Prevent Sparks when connecting ping

[my.motion]

Hi Team,

I have a ping battery with 2 way connector on the power source lead and same connector from controller power source. Everytime, when connecting the connectors /joints I can hear the metal contacts on the connecor generating a spark. These sparks create chipping and black marks on the metal contacts. Does this mean there is something wrong with my connections? How can I prevent these sparks everytime I connect the battery to bike please?



You help on this is highly appreciated.

Thanking you in advance


Motion

 

[jerrysimon]

Put a switch in the controller side of the circuit ?

Although there are mixed views about this. There is also a post here somewhere about using an additonal protection circuit with the switch to get over these concerns.

Regards

Jerry

 

[my.motion]

Thanks Jerry, sometimes the switch side also sparks when you turn the key to ON. Just wondering if there is a way to prevent these sparks as well

 

[NRG]

Classic way to stop a switch arcing over is to place a 'condenser' (a very old term for a capacitor) accross the switch contacts. A 0.1uF ceramic disc cap or a plastic film cap would reduce the spark.

Or you could use one of these from Maplins: Contact Suppressor : Suppression : Maplin

 

[andyh2]

On my Ping battery set up I had worrying sparking at first. I wired mine up;

battery - fuse - switch - anderson pole battery connectors - controller.

No sparking now.

 

[my.motion]

Thanks NRG, pardon my ignorance but where and how will this device connect

thnx

 

[NRG]

Directly accross the positive switch contacts as if you where trying to short the switch out...

 

[Leesome]

If short (get it?) of funds could try engaging the brake, if that is your brakes disconnect the motor controller. Possible controller caps (capacitors) are absorbing voltage, this in-rush creates a spark on the neutral? Satis melt connector contacts. Best solution is a switch, quality one should not cause any issue. Or heavier duty connectors?

 

[onmebike]

Any switch used must be capable of handling at the very least, the maximum amps drawn by the motor and I suggest a double pole switch that cuts both positive and negative line's to reduce sparking.
What is a concern is the fact your getting the sparking with the key switch turned off, when the circuit should be isolated?

Where is the key switch, on the battery or controller? If on the battery, the connector shouldn't be live when you connect the battery, so no spark's. This may indicate a faulty key switch.
If the key switch is on the controller, the circuit should be isolated when the key switch is off, so again no spark's when connecting battery? This may indicate a faulty switch thats arcing inside, a faulty component such as a leaking capacitor or possibly a short circuit.
Does the system run okay once powered and have you ever connected the battery the wrong way round, even for a split second.

 

[emissions-free]

I've also had this problem and I think that even if your connectors are correctly rated they will still get damaged over time with the big in-rush of current. I was connecting 2 big 35A controllers to a 48V battery and the spark was massive and very quickly damaged the contacts quite badly, pretty much welded them together actually and made them very difficult to mate together. The way I would do it is to try to just touch the contacts together momentarily a couple of times and this will give the caps a chance to charge without putting too much strain on the connectors. A suitable rated switch is probably the best solution. I was also toying with the idea of having a 2nd smaller plug connected in parallel with a series resistance that could be connected first and which allowed the capacitors to charge more slowly over a few seconds before connecting the main power plug. If the resistor is suitable sized and rated the secondary plug and cables do not need to be particularly big. This would avoid any big sparks.

 

[Herb]

I use a 32A MCB to switch the current on my 36V Ping battery.

This also acts as a fuse to protect the battery (I believe the battery BMS will also act as protection in the event of a short circuit).

Herb

 

[onmebike]

I've also had this problem and I think that even if your connectors are correctly rated they will still get damaged over time with the big in-rush of current. I was connecting 2 big 35A controllers to a 48V battery and the spark was massive and very quickly damaged the contacts quite badly, pretty much welded them together actually and made them very difficult to mate together. The way I would do it is to try to just touch the contacts together momentarily a couple of times and this will give the caps a chance to charge without putting too much strain on the connectors. A suitable rated switch is probably the best solution. I was also toying with the idea of having a 2nd smaller plug connected in parallel with a series resistance that could be connected first and which allowed the capacitors to charge more slowly over a few seconds before connecting the main power plug. If the resistor is suitable sized and rated the secondary plug and cables do not need to be particularly big. This would avoid any big sparks.

Hi Emissions-free, I can understand the sparking if connecting directly to the controllers without the key switch isolating the circuit, the capacitors would charge up.
But in this case there is a key switch which I'm assuming is turned off while connecting the battery. There shouldn't be any load to cause the spark's.
My first concern would be the key switch, if faulty or already burn't it may not be completely isolating the circuit when turned off.

 

[emissions-free]

Hi Emissions-free, I can understand the sparking if connecting directly to the controllers without the key switch isolating the circuit, the capacitors would charge up.
But in this case there is a key switch which I'm assuming is turned off while connecting the battery. There shouldn't be any load to cause the spark's.
My first concern would be the key switch, if faulty or already burn't it may not be completely isolating the circuit when turned off.

Agreed that is a bit strange. It does sound like there's something amiss with your switch for sure. I've used domestic circuit breakers before (not MCB as above which is probably better as it would also trip in the vent of a fault)and they worked no problem with higher current than you are likely to be pulling

 

[my.motion]

Hi All

I haven't connected a switch yet, but the sparking only happens when I first connect the connectors. I will try putting a switch and report back

thanks

 

[daniel.weck]

You could try this technique:

http://www.pedelecs.co.uk/forum/electric-bicycles/5098-building-small-a123-battery-pack-9.html?highlight=spark#post67644

...although I'm sure that the advice already given in this discussion thread leads to simpler, albeit equally effective solutions.

Cheers, Dan