Choose capacity from your actual energy use. Add the watt-hours or amp-hours consumed by fridges, lights, pumps, electronics, inverters and other 12V loads over a typical day, then allow reserve for longer run times and periods when charging is limited. Also check current, not just capacity: high-draw equipment must stay within the battery BMS continuous and peak discharge ratings. Trolltek's 12V range includes conventional and slimline formats, so physical space and terminal access can influence the choice as much as amp-hours. For a caravan or 4WD system, consider how quickly the battery can be recharged from solar, DC/DC or 240V mains. A larger battery provides more stored energy, but it also requires enough charging capacity to recover it.

Yes, provided the inverter's DC input is 12V and its current demand remains within the battery, cabling and connection limits. Inverters can draw very high current: a large AC load may require well over 100A on the 12V side once conversion losses are considered. Check the inverter's continuous and surge power, convert that to approximate battery current and compare it with the battery BMS discharge rating. Use short, heavy battery cables, appropriately rated lugs, a DC-rated isolation device and a fuse sized to protect the cable. Do not rely on a small accessory connector for a high-power inverter unless its rating is adequate. If the expected load is consistently very large, a higher-voltage battery system can reduce DC current and cable size.

The main difference is packaging. A conventional battery case is suited to standard trays and battery compartments, while a slimline battery is designed to fit narrow spaces commonly found behind 4WD seats, in storage compartments or against caravan cabinetry. Capacity, BMS rating, terminal layout, connection options and environmental protection can differ between models, so the choice should not be based on shape alone. Measure the installation space including clearance for cables and connectors. A slim battery still needs rigid restraint so vibration is not transferred through the terminals. If the battery will be installed in an exposed or wet location, compare the enclosure rating of the exact model because a slimline case may not have the same sealing specification as another Trolltek battery.

Yes, but the preferred arrangement is through a lithium-compatible DC/DC charger rather than a simple direct battery-to-battery cable. A DC/DC charger controls voltage and limits current, helping protect both the LiFePO4 battery and the vehicle charging system. Choose charger output current with regard to the alternator's available capacity, particularly on modern vehicles with smart alternators or on engines that produce limited output at idle. Size the input and output cables for current and run length and protect them with correctly located fuses. Depending on the charger and vehicle, an ignition trigger or programmable VSR can be used so charging occurs only when suitable source voltage is available.

Some Trolltek 12V models support parallel connection for greater capacity and may also permit a limited number of batteries in series to create a higher-voltage bank; the exact model specification should always be checked before wiring them together. Batteries used in one bank should be the same model, capacity and chemistry and ideally similar in age and state of charge. Use equal-length, equal-size interconnect cables so current shares as evenly as practical, and fuse/protect the bank according to the system design. Do not mix a partially charged battery with a fully charged battery and immediately parallel them, as a high equalisation current can flow. For 24V, 36V or 48V applications, a purpose-built Trolltek battery at the required voltage can simplify the installation.