Possible solution to battery connect spark??

[Ub Hauled]

Exactly

[Boatman]

So, is it possible that when there is no load there is no spark right? What if on a HV setup you used a switch heavy duty of course that could be off in line of the neg. side and when turned on no spark, no damage, no worries?

[Drag Boat Bob]

http://hyperphysics.phy-astr.gsu.edu...ic/capchg.html

Yep, I rest my case.

Charging current is momentary and not enough to erode the contacts at something less than 25v (no heat generated) .

That is of course, unless you do it 100,000 times.

[Drag Boat Bob]

So, is it possible that when there is no load there is no spark right? What if on a HV setup you used a switch heavy duty of course that could be off in line of the neg. side and when turned on no spark, no damage, no worries?

Any dissimilar voltage source (ie: energized vs. non-energized) will cause a spark. This occurs to equalize the voltage between the objects. However the time/current involved will determine the affect on the objects.

Think of it this way. You move your feet across the carpet with your socks on. You grab the door knob and 'whack' a voltage spark occurs. It is high in voltage and low in current. Your finger does not get burned (current), but you feel the jolt of the voltage.

[domwilson]

Actually it can even at lower voltages. It all depends on the current passing thru the circuit. You can try that with a car battery. Connect two pieces of wire one to the positive and the other to a negative. Then momentarily touch the two wires. You'll see how it burns the contacting surfaces. But that's not relevant to the topic. Some people don't like the spark because of one reason or another. Others don't care. It's all about choices for each individual.

[graill]

I would comment on a couple comments but they might be taken as attacks so i will reply to the OP and the other person asking for the best way or one alternative.

To the folks asking about the what to do. Use a resistor inline for the appropriate voltage and know how to use it or get an esc with anti spark tech.

Using a cap charging spark to indicate whether your esc has bad caps or not is foolish at best, use a multi meter to check your cap during your maintenance interval, thats what it is for.

A spark is indeed the caps pulling amps so fast they jump your plug gap as you get them close together, its not the voltage that does the damage, and the spark (amps) will eventually slam the caps enough to cause failure and erode connectors eventually, and it wont take 100,000 times. Resistors are installed in most high amp electrical circuits today to prevent this fast draw, its called anti spark tech and there is a reason for it.

OP you connect ground last and disconnect it first, thats the proper way to connect any electrical circuit. Indeed a ground will always eat a positive up to the point of load.

And as a couple folks pointed out, in the end do what you want, its your money and equip after all.

[sailr]

I don't think we are afraid of the spark, it is the destruction of the connectors! Frustrating if it happens just as you're plugging in for a race and you can't complete the connection due to the burnt connector. I agree it's easier and cheaper to replace connectors than esc's BUT...

The OP's theory doesn't hold water. I get a charge out of reading the demands for "no spark" when connecting the power wires to the ESC. Why is everyone so afraid of a little noise and light? It is the sparking of this connection that signifies the caps are functioning as intended to protect the ESC. Without the caps functioning the ESC will soon fail. If your ESC doesn't spark, you know to replace the caps. It is a method to prevent ESC failure. With care during the connecting process the spark won't damage your connectors, but even if they are damaged, connectors are a lot easier and cheaper to replace than a damaged ESC....



.

[sailr]

Makes sense to me. If you plug in once, you have charged the caps. If you unplug and then plug in again (without running the caps down first) then very little spark. Doing it this way is not a true test.

So Dom, what da hell does that mean in English?!

[sailr]

YEP! That's what I always do. Just a light quick 'tap' of the edges to dispel the original BIG spark and then plug in the rest of the way. It still erodes the end of the male connector which can make it tough to plug them in all the way.

yes, touch the ends of the connectors first before sliding the bodies together, that way the spark erodes the ends and not the outer surface that passes current in normal use when they are fully mated.

[sailr]

Theory is great but you oughta see my connectors from just 4S setups...only 14.8V!

Yep, I rest my case.

Charging current is momentary and not enough to erode the contacts at something less than 25v (no heat generated) .

That is of course, unless you do it 100,000 times.

[sailr]

Somebody posted on OSE that they made up a temporary inline resistor. They use it for the initial plugin...charge the caps...and then take it out and plug in the normal connectors. Little or no spark. Sounds like a plan! I'm still cornfused about the right size resistor to get though!

I would comment on a couple comments but they might be taken as attacks so i will reply to the OP and the other person asking for the best way or one alternative.

To the folks asking about the what to do. Use a resistor inline for the appropriate voltage and know how to use it or get an esc with anti spark tech.

Using a cap charging spark to indicate whether your esc has bad caps or not is foolish at best, use a multi meter to check your cap during your maintenance interval, thats what it is for.

A spark is indeed the caps pulling amps so fast they jump your plug gap as you get them close together, its not the voltage that does the damage, and the spark (amps) will eventually slam the caps enough to cause failure and erode connectors eventually, and it wont take 100,000 times. Resistors are installed in most high amp electrical circuits today to prevent this fast draw, its called anti spark tech and there is a reason for it.

OP you connect ground last and disconnect it first, thats the proper way to connect any electrical circuit. Indeed a ground will always eat a positive up to the point of load.

And as a couple folks pointed out, in the end do what you want, its your money and equip after all.

[Drag Boat Bob]

Theory is great but you oughta see my connectors from just 4S setups...only 14.8V!

I too get a spark when connecting at 14.8v. I make the connection quickly and do not hesitate. I have not experienced any contact degradation.

Maybe I'm just fast... lol...

I worry more about the voltage spike to the esc than contact wear.

[bustitup]

The OP's theory doesn't hold water. I get a charge out of reading the demands for "no spark" when connecting the power wires to the ESC. Why is everyone so afraid of a little noise and light? It is the sparking of this connection that signifies the caps are functioning as intended to protect the ESC. Without the caps functioning the ESC will soon fail. If your ESC doesn't spark, you know to replace the caps. It is a method to prevent ESC failure. With care during the connecting process the spark won't damage your connectors, but even if they are damaged, connectors are a lot easier and cheaper to replace than a damaged ESC....



.

I will add that this is exactley what tech will tell you at Castle and Joe Ford from castle has mentioned this a number of times in these forums

[bustitup]

Somebody posted on OSE that they made up a temporary inline resistor. They use it for the initial plugin...charge the caps...and then take it out and plug in the normal connectors. Little or no spark. Sounds like a plan! I'm still cornfused about the right size resistor to get though!

and I'm pretty sure for a 240HV they suggested 1 ohm 5watts resister

[NitroVal]

I dont get why they havent made a switch to handle this yet..