Volthium - Lithium BIM225 Battery Charger
Volthium - Lithium BIM225 Battery Charger
Par Volthium

Volthium - Lithium BIM225 Battery Charger

Regular price$199.98
  • In stock, ready to ship
  • Inventory on the way


  • Supports continuous currents of 225 Amps
  • Monitors battery voltage over long periods
  • Connects two battery systems together


The Precision Circuits lithium battery charge relay (Li-BIM), product code 00-10041-260, is an intelligent battery isolator that manages the house battery and the engine/starter battery in an RV, camper, or fifth-wheel trailer. This prevents loads from one system from discharging both. It also connects the two battery systems together during charging. Both batteries are charged if either is being charged: The house battery is charged while driving and the engine battery is charged when plugged into shore power at a campsite.

The Li-BIM is based on a microprocessor and is much smarter than your average battery isolator. It monitors battery voltage over long periods and does not rely solely on voltage. The voltage settings of the Li-BIM are such that it works well with a lead-acid engine battery and a lithium-ion house battery (although a lead-acid house battery also works).

The Li-BIM monitors the voltage of the lead-acid engine battery and the lithium-ion house battery over long periods. If it detects a charging voltage, it connects the two batteries together. It will charge the house battery from the alternator, as well as the engine battery from shore power, depending on where it detects a charging voltage. It will disconnect the house battery if the alternator exceeds 14.4 volts to prevent overcharging the lithium-ion batteries. The Li-BIM charges the house battery for 15 minutes when it detects a charging voltage on the engine side, then disconnects it for 15 minutes to allow the alternator to cool, and repeats this cycle until the house battery is full.

For the engine battery, the Li-BIM will monitor the battery voltages on both sides and charge from the house battery if it sees a charging voltage and less than 12.6 volts on the engine side. It will charge this way for a maximum of one hour, then disconnect again to take another voltage reading.

The ignition terminal of the Li-BIM is used to detect when the engine is running (and it can potentially charge from the engine to the house battery). If the ignition is turned off, the Li-BIM disconnects immediately. The "dash switch" terminal is optional. If connected to ground or the positive battery terminal (both work, whichever is easier to wire), the Li-BIM will connect immediately, regardless of battery voltage. It is intended to be used with a momentary switch to temporarily connect the house battery and engine battery together (for example, to start the engine if the engine battery is low). It disconnects as soon as the switch is released.

It consumes no current in on or off state. It supports continuous currents of 225 Amps and 1,200 Amps for 30 seconds. Please note that the datasheet (in the "documents" section) is incorrect; it indicates 160A for this version of the Li-BIM, while the unit is actually designed for 225A continuous.

View Manual