This item is free with the purchase of a Volthium battery (just add it to your cart, or ask us).
The BMS (Battery management System) build into lithium-ion batteries has hard limits for the amount of current it will allow. This can result in nuisance tripping, causing the battery to get switched off, when a (large) inverter is connected to the battery. The reason is that inverters have capacitors on their DC input that can draw very large currents to charge up. Once they are charged there is no issue, and the battery only has to supply the much lower running current for the inverter.
The (free) Volthium 10 Ohm 10 Watt resistor is intended for use to charge up the input capacitors of a (large) inverter. This avoids tripping the BMS when the inverter is wired to the battery.