Vedder sparkswitch 25$ chaka's revision

I threw some copper on it just as you mentioned. Each cell is wired with a fusible link that should be blown. Best way to do this is to short out the poles…

At 518 volts and 60 Amps, my booster cable copper ends vaporised. I just ripped the covers off in the end, just as quick, not so dramatic.

EDIT And this is the fruit of labor.

3 Likes

why should the fuse wires melt when you touch the positive and negative of the entire pack? The current going through a single cell should not be even close to melting the wire.

:joy::joy::joy::joy::joy::joy: LOL! That made my day! Hope there´s nothing damaged… but yeah should work fine, if the fuse wire really protects the cell, that they don´t suffer under a too high current

Nothing wrong with the cells, I pulled 38 tonight, all fine. My booster cable, both -'s are vaporised. Shudda used welding cable without 1 end. I’m cutting a snip from the video and will up it soon.

In the meantime, here are 2 other guys dead shorting a pack as well.

2 Likes

Looking to buy one of these switches in September for a 7s6p INR 18650 pack (20A continuous from each cell, 2500mah for each cel) setup. Will this be fine (don’t want any sparks on my first build) - I have had enough magic smoke and am looking to avoid it!

Yes it can absolutely handle that pack all sparks will be gone and everything gets powered by the push of a button.

Your best indicator of compatibility with any battery pack is the BMS that is in the pack you are building or considering. The ASW is rated at 30A, the BMS must not exceed 30 Amp output. This has nothing to do with the cells capacity as any Parallel group may exceed the 30 Amp capability of the ASW.

Volts increase in the Series, Amps stay the same. Volts stay the same in Parallel, Amps increase. You have S,20A*6P=120A is the unregulated total output (Not peak output).

In Theory: If your battery pack BMS is delivering 25V 60A, you will need 2 of these in Parallel to not burn them up. If your battery pack BMS is delivering 25V 30A, you will need 1 of these. If your battery pack does not have a BATTERY MANAGEMENT SYSTEM, the total PEAK output is what you will be putting through the circuit, that will be over 120 Amps. The final determining factor is what’s the total draw of your system, if all the system can take is 5 Amps, well then you’re fine, if your system can eat 60 Amps, but is throttled by a BMS @ 30 Amps, your marginal, but within the rated specs. If you are running a motor that eats 60A nom and 90A peak, and you have a battery pack at 25V 120A without a BMS…TOAST, Well Done Toast.

I was planning on using the VESC in my setup to limit the current and do not expect too much cell voltage drift (I will have 6 cells in parallel then connected in series 7 times - each lot of 6 cells with have the same voltage) and I will be balance charging them. I have decided to go for a (http://www.screwfix.com/p/schneider-electric-easy9-50a-single-pole-type-b-mcb/9688p) as they are relatively cheap, local and I will set up my VESC so that the current cannot go above 45A. Please let me know if you think my plan is crazy and that I am asking for a fire!

Yes you are.

I don’t really understand as I will also be using a Low Voltage Alarm Buzzer Indicator Meter (the alarm used on lipos which are triggered at 3.3V). These alarms constantly check the voltage of all the cells you are using in series and sound an alarm if they go under 3.3V - the equivalent of 1.8Ah used of total 2.25ah under 5A load per cell - 30A at 29.4V in total. So I won’t be draining my cells excessively - no fire risk and I will be charging with a balance charger (they won’t get overcharged) - no fire risk. Where is the fire risk if I have set my vesc to limit the current output?

Bump still have a bunch available.

If you don’t use a fuse do you simply connect the 2 pads?

Could you provide a labeled picture of the finished product. Trying to visualize where all the wires go.

Yes you connect the two pads and if you bought one of my switches the visualized image is on the back of it.

im interested in purchasing one. are they still available for sale?

perhaps +1… but did I read right that the amp limit on them are 30A?

@Shogu12 is not around these days, a GB went tits up and he’s gone awol