20 Amp Liftgate Battery Charger | LittleFuse LGBC – 880209

The 20 Amp LittelFuse Liftgate Battery Charger is designed to boost the voltage of the battery on the trailer when the trailer battery is mounted several feet away from the tow vehicles alternator.

This charges the trailer mounted battery much faster while the trailer is being pulled down the road. It even works while the tow vehicle is turned off.


How the Liftgate Charger Charges Batteries:

Here is a brief explanation of how the lift gate battery charger charges batteries. When the batteries are
dead, the charger will supply 20A to 35A depending on the model. Once the batteries get some charge
back in them, the charging voltage will be between 13.9v and 15.4v for AGM and between 14.4v and
15.8v for Flooded Lead Acid batteries. Once the batteries are almost fully charged, then a charging
voltage of 14.4-14.5 will be applied till they are completely charged.
Keep in mind, we lower output current if input voltage is too low. This protects the wiring and

We also adjust for battery temperature to keep from boiling the batteries which is why there is a range
of voltages when charging rather than a standard 14.2v.
When the battery extender is turned on, the lift gate battery charger will continue to charge even after
the vehicle is turned off. It has a cutoff voltage of 12.5v to ensure the user will always be able to start
the vehicle. If the extender is turned off, the lift gate battery charger will stop charging at about the
same time as the vehicle is turned off.

As far as input cables, we use a 10 AWG for the 20A version and 8 AWG for the 35A version. However,
the input cable size on the customer’s truck isn’t a huge deal. Clearly, the bigger the cable the better it
will work, but our unit dynamically adjusts output current based on input voltage. As you know,
customers use a lot of different cable sizes on the connectors, but our device will never burn up a
harness. If a small cable is used, there is a higher voltage drop from the vehicle batteries to the Liftgate
battery charger than if they were using a larger cable. We are able to sense that voltage drop and adjust
output current to make sure things don’t get too hot. Keep in mind, this is a dynamic current adjustment
based on input voltage, not a temperature sensor.

Now, what does all of this mean? Basically, we will never hinder the situation on the trailer. We can only make it better!

Why is LittleFuse better? See Comparison and Advantages Chart here.



  • Part No. 880209
  • Input Voltage Range: +9.5 to +16 Vdc
  • Max Output Current: 20 Amps
  • Storage Temperature Range: -55 C to +125 C
  • Ambient Air Operating Temperature: -40 C to +85 C
  • Dimensions: 143 x 192 x 60 mm
  • Weight: 8.8 lb (4 kg)
  • Compliance: FMVSS 121; SAE J227; TMC RP141
  • Ingress (IP) Rating: IP67 and IP69K



Recommended Setup:

Liftgate Charging System Documents: