 125A fuse that would allow 350A for 2 seconds, so in the unlikely event my controller failed full on, I would just need to hold the brakes for a few seconds for the fuse to cut power (In case my manual cutoff didn't work/I panic etc).

Currently I have a 400A fuse that likely would never burn without a full pack short. I need to get a couple smaller ones for better protection.
 

·
Registered
Joined
·
30 Posts
Discussion Starter · #24 ·
thank you for the datasheet..

wow.. but you I am sorry you lost me..
don't understand: "how I want the fuse behave"
i will drive mild

so for the controller in my last drawing, with;
--
The peak input current: 300A
The peak output current (1 min): 600 A
--
which fuse do you recommend?

thx


One style is the a50qs or a30qs

Here's the datasheet for the 30: http://www.discountfuse.com/v/vspfiles/downloadables/Ferraz/PDF/a30qs.pdf

For this one, you'd probably want somewhere around a 125A to 150A fuse, depending on what you think typical usage will be, and how you want the fuse to behave.

For example: I have a 400A controller. I usually pull up to 220A. Flooring it I would see > 300A for < 2 seconds. I could use a 125A fuse that would allow 350A for 2 seconds, so in the unlikely event my controller failed full on, I would just need to hold the brakes for a few seconds for the fuse to cut power (In case my manual cutoff didn't work/I panic etc).

Currently I have a 400A fuse that likely would never burn without a full pack short. I need to get a couple smaller ones for better protection.
 

·
Registered
Joined
·
4,005 Posts
High current DC fuses are very different from the fast-acting fuses most people are accustomed to.

Your fuse is not going to protect your electronics, just your batteries and cabling.

How you size the fuse will determine if it acts as a slow-blow or really slow blow fuse in something less than a full short circuit. Even in a full short, it's possible the fuse wouldn't blow if the batteries can't put out enough current for the fuse to trip quickly.

For your system, to start with I'd recommend using a 150A fuse if using the style mentioned above, or one with a similar burn curve if you use a different brand.

Then once your system's running you can get measurements for actual usage, and add an additional fuse with a lower rating if appropriate. That's what I need to do with mine.
 

·
Registered
Joined
·
30 Posts
Discussion Starter · #26 ·
finale?

hello..

hereby is my last drawing for the daihatsu trimobile..

I just put one 20A charger for it to make the scheme simple :)
hope anyone care to send input, before I blow anything.. :)

thank you
 

·
Registered
Joined
·
3,141 Posts
Is that charger specifically designed to charge 4 batts in parallel that are also connected in series? If not they're all shorted.
I assumed that it was one 12V charger that could be switched to each battery sequentially. That would require a 2P4T selector switch of appropriate rating. That would work, but is very inconvenient. Four separate chargers with isolated outputs would be a more practical solution, and a single 5 position connector could be used. :)
 

·
Registered
Joined
·
30 Posts
Discussion Starter · #34 ·
update

Hi friends,

Just want to update on my projects..
please visit biobemo.tumblr.com to see the progress..

Yesterday was the first day for the bemo see the outside world.
The controller reach 71 degress celcius not long after i failed to drive the vehicle on to a steep road.

I am searching for a solution to cool the controller.. or to find the mistake I did, which causing it.
 

·
Registered
Joined
·
30 Posts
Discussion Starter · #40 ·
No It doesn't have amp meter yet..
i use a note book connected to the controller.
i will check..

The bemo apply direct-drive system.
I thought that will save some weight..
Because I got the bemo in used condition, I think I must take the axle apart and ask somebody who can tell me the size of the gear (final gear?).
 
21 - 40 of 44 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top