Prevent spark/damage when connecting battery

[ytwytw]

Hey guys

I am trying to figure out the way to prevent spark and damage to inverter/charger when connecting to the battery.

I do know Will showed using a wirewound resistor to pre-charge the capacitor so that no spark and damage will happen.

however, I have very difficult time to find a 25ohm or higher wirewound resistor, only thing in Canadian Tire is a 6ohm 10W wirewound resistor, and it does produce sparks when i make the connection.

So, other than wirewound resistor, is there any other alternatives?

I have some DC breakers (100Amp, 63Amp and 40Amp) around, would those actually help?

Thanks

 

[SolarRat]

Put 4 of those 6ohm resistors in series and it'll be 24ohm.

I use whatever is handy, even tiny 1/4w resistors seem to work for most circuits (if you're only charging the caps and no loads are on). Got any broken electronics you can remove some resisters from?

You may also be able to use something like a lightbulb in a pinch.

 

[cass3825]

An automotive test probe (old incandescent style) works great, or any automotive lamp (turn signal, brake/tail, etc) will work too. Super cheap!

 

[Refinished]

Someone here had the interesting idea of using a standard light bulb and that's working for me.

 

[ytwytw]

oh yeah I do have those incandescent lights as well

Just tried and it does work perfectly

Thanks guys

 

[JoeHam]

I used one of these:

Amazon.com: YiePhiot 2PCS 50W 25 Ohm Resistor Aluminum Case Wirewound Chassis Mounted Compatible with Ring Doorbell, Nest Hello Doorbell, SkyBell Doorbell Etc : Industrial & Scientific

Amazon.com: YiePhiot 2PCS 50W 25 Ohm Resistor Aluminum Case Wirewound Chassis Mounted Compatible with Ring Doorbell, Nest Hello Doorbell, SkyBell Doorbell Etc : Industrial & Scientific

www.amazon.com

In case you run out of incandescent bulbs!