Retaining Dyson V8

[Scott]

I have never been greatly impressed with this appliance. The battery life is very restricted (especially on the high power setting). It is not as powerful as I expected for removing dirt. As the battery has now deteriorated, I was thinking about buying a new unit. However, the Miele that I like the look of costs about £650, which does not meet the value for money test at present.

I see that it is very easy to replace the battery. Is this machine likely to last the lifetime of a new battery? Also, I see that the battery is supposed to allowed to cool before charging. I was totally unaware of this and regularly put it straight on the charger. Is this likely to have affected the battery life significantly?

[Martin Brown]

The Dyson battery is vastly overpriced - paying for the brandname. Clones seem to work better than OK but you could be unlucky.

Unclear. They do get truly mad hot ~60C in use so it is possible that they can already be too hot and overheat when immediately recharged.

Certainly our replacement clone battery has already lasted about twice as long as the original Dyson one that came with the kit. This might well be partly due to allowing it to cool as instructed.

I did notice that the clone replacement batteries have that warning.

[Tim Streater]

Any suggestions about where to get clone Dyson batteries? We have a DC35, almost 10 years old now, and the battery is only lasting a few minutes. It cuts out and then can continue for about a minute at a time. I did get a clone off Amazon but that after being charged hardly ran at all.

The DC35 itself works fine.

[Michael Chare]

I have bought several batteries for a V6 and an earlier model on ebay. The batteries themselves have electronics just above them which may well ensure that they don't get to hot. When I dissembled an old battery unit to inspect the contents I damaged the plastic case.

[Martin Brown]

Mine was also from Amazon branded Yaber (link shows no longer available)

[John Rumm]

To be fair, all cordless vacuums have limitations on run time and power

- it is quite a high current drain application.

No reason why not - I presume it is a brushless motor, so not much to wear out.

Yes. Charging hot batteries is not good for them. That is why many modern power tools have chargers with temperature sensors and forced air cooling. If you put a hot battery on it, it will not start charging it until it has cooled it a bit first.

[Scott]

That's me persuaded. I'll go for the life extension option and take more care with the battery.

[Theo]

When I did the calculation it was about 400W on the max setting, so the reduced power is unsurprising compared with a 1kW+ mains vacuum.

Dysons tend to die because their plasticy bits fail rather than the motors going, unless abused. But there's a thriving aftermarket of used plastic bits so they are repairable if needed.

The aftermarket batteries have a simpler BMS than the Dyson ones, although I'm not sure how much of a difference that makes.

When I've finished with mine the casing is only ~30-40C which I think is ok for a battery, although the cells may be warmer inside (there is no ventilation, just conduction through the plastic). I do leave it and plug it in a few hours later - not noticed any degradation problems. (it was secondhand and may itself be an aftermarket battery)

Theo

[Scott]

I assumed being a Dyson design it would be more efficient.

Ironically, the bit that has sustained damage here is aluminium. Good point - Dyson is surprisingly good with spares and I expect the Dyson shop near me probably does a good line in cannibalisation.

I'm going to go for OEM. Compared with new Miele at £650 it's a bargain.

New charging protocol needed in this household.

[Martin Brown]

Dyson is a very effective self publicist which enables him to charge more for less.

There is quite often a guy on the local weekly market with spares and/or a good line in reconditioned working ones.

Obviously your choice but I found the third party unit perfectly acceptable and it came with the warning about allowing the battery to cool before recharging. Ours gets too hot to touch if used nearly continuously for the full battery capacity (and always did).

Recharging should be OK once it is down to about 30C. Only when the battery is 40C or above (or sub zero) do you risk damaging the cells.