Home Lift
Why a Home Lift Should Run on a Battery in Indonesia
The Tenkai V300 takes its power from a battery, and the mains only charges that battery. Three things follow: the lift keeps running through a power cut, the house sees a slow charging draw instead of a surge each time the car starts, and that charging can happen off-peak or from solar. On a grid where a household buys a fixed connected load and an interruption is a condition to design for rather than an accident, that changes both what the lift costs to run and whether it can be installed at all.
- Written by
- Calvin A. W
- Technical review
- Tommy C
- Published
- Updated
- Reading time
- 8 min
What battery driven means here
V300 is the SJEC V300 under the Tenkai badge. What is new is the drive: the battery system SJEC calls Cube sits on top of the existing traction machine rather than replacing it, so the mechanical specification is unchanged and the battery is an addition rather than a redesign.
The load-bearing word is only. The mains charges the battery; the battery drives the lift. A conventional lift is a motor the grid drives directly, and the grid absorbs every start. Here the grid never meets the motor. It meets a charger.
Almost everything else worth saying about this lift follows from that one change, so it is worth being precise about it before going further.
A lift is a strange electrical load
A lift is a spiky load. A car starting draws far more than a car running, and a lift spends its working life starting — a few seconds of demand, a pause, a few seconds more. The average is modest and the peak is not, and a supply has to be sized for the peak rather than for the average.
That is the whole of the V300's electrical argument, and it is worth stating plainly. A charger is the opposite kind of load. It draws a moderate current for a long time and it does not much mind when. The machine is about 1.1 kW, but the house never starts it, because the grid is not what starts it. What the house has to carry is a charge.
The controller reflects how little is being asked of it: an A3-size unit, 325 × 425 × 50 mm — a sheet of paper, 50 mm thick — with no contactor and no cooling fan in its specification. There is no machine room for it to sit in, and nothing in it that would need one.
Where the environmental case actually is
Four things, in descending order of how confident anyone should be about them.
No oil. Every model in the Tenkai range is traction driven. A hydraulic home lift holds a tank of oil that has to be changed and then disposed of, can weep past seals as they age, and shifts its speed and levelling as the oil warms through the day. Traction has none of that. The most environmentally useful thing about this lift is a consumable it does not have.
A smaller connection, not just a smaller bill. The machine is a permanent-magnet synchronous gearless unit, and the lift runs on single-phase 220 V or on three phase. A house that does not have to be upgraded to three phase in order to have a lift is a house where the cabling, the switchgear and the works around that upgrade also never get built. The quietest environmental saving is usually the infrastructure nobody had to install.
Load moved rather than load added. Because the mains only charges, the timing of the draw comes apart from the timing of the trips. Charging overnight and running through the day is not a trick played on the meter; it is the default behaviour of the architecture.
Somewhere for a panel to put its output. The V300 is listed as solar-panel compatible, with panels supplied separately. Storage is the harder half of solar: a panel produces at midday, and a household mostly wants power in the evening. A lift that already keeps a charged battery is a load that can absorb generation when it happens rather than when it is wanted. It also means there is no array size to get right — a battery takes whatever a panel gives it, so a small array charges more slowly and a larger one more quickly, and neither is wrong.
Why this matters on the Indonesian grid
The power cut is a design condition. Not an edge case to be handled by a rescue device that brings the car to the nearest floor and opens the doors, but an ordinary operating state the lift is expected to work through. The V300 is rated for about 250 floors of travel at full load unplugged. The number matters less than what it removes: for a household that installed a lift because somebody in it cannot manage stairs, a lift that stops during an outage is not an inconvenience. It is the temporary loss of the reason the lift was bought.
Connected load is bought, not assumed. An Indonesian household takes a connected load from PLN in fixed steps rather than an open supply, and a load that spikes is judged on its spike. Replacing a motor the grid starts with a charger the grid feeds changes the shape of what the house has to be rated for.
