Connecting a ElCon charger

You MUST provide a way for the BMS to shut down the charger, DIRECTLY!

Just because you have a BMS on board, don't think that your pack is protected.
Until you allow the BMS to shut down the charger, your pack IS NOT PROTECTED!

You MUST make sure that:

  • When the BMS says "stop charging" the chargers does stop charging
  • When the BMS says "restart charging" the chargers does restart charging.
  • The BMS is powered whenever the vehicle is plugged in the wall (whether or not the charger is on at the time)


The BMS must be powered whenever the vehicle is plugged in the wall to protect the pack during charging, and to perform balancing even if the charger is off at the moment.

If there is any current in or out of the pack, yet the BMS is off, your pack IS NOT PROTECTED!

Near the end of charge, the BMS will turn the charger on and off, continuously, for a while.
You MUST allow the BMS to do that; otherwise, the BMS will not be able to balance the pack.

Just follow the instruction below, exactly, and you'll be fine.

The ElCon charger hardware must be a current revision (its control connector must be made of black plastic with blue cover, and not a chrome DIN connector), and the charger must be programmed by ElCon with Algorithm 500-599 series (as indicated by a small, long white programming label near the serial number label marked such as "Alg 512 288V2K5W ...").

The ElCon charger is smart, and is great for packs used without a BMS that are already top balanced.
However, its smarts get in the way of the BMS getting the job done.
Unfortunately, ElCon does not offer a plain CCCV charger, which would be ideal.
We have analized the ElCon profiles, and the least problematic is profile 520.
Specify the following:

  • Profile: 520
  • Max voltage, V4: max cell voltage x number of cells in series
    • e.g.: for 100 LiFePO4 cells in series: v4 = 100 * 3.6 = 360 V
  • All others voltages: don't care
  • All currents: max available for that charger

You MUST use a fuse ("Charger fuse"), between the pack and the Lithiumate Lite master's "Charger current sensor" input, as close as possible to the battery.

The fuse must rated for DC operation, rated for the full pack voltage, and rated for the charger current (30 A maximum, else you may blow up the Lithiumate Lite's charger sensor input).

This charger allows both control options: AC power and DC control

With this option, the BMS master controls the charger through a contactor to switch the charger's AC power on and off.

Schematic diagram
AC power switching

A note about AC relays

You need a relay (or contactor) whose contacts are rated for BOTH the line voltage (i.e.: 125 Vac or 250 Vac), and for the current (i.e.: 15 A, or whatever the maximum input current of the charger is).
Just because a relay is rated for 30 A, it does not mean that it can switch the AC power.

With this option, the BMS master controls the charger through an external relay that disables or enables the charger.

Controlling the charger's enable input requires a relay for isolation.

Schematic diagram
Control input, external relay

Control relay information

Relays can be "signal" or "power".

  • "Power" relays can carry a lot of current, but must be used with at least 1 A, or their contacts will quickly oxidize
  • "Signal" relays do not need to be operated at minimum current, but are not available with quick-connect tabs.

In this application we need a "signal" relay, because we ask it to switch a very low current.

A typical automotive "cube" relay is nice because it is easy to mount and has quick-connect tabs. However, it only comes in "power" type.

We know that, in all likelihood, you will use a "cube" relay, which is not ideal for this application. So, we offer a workaround: add a capacitor (100 nF, 25V or more, any type) across the contacts of the relay; when the relay contacts are open, the charger will place a voltage across the capacitor, charging it; when the BMS master first energizes the relay, the contacts will close, quickly discharging the capacitor; the resulting pulse of current will clean the contacts, ensuring long life for the relay.

If you do use a signal relay, the capacitor is not required, because the relay contacts remain clean even with no current.

Cube relay
Cube auto relay

With this option, the BMS master controls the charger directly through an internal relay that disables or enables the charger.


The internal relay in the BMS master is not polarized: you can interchange pins 1 and 2.

Schematic diagram
Control input, internal relay


By reading this page you acknowledge that you understand that this application note is just a suggestion, and that you will not hold Elithion responsible for its accuracy or appropriateness in you application, and that Elithion is not responsible for the fact that other manufacturers change their products in a way that may make these suggestions no longer applicable.
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Page published on: Jul 19 2013.      Installation manual