Skip to content

Tesla Powerpack Prices Rise By 16% Since 2017

January 27, 2019

By Paul Homewood


The power of the internet!

We often hear that the cost of battery storage keeps coming down in leaps and bounds, but the reality is different, at least as far as Tesla is concerned.


In June 2017, I ran a post on the economics of Tesla Powerwall batteries for domestic use.

This is the what Tesla’s website showed at the time:




Now, lo and behold, we find that the cost has risen by £950, an increase of 16% in a year and a half:




Specification wise, there seems to be no difference, and both are rated at 14 KWh.


Poor old Elon must be desperate to make some money!

  1. January 27, 2019 8:27 pm

    There are still plenty of gullible people about who will be conned by Tesla. How many thousands of home owners have been conned out of thousands of £s by the solarPV and Green Deal scams? There are also many farmers who have been conned into buying loss-making wind turbines. And you can always find councils who are totally incompetent (and ignorant) and are happy to waste council taxpayers’ money on these scams.

  2. January 27, 2019 8:32 pm

    It’d be interesting to ask the idiot Krytenabout that … I’d like to see his response

  3. RAH permalink
    January 27, 2019 8:48 pm

    Tesla is, and has been on shaky financial ground for some time.

  4. Bruce of Newcastle permalink
    January 27, 2019 9:30 pm

    Cobalt went through a big price spike in late 2017. I suspect that also forced Tesla to put up their price.

    By choosing the LiCoO2 system Tesla shows they have little understanding of supply and demand economics. Cobalt is much too rare to support a large battery industry, and new mines take a long time to get into production.

    The Chinese chose the LiFePO4 system. None of those elements are rare, not even the lithium.

  5. Jeff permalink
    January 27, 2019 11:06 pm

    Demand is outpacing supply.
    The backorder list is long.
    Tesla have increased the price probably because they can in this situation.
    Watch out though the competition from China is increasing quickly.
    Their domestic batteries are much cheaper now, whether the quality and features are there IDK.

  6. Mike H permalink
    January 27, 2019 11:20 pm

    Could this simply be the impact of a weaker exchange rate?

  7. Athelstan permalink
    January 28, 2019 12:41 am

    Poor old elon?

    Hmm, buying elon’s guff and halfwit green delusions and extravagantly over priced vainglorious contraptions makes the buyer poor, more like.

  8. January 28, 2019 3:50 am

    Reblogged this on Climate Collections.

  9. Richard Thompson permalink
    January 28, 2019 8:16 am

    Probably hedging bets against a big fall in the pound on a no deal Brexit in march.

  10. January 28, 2019 8:28 am

    Reblogged this on ajmarciniak.

  11. January 28, 2019 10:36 am

    The Tesla Powerwall is not so special and you could probably do the same job CHEAPER with a bank of car batteries and an inverter.
    (though many small things could be powered directly off a 12V rail eg USB charging)
    Does anyone disagree ?

    • Dave Ward permalink
      January 28, 2019 10:57 am

      I could most certainly “do the same job”, but I have decades of practical experience in matters electrical. The average homeowner these days can’t even fit a 3 pin plug! Plenty of “Off Gridders” have something similar, but you wouldn’t use “car batteries”, as they are not designed for frequent charge/discharge use. Tesla is selling to the easily impressed, who (it seems) have money to burn…

      • A C Osborn permalink
        January 28, 2019 11:47 am

        “but you wouldn’t use “car batteries”, as they are not designed for frequent charge/discharge use. ”

        Do what?
        They are discharged and charged many times per day, they may not be completely discharged, but that would be a matter of capacity to achieve the same in a house.
        Stop Start vehicle batteries are discharged and charged every time the vehicle stops/starts, in London, that is about very 2 minutes.

        So you actually mean not designed to be completely discharged and flattened, which would damage them, I assume.

      • RAH permalink
        January 28, 2019 1:31 pm

        “Deep well” marine batteries?
        BTW the climate control system in the 2015 Cascadia freightliner I drive runs off batteries. There is the standard bank under the drivers seat and then the environmental bank between the frame rails below the utility deck (that little deck between the back of the sleeper and the nose of the trailer.

        When I park I set the controls on “idle management”. Then I can run the A/C or the Webasto heater off the batteries. When the voltage output drops below a certain level the truck automatically starts, charges the batteries, then shuts down. In really cold conditions the truck will start when the oil temperature drops too low.

        The system works well. The parked A/C will keep me comfortable up until the outside temperature reaches the mid 90s F. Of course parking in the shade makes a big difference. The Webasto heater is a mini furnace using diesel fuel and has kept me toasty even when temps are below -30 F.

  12. Dave Ward permalink
    January 28, 2019 6:29 pm

    “So you actually mean not designed to be completely discharged and flattened, which would damage them, I assume”

    Yes, I should have made that point more clearly! You won’t automatically damage them, so long as they are not left in this state, particularly in freezing conditions. With lead-acid batteries it is the “Depth Of Discharge” which is important, and any reputable manufacturer will provide a chart showing the number of charge-discharge cycles it can be expected to give, at varying rates of DOD. With a traditional car battery this might typically range from 500 cycles at 30% DOD to as little as 100 at 80% DOD. Stop-Start batteries (usually AGM type) might provide several thousand cycles down to 30% DOD, but a modern car with such a system would normally override the stop-start, and keep the engine running at that sort of discharge level. Starting a modern engine takes only a couple of seconds of high current, and the percentage of the battery charge involved is negligible. It’s powering all the other vehicle systems with the engine stopped which is very different now, compared with the past.