Off-peak is a grid question before it is a bill question. SJEC's own material presents the running-cost case as up to 40 per cent, on a time-of-use tariff, from charging off-peak and running on the battery at peak. Whether that holds for a particular house depends on the tariff that house is actually on, which is worth checking before it is counted on.
The infrastructure argument is the one that generalises. Whether shifting a load off the evening peak lowers emissions depends on what is generating at each hour, and that varies by grid and by season — it is not automatic, and it would be dishonest to claim it is. What moving load reliably does is lower the peak a network has to be built and maintained to meet. Multiplied across enough connections, demand that can be scheduled is capacity that never has to be poured, strung or shipped. A lift that can be told when to draw is a small instance of the thing an electrifying country needs a great deal of.
What it does not do
It does not make the lift carbon-free. The electricity still comes from wherever that grid's electricity comes from, and a battery moves consumption in time without reducing it.
It does not remove a consumable, it changes which one. Hydraulic oil goes; a battery arrives. Prawita Karya puts its service life at five to six years and a replacement at around Rp 6 to 8 million — a cost to plan for rather than one to be surprised by. Over the life of an installation that trade looks favourable, but it is a trade and should be described as one.
It does not come with solar. The panels are supplied separately, and while their number is not a constraint, there has to be a roof or a canopy above the lift capable of carrying them.
And it does not reduce maintenance. A battery-driven lift has the same doors, ropes, guides and safety gear as any other, and they wear at the same rate.
The case for the V300 is not that it is a green product in the abstract. It is narrower and more defensible than that: it is a lift that asks less of a house's supply, and keeps working when that supply stops.
Worth establishing before specifying one
- The house's connected load, and what else starts on it
- Whether three phase exists, and whether it is worth having
- Which PLN tariff the household is on, and whether a time-of-use option applies
- Where the batteries sit, and what that space has to provide
- Whether solar is planned, and whether there is anything above the lift to mount it on
- Pit depth against the 300 mm minimum, and shaft width against 850–1,400 mm
Sources
Where this comes from
- SJEC V300 product documentation — Cube battery drive, controller specification and rated figures.
- Prawita Karya product range — V300 figures as published on this site.
- PLN tariff structure — Connected-load steps and time-of-use options referred to in general terms; no figures reproduced here.
- Prawita Karya engineering — Machine rating, battery service life and replacement cost, and the minimum supply the company will specify.
FAQ
Common questions
Does the lift still work during a power cut?
Yes, and as normal service rather than as a rescue. The mains only ever charges the battery, so an outage removes the charger and not the drive. The V300 is rated for about 250 floors of travel at full load unplugged.
Does it need three-phase power?
No. The V300 runs on single-phase 220 V or on three phase. For a house without three phase, that removes a supply upgrade from the project.
How much electricity supply does the V300 need?
In theory about 2,500 W. In practice Prawita Karya specifies 3,000 W, because a supply that is only just large enough is a supply that trips when something else in the house starts at the same moment. The machine itself is about 1.1 kW, and the lift runs on single-phase 220 V or on three phase. Send us your connected load and our engineers will work it through against whatever else is on it.
How long does the battery last, and what does a replacement cost?
Prawita Karya puts the service life at five to six years and a replacement at around Rp 6 to 8 million. The V300 carries a battery management system as standard, so the pack is monitored rather than guessed at, and the interval moves with how hard the lift is worked.
Can it run on solar?
Yes, and the array does not have to be sized against the lift. The V300 is listed as solar-panel compatible, with panels supplied separately; because they charge a battery rather than drive the machine, whatever they generate is useful and a smaller array simply contributes less. The question is not how many panels but whether there is somewhere above the lift to put them.
Is it actually cheaper to run than a conventional home lift?
SJEC's material presents up to 40 per cent, on a time-of-use tariff, from charging off-peak and running on the battery at peak. That figure assumes a tariff with a peak and an off-peak rate; on a flat tariff the saving is whatever the drive itself is more efficient by, which is a smaller and different claim.