When is a Lithium battery not . . .?

Not sure if this is the correct category for this question . . .
There are a couple (at least) of 24V 50Ah 1kVA 1kW inverter trolleys that would appear to originate from a single manufacturer. They boast true sine wave output, LiFePO4 2000 cycle battery and a MPPT PV converter as well. All at a good price and in stock!
Problem is they weigh 29kg which would be the weight of a PbSO4 battery job. A local LiFePO4 battery of around 1kWh would weigh in at around 10 - 11kg, and a 1kW inverter a few kg. A popular portable UPS with a similar spec weighs < 10kg. So what gives with these UPSs?

You talking about these?


Yes indeed. I was assured the excess weight was due to the steel chassis. I thought that maybe someone translated lbs. into kg … that would work, but i was unable to persuade them to to go weigh one … LOL. Additionally I could not extricate a guarantee on the battery longer than one year.

A single 12V 100Ah battery is approx 28kg.
The Mecer has a 24V 50Ah battery. For maximum life of a lead acid battery they should be discharged only to 50% SOC. So the Mecer unit with LiFePo4 battery needs to be compared with a unit fitted with 2x12V 100Ah lead acid battery. With a claimed 2000 cycle count of 2000, the lithium unit is a no-brainer. The lithium battery will have lost capacity after the 2000 cycles but certainly won’t “die” as suddenly as a lead acid battery. PS My in-laws have one of those Mecer units.