markz
100 TW
I was using a loose 150 ohm 10% resistor, even with a 1 to 2 second delay from removing the resistor to plugging in the battery wire, it did not spark.
Big spark when connecting battery to bike
- Thread starter andrenoites
- Start date
DrkAngel
1 GW
See also - Simple-Cheap Pre-charge Switch
ElectricGod
10 MW
Old thread...I know I know...LOL
I use contactors in my EV's. Battery power is on one side of the contactor and the EV electrical system is on the other side. in parallel with the contactor power posts is a 1K 10 watt ceramic resistor. Open the contactor and the resistor can precharge the system. AT 10 watts, that resistor can take just about anything you throw at it! Close the contactor and the resistor is bypassed. When ever I need to disconnect power I just open the contactor and then mess with the batteries at will. Once I am all done and plug in the batteries again, they are already connected to the precharge resistor. It becomes a very simple thing to precharge...turn off the contactor, plug in the batteries, turn on the contactor. There is no need for lame anti-spark connectors or a jumper or switch to close once the batteries are connected for precharging. It just happens automatically. Plug in, close the contactor and go.
These contactors are inexpensive and relatively compact. They make and break at 200 amps and come in lower ratings too. Did I mention it costs $6? That and a $1 resistor and you are set for life. You will never burn it out or wonder if it is still working. I know from personal experience that 130 volts is no problem. Who cares that it was made for your RV battery bank!
http://www.ebay.com/itm/200A-Car-Truck-12V-24V-Battery-Isolator-Disconnect-Cut-OFF-Power-Kill-Switch-/332163596663?epid=2108905871&hash=item4d567e4177:g:0UsAAOSw4~VZgo1S&vxp=mtr
Here is one of my recent builds with a contactor in it with precharge resistor on it.
I use contactors in my EV's. Battery power is on one side of the contactor and the EV electrical system is on the other side. in parallel with the contactor power posts is a 1K 10 watt ceramic resistor. Open the contactor and the resistor can precharge the system. AT 10 watts, that resistor can take just about anything you throw at it! Close the contactor and the resistor is bypassed. When ever I need to disconnect power I just open the contactor and then mess with the batteries at will. Once I am all done and plug in the batteries again, they are already connected to the precharge resistor. It becomes a very simple thing to precharge...turn off the contactor, plug in the batteries, turn on the contactor. There is no need for lame anti-spark connectors or a jumper or switch to close once the batteries are connected for precharging. It just happens automatically. Plug in, close the contactor and go.
These contactors are inexpensive and relatively compact. They make and break at 200 amps and come in lower ratings too. Did I mention it costs $6? That and a $1 resistor and you are set for life. You will never burn it out or wonder if it is still working. I know from personal experience that 130 volts is no problem. Who cares that it was made for your RV battery bank!
http://www.ebay.com/itm/200A-Car-Truck-12V-24V-Battery-Isolator-Disconnect-Cut-OFF-Power-Kill-Switch-/332163596663?epid=2108905871&hash=item4d567e4177:g:0UsAAOSw4~VZgo1S&vxp=mtr
Here is one of my recent builds with a contactor in it with precharge resistor on it.