    Going below 50% DOD on a regular basis is not a good idea with a conventional engine starting battery – they have a relatively large number of thin plates, to give a big surface area, and thus high current capabilities. Proper “Deep Cycle” (or sometimes called “Traction” batteries) have thicker plates, which cope much better with regular discharge, but aren’t so good for short term heavy currents. Anyone considering an “Off Grid” setup should be looking for these, unless it’s for occasional use, in which case car batteries are usually cheaper, and would do if you are careful how they are treated.

    Lithium batteries WILL be permanently damaged if fully discharged, and monitoring circuitry is normally included, along with a cut-out to stop this happening. They are now finding their way into marine “Live aboard” applications – despite the considerable extra cost, the ability to provide a greater proportion of their capacity means a smaller pack can do the same job. As an example: most canal boats have 4 x 100 amp/hr lead acid batteries, but you can’t (or shouldn’t) regularly use more than half this. 2 x 100 amp/hr Lithium batteries would only provide 180 amp/hrs useable, but their lower resistance more than compensates for the missing 20. Being able to take higher charge currents mean less engine running time to recover, particularly important when others are living nearby. And a much longer life helps to get back the initial cost.

    • A C Osborn permalink
      January 28, 2019 9:18 pm

      Back in the 1990s when Ford actually made cars in the UK they had a major problem of the Engine Not running type draw on their batteries that cost them a lot of money.
      it was typical in those days for manufaturers to overbuild and store the cars to await the high buying months.
      The draw for the clock, Radio Clock, alarm and CPU caused the batteries to completely drain, although the batteries were then recharged, one or more buckled plates meant that they could not hold the charge.
      So under warranty they had to change them and then replace the then current factory fitted battery with a larger one to allow them to stand for long periods.
      Standing in fields also did for the Disc Brakes as well due to rusting where the Pad was not, leaving a “lump” on the disc leading to Brake Judder.

  13. JRG permalink
    January 29, 2019 9:18 am

    Does currency change have anything to do with it ?

    • January 29, 2019 10:57 am

      I don’t think so, as the pound fell in 2016 after the referendum.

      Since then it has been stable

  14. Mike H permalink
    January 29, 2019 2:16 pm

    For the price of that Tesla battery you could pick up a second-hand Nissan Leaf or similar and park it offroad alongside your house. That would give you a battery capacity of 25-30 kWh in a self-contained package that just needs connecting.
    Would it take much to adapt the circuitry so that it could discharge as well as charge? If not you have an instant domestic battery equivalent to 4 Powerwalls for about the same price!
    And, if you move house, you can take it with you!

    • Dave Ward permalink
      January 29, 2019 4:25 pm

      “Would it take much to adapt the circuitry so that it could discharge as well as charge?”

      Yes, is the simple answer. How much you want to spend, and how technical you are varies the possible solutions. This YouTube video, from a Brit living in the US, shows the “cheap and cheerful method”

      Mitsubishi make the MiEV Power Box, but it seems to be only for the Japanese market:

      “In Japan, it’s sold retail and can be used with the Mitsubishi Motors i-MiEV, Nissan Leaf, Kia Soul EV”

      The idea is, not surprisingly, attracting attention from the DIY brigade – This thread:!
      discusses the YT method, but notes that you should be careful not to draw too much current, or risk blowing a fuse. On p2 is a link:

      which gives some details on how to energise the main high voltage DC socket for the brave (or foolhardy!) who wish to utilise a solar inverter, thereby bypassing the cars own DC-DC converter.

      All of these options are only a rough & ready way to get round short term power cuts. If you want to make it more or less seamless, then you will need your house wiring modified with a proper changeover switch, so there is no risk of the mains and your backup having an argument…

  15. Mike H permalink
    January 29, 2019 10:04 pm

    Thanks Dave.
    I was guessing it would be feasible because of all the pie-in-the-sky ideas about using EVs to back up the grid – in huge numbers, obviously.

    • Dave Ward permalink
      January 30, 2019 11:43 am

      “About using EVs to back up the grid”

      This would come under the heading of “Advanced”, rather than the home-brew ideas I linked to! It will need inverter/chargers (rather than simple chargers) in the home, to allow bi-directional current flow to/from the EV battery, and grid. This would have to be under centralised grid control, which, in turn, needs the internet (or possibly mobile phone networks). Yet both of these are at the mercy of mains power, with varying degrees of their own back-up, so a major grid outage will be challenging. It would also not provide the homeowner with back-up power, unless an isolating changeover switch or contactor is installed. The same thing applies to solar PV installations, which automatically shut down if the mains fails. It’s known as “Anti-Islanding Protection” and I’ll bet few owners know about it.

      I did some searching for second hand and accident damaged EV’s. The cheapest Leaf was just under £6k, and various battery packs are available from breakers yards. There are plenty of YT videos and other information about “Re Purposing” EV batteries for Off Grid and back-up uses.


  16. Mike H permalink
    January 31, 2019 4:53 pm

    Dave; I imagine a written-off Tesla might be interesting as well, in terms of bang-for-buck.
    In a similar vein, I wonder how long it will be before we see trucks being fitted with a chunky generator on the back and the necessary electronics, cables, etc so they can offer a mobile recharging service…..

  17. January 31, 2019 9:45 pm

    Dave Ward : despite your initial comment I think you saying a car battery rig would work the same and you’d put circuitry in to manage discharge limits which as you admit can be quite flexible ” several thousand cycles down to 30% DOD”
    So it’s a question of having enough batteries so that you stay within the limits
    ..still it would be massively cheaper than the Tesla

    Indeed we know that camper van and yacht battery banks are doing the same job as a Tesla and have the protection circuitry built in .

Comments are closed.

%d bloggers like this: