36V forklift lithium: 250Ah or 700Ah (690Ah) for your truck?

Direct answer: Start from each truck’s battery specification, not from the battery list. The 36V 250Ah model is a 9.2 kWh pack listed at 870 × 400 × 430 mm; the 36V 700Ah model is a 26.5 kWh pack at 967 × 515 × 779 mm. They fit different compartments and weight ranges. Choose the one whose size and weight match the truck maker’s battery spec, then check that its energy covers your shift and that charging fits your breaks.

Page figures. 36V 250Ah: 38.4V, 240Ah, 9.216 kWh, 870 × 400 × 430 mm, about 250 kg, 120A maximum continuous charge, 240A continuous discharge, 720A peak for 3s, IP40. 36V 700Ah: 38.4V, 690Ah, 26.5 kWh, 967 × 515 × 779 mm, about 330 kg, 150A charge, 320A continuous, 480A peak for 5s, IP65. Both list RS485 / CAN bus / 4G, Rema connector and “5 years or 3500 cycles (DOD 70% 0.25C)”. Note that the names (250Ah, 700Ah) differ from the table capacities (240Ah, 690Ah).

Fit and weight decide first. The two packs have very different heights (430 vs 779 mm). Compare each with the measured compartment and the truck data plate’s battery weight range. OSHA requires the truck maker’s prior written approval for modifications that affect capacity and safe operation, which covers a battery outside the specified weight; see fit and counterweight checks.

Energy against the shift. Measure or estimate energy used per shift. The larger pack stores almost three times as much (our arithmetic: 26.5 ÷ 9.2 ≈ 2.9). If the truck uses well under 9 kWh per shift and can charge in breaks, the smaller pack may be enough. For converting your current lead-acid Ah, see sizing from lead-acid Ah.

Current against the truck. Check the truck controller’s maximum current and duration against 240A/720A (3s) and 320A/480A (5s). Peak durations differ, so compare carefully.

Charging. Our arithmetic: at maximum continuous charge, refilling from empty takes about 2 hours for the 240Ah pack (240 ÷ 120) and about 4.6 hours for the 690Ah pack (690 ÷ 150), longer in practice near full. Size chargers and the electrical supply accordingly. Both list natural cooling; keep airflow around the pack and charger.