Can I use Lithium batteries with the Watt&Sea converter ?

Yes, and there a few point of attention.

1/ Modification of the converter settings

Converter settings can be modified, by using the Watt&Sea mobile app for 2019+ devices with bluetooth. To be able to change the settings, you will need to restart the converter, by disconnecting/reconnecting it from the batteries. It has to be done with the hydrogenerator stopped.

After restart, you have access for ~5 minutes to settings modification.

For older converter without bluetooth, you can change the settings using a computer software, available here.

a) Check the end-charge voltage settings

Check that the Absorption and Floating voltage values of your batteries datasheet are the same than the converter settings by default. If not : change the Absorption and Floating voltage values.

b) Modify the Reset-to-Abs Voltage value and ABS cycle duration

The lithium batteries keep a higher voltage value at low SOC than the lead/AGM/Gel batteries. Therefor, it is necessary to adjust the Reset-to-Abs Voltage value and ABS cycle duration :

• Set the ABS cycle duration to 720min
• Increase the Reset-To-Abs Voltage, to allow the converter to start a new charge cycle sooner.   Follow the battery data sheet.

c) Disable the battery auto-detection loop

With lithium batteries installation we recommend to force battery voltage autodetection either to 12V or 24V :

Battery voltage :

0 = autodetect 12/24

1 = force 12V

2 = force 24V

( 3 = force 48V )

2/ Optionnal : Wire a stop relay

Some Lithium Battery Management Systems (BMS) like Mastervolt / Victron require to be able to stop production sources, for safety reason. Then, a relay has to be used (available in « accessories ») to short-circuit the generator when you’d like to stop the production.

This relay has to be used associated with a braking resistor to dissipate the energy produced by the  generator and to prevent the generator from overheating.