Does the lift retrofit kit drain the battery, does it draw current when parked?
The kit draws meaningful current only while moving; the LFT20 averages 10A. To break the line when parked, feed the supply from the ignition through a relay.
The kit draws meaningful current only while it is moving: the LFT20 draws 10A on average and a typical lifting cycle lasts seconds. The motor does not run unless the switch is pressed. Connected straight to the battery through a fuse, the line stays live; that is why, for long periods parked, the supply should be connected to the ignition signal through a relay.
Running current and standby current are different things
- Running current: The LFT20 draws 10A on average and a typical lifting cycle lasts seconds. With the engine running the alternator covers this comfortably; with the engine off, cycles one after another pull the battery down.
- Standby: The LFT20 has no board, processor or sensor, so there is nothing electronic in it consuming while it sits. The LFT54 has an embedded control board; the manufacturer has not declared a numerical standby current value.
Where standby consumption on a vehicle comes from in general can be found in the entry on standby current. On a tractor the largest standby load is usually not the kit but the radio, the tracker and the lighting added afterwards.
How to break the line while parked
On tractors that will stand unused for a long time, the safest approach is to connect the supply line to the ignition signal through a relay. The kit is then completely dead with the ignition off, and pressing the switch by accident comes to nothing. You will find the wiring of the relay arrangement, and why the power line is still run from the battery, under battery supply or ignition supply. If no relay is to be used, at least put the fuse close to the battery terminal and throw the battery isolator before parking for the season.
When choosing a relay it is enough for the contact to carry the running current of the kit comfortably; since the coil is fed from the ignition line, it is driven with thin wire. If you are going to leave the relay outside the cab, fix it somewhere watertight with the connectors facing downwards.
The use that really tires the battery
What tires the battery is not the presence of the kit but movements repeated with the engine stopped. One lifting cycle is short, but a large number of cycles one after another adds up to a serious load and can take the battery into a deep discharge. Why that is particularly harmful for a lead-acid battery is explained in the entry on deep discharge. Do adjustment and trial work with the engine running wherever you can. On tractors that stand a long time over winter the self-discharge of the battery enters the picture too; even with the kit completely out of circuit, the battery falls in time.
What to look at before blaming the kit
On a tractor with a weak battery, the mechanism moving slowly is not a kit fault. Check the following in order:
- Battery voltage and how clean the terminal posts are.
- Whether the chassis connection has been taken from a point cleaned back to bare metal.
- Whether the charging voltage holds the expected band with the engine running; the detail is under alternator charging voltage.
- Whether the supply cross section and the position of the fuse are suitable.
- Oxidation on the switch and the wire terminals; a single high-resistance terminal slows the movement even with a healthy battery.
What to do in practice
Feed the kit through an ignition-controlled relay at the installation stage; that one decision removes both the parking problem and the risk of it being operated by accident. If you are going to leave the tractor standing a long time, leave the battery fully charged. Do the first trial of the season with the engine running and the linkage empty: trials made loaded with the engine off waste the battery and lead you to mistake slow movement for a kit fault.
The full topic: Converting a tractor hydraulic lever to electronic control