In general, the subject matter of the disclosure relates to an orientation agnostic battery placement device. Connecting a battery in a reversed polarity configuration may cause the battery-powered electronic devices to not work or in some cases may even cause damage to the device itself. The disclosed orientation agnostic battery placement device includes a latch relay device that includes a first latch switch that electrically connects the first and second terminals of a battery compartment to the positive and negative electrical power connections of a load circuitry associated with the battery-powered electronic device respectively when the battery received within the battery compartment is in a first orientation and a second switch that electrically connects the first and second terminals of the battery compartment to the negative and positive electrical power connections of the load circuitry respectively when the battery received within the battery compartment is in a second orientation.

Methods and devices for wired charging and communication with a wearable device are described. In one embodiment, a symmetrical contact interface comprises a first contact pad and a second contact pad, and particular wired circuitry is coupled to the first and second contact pad to enable charging as well as receive and transmit communications via the contact pads as part of various device states.

A vehicle emergency start device includes a switch module, a reverse connection protection module, an emergency start switch and an output module. The switch module is respectively connected to the emergency start power supply of the vehicle and the output module, and the reverse connection protection module is used for reverse connection detection and/or load detection; and the emergency start switch is connected to the switch module.

Improved systems and methods for balancing a state of charge (SOC) of a plurality of batteries are disclosed. For example, a system may include multiple battery strings connected in parallel to one another through a common bus. Each battery string may include a power converter and multiple battery modules connected in series. The power converter may be configured to regulate the combined power output of the battery modules. Each battery module may include multiple relays that may be controlled to discharge, charge, and/or bypass that battery module. Collectively, the power converters of the battery strings and the relays of the battery modules may be controlled to balance the battery strings with one another and to balance the battery modules within each of the battery strings.

A handheld jump starter device includes a rechargeable lithium battery pack comprising at least three lithium battery cells, a housing for enclosing the rechargeable lithium battery pack, and a jumper cable assembly removably attachable to the housing, the jumper cable assembly comprising a plug and a pair of cables, wherein the plug is configured to attach to the housing in a specific orientation.

An example system includes a first battery; a second battery; a switch coupled to the first battery and the second battery, the switch configured to, based on a control signal, connect or disconnect at least one of the first battery from a load or the second battery from a load; and a current sensor to generate the control signal, the current sensor including a first sensor input terminal and a second sensor input terminal; and an amplifier configured to operate as an amplifier to determine an amount of current between the first sensor input terminal and the second sensor input terminal; and operate as a comparator to determine a direction of the current between the first sensor input terminal and the second sensor input terminal, the control signal corresponding to at least one of the amount of current or the direction of the current.

A battery protection circuit that prevents an over-discharge condition of a battery and a reverse polarity battery charger protection circuit. The battery protection circuit includes a battery input configured to receive a battery voltage, a reference voltage input configured to receive a low battery reference voltage, a comparator for comparing a first signal indicative of the battery voltage with a second signal indicative of the reference voltage and generating an output indicative of a low battery voltage, a feedback resistor coupling the output of the comparator to the reference voltage input to create hysteresis and a battery disconnect circuit to disconnect the battery voltage applied to a load. The reverse polarity battery charger protection circuit has relay and a diode to detect reverse polarity connection of the charge to the battery.

According to a first aspect of the present disclosed subject matter, a configurable harvester energized by radio-frequency (RF) inputs and stores direct current (DC) in an accumulator, the harvester comprises: a plurality of gangs each comprising at least one rectifier powered by RF input; and at least one selector configured to interconnect the gangs either in series or in parallel; wherein an output of the interconnected gangs charges the accumulator with DC.

A protection circuit is disclosed for use in automotive or industrial high power integrated circuits equipped with reverse battery protection and reverse current protection. The protection circuit prevents formation of parasitic devices that could cause the high power integrated circuit to malfunction or fail to turn on. The protection circuit features asynchronous operation of a pair of MOSFETs coupled between a power supply and a load. The protection circuit can be engaged at start-up or in response to transient conditions associated with a fault.

An interposer accessory fits between a two-way radio and its removable battery and maintains pass-through power connections between them, with any auxiliary communication contact passed through without termination. Power-conversion circuitry provides at least one regulated external output, for example a 5 V USB output accessible from the housing. In some embodiments the interposer further includes a USB input interface configured to accept external power and charge the attached battery through a unidirectional and/or OR-ing arrangement. The accessory can retain the radio's form factor using tabs and a spring latch with a thumb release, and may include indicators that convey charge state at the housing. The interfaces can be dimensioned for different radio families while preserving the pass-through connections and external output. USB Power Delivery capability is optional.