[Ziggythewiz]

the specification said:

What specification? The controller?

What kind of fuse(s) are you looking at?

 

[rico12410]

yes, that is the spec for the controller..

what kind of fuse(s)?
please recomend.. i am in the dark for the many kind of fuses..
i thought, I just need to 'see' how big or small (the spec) of the fuse i need?

What specification? The controller?

What kind of fuse(s) are you looking at?

 

[Ziggythewiz]

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.

 

[rico12410]

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.

 

[Ziggythewiz]

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.

 

[rico12410]

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

 

[rico12410]

thank you ziggythewiz for your insight..
I will search and try your approach, start with 150A fuse

thank you

 

[PStechPaul]

Hooray!

I think your final schematic is OK. Good luck!

 

[Ziggythewiz]

Is that charger specifically designed to charge 4 batts in parallel that are also connected in series? If not they're all shorted.

 

[PStechPaul]

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.

 

[rico12410]

thank you friends!
You guys rock and save my day
To simplify I am not using switches and charge the four batteries with only one charger.

[http://www.freeimagehosting.net/qo7uc]

I hope this can be a final scheme?

thanks again guys

 

[Ziggythewiz]

Looks good. One charger at the right voltage is the way to go.

 

[rico12410]

thank youu

 

[rico12410]

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.

 

[Ziggythewiz]

Re: update

How much does your whole build weigh, and what is the controller rated for?

 

[rico12410]

Hi Ziggy,

I haven't find a DIY way to weight the vehicle.
I am guessing, is about 750 kg?

the controler is 48V rated for 600A

thx

 

[Ziggythewiz]

How much power does it take to go up that hill? What speed? Gear? How many amps can the batts put out?

My bug's less than twice the weight of your bemo but has nearly triple the power and doesn't do great on a hill.

 

[rico12410]

Hello Ziggy,

The batteries put out 100Ah..

oo.. perhaps my bemo need bigger power (motor + controller)?

 

[Ziggythewiz]

A battery can have a capacity of 100AH, but it's max current will be in Amps. Do you have an ammeter in the car?

Does your bemo have a transmission? If so, what kind of gearing options do you have?

 

[rico12410]

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?).