How do you choose between 48V 280Ah, 300Ah and 420Ah lithium forklift batteries?

Direct answer: Compare energy per shift, charge current, size, weight and protection rating, not the Ah figure alone. By the published tables the three are 14.33 kWh, 15.56 kWh and 21.5 kWh, with maximum charge current of 150A, 150A and 200A, so a full charge takes a similar minimum time but the 420Ah pack carries about 50% more energy.

All three are 51.2V LiFePO4 packs with an operating window of 40–58.4V and a rated life stated as “5 years or 3500 cycles (DOD 70% 0.25C)”. They differ in the figures below. Page labels can mislead: the 300Ah page lists 304Ah, which matches 15.56 kWh, so compare kWh rather than the Ah in the title.

The 280Ah pack: 14.33 kWh, 680 × 408 × 450 mm, about 120 kg, 150A charge, 160A continuous, 800A peak for 5 seconds, 8 kW output, IP54, SoC and SoH, and a Forklift Cloud Monitoring System. The 300Ah (304Ah) pack: 15.56 kWh, 940 × 260 × 520 mm, about 164 kg, 150A charge, 300A continuous, 600A peak for 3 seconds, IP40, no LCD, PC-software monitoring. The 420Ah pack: 21.5 kWh, 950 × 421 × 450 mm, about 190 kg, 200A charge, 300A continuous, 1,000A peak for 5 seconds, 12 kW output, IP54.

Charging speed is closer than the capacities suggest. Ah ÷ charge amps gives a floor of about 1.9 hours for 280Ah at 150A, about 2.0 hours for 304Ah at 150A and about 2.1 hours for 420Ah at 200A, before any taper. The 420Ah page’s FAQ text mentions 80% in 1–1.5 hours, but 80% of 420Ah at 200A is at least about 1.7 hours by arithmetic. Ask Redway which charger and conditions that statement assumes.

Pick by duty. If a truck uses less than about 14 kWh in a shift, the larger packs add weight and cost without adding benefit. If it runs near the limit, a bigger pack lets you avoid mid-shift charging, as discussed in our post on sizing from lead-acid Ah. Check compartment fit first, because the three have different footprints, and read the environment: IP40 is not the same as IP54 where there is dust or washdown.

Not published: truck-model approvals, the exact charger protocol and how weight compares with your lead-acid unit. Ask Redway for those in writing, and for the exact model code on the quote, so the 300Ah and 304Ah labels do not cause a mismatch.