Wee-Pre Charge

Avoid sparks and contact current surges!

When connecting a battery to a load with a capacitive input for the first time, a connection current surge occurs when the load capacity is charged to the battery voltage.
With large batteries (with low internal resistance, especially lithium batteries) and heavy loads (with large capacitors at the input/output), the contact current surge can easily reach 1000 A.

It "sparks" when connecting. This is not ideal for the service life of the capacitors, and contact burn-off can also occur at the contact point. This material burn-off can lead to injuries (eyes) and damages the connection point. This is particularly the case with large inverters & chargers above 24V.


To avoid this contact / connection current surge, the device should be "pre-charged" via a resistor before connecting it to the battery.


With the WeePrecharge, we have created a pre-charging resistor with which sparking and the contact current surge can be avoided.


This pre-charging resistor is not intended for pre-charging with main switches.
If you want to pre-charge with a main switch, this must be permanently installed via a push-button.
Pre-charging units are available for automatic main switches. Please contact us for more information.