Dyson V6 Absolute Not Starting

[VitalComputing]

Hi everybody,

I bought one of these and the batteries are a disaster with them. I have a second dud battery now and I'm just about to throw the thing in the bin.

The battery is rated 21.6V and supplies up to 16A. I connected two 12V lead acid batteries in series to test the motor - the dyson starts and then stops after two seconds. I'm not sure why, maybe it is the overvoltage protection or maybe the batteries can't supply the required current.

I'm just wondering if I put two lead acid car batteries (which would have the required current capacity) in series for 24V, drop down to 21.6V using high current diodes (in case the 24V is too much), would it do the job? Has anybody toyed around with powering with an alternative power source? Obviously I would have to carry around the car batteries but I would just put together a Ghostbusters type carry bag, so this would not be an issue.

[sam_sam_sam]

If you have some 20 volt tool battery packs you could test this device I would caution you that these type of battery pack have a certain amount of current that you pull from the BMS protection board so be aware of this limitation

3 to 5 amps is the normal range higher preforms tools range is about 5 to 8 amps

Impact gun ,die grinder , grinder would fall in the 5 to 8 amp range

Drill driver 1/4 impact gun regulator drill fall in the 3 to 5 amp range

One other caution you should be aware of is that some battery packs do have have BMS protection boards they are part of the charger and the tool has a voltage/current monitor circuit

You can sometimes tell if this is the case it will have each battery cell voltage can be measured on the connector pins if this is the case do NOT use this type of battery pack to test your device in question you will no current protection for the batteries in the pack

The other option is to replace the defective batteries with good ones and try retesting them if you do this remember that you have to reactive the battery pack by putting it on the charger before you can test the device

I would have to agree with you suspicion that it might over voltage detection circuit which would not surprise me in the least

If you have two battery packs you might get lucky and have enough good batteries out two battery packs to make a good one for awhile

Do you know what size batteries they 18650 , 21650 and so on

I hope this helps you with this type of repair

[VitalComputing]

Hi Sam,

Thanks for your reply. I have drawn up a quick electronic diagram of what I'm proposing. To be honest I expected to look up youtube and find someone who had done similar, or at least a good reason why it could not be done. But I will put the circuit up there for somebody to critique. Maybe the dyson battery module also provides regulation or preparation of the voltage before it is fed to the dyson itself.

I'm pretty sure they use the 18650 batteries, and I have a good few spares of these in old laptop batteries. But I think the issue with the Dyson battery module is more that the electronics around the battery fail, not that the cells themselves fail. This is another option for something that I could try though.

[sam_sam_sam]

I would add one more diode for good measure first if it works correctly with this then you could remove the extra one and see if the circuit like this situation

You could do this but I would at least use 3 amp diodes for this test so you do short them out
I would not continuously run it on this setup unless you use 10 amp diodes at a minimum just to be on the safe side

One thing I would recommend that you load test the 18650 cells with a automotive type headlight and record the time that the voltage is above 3.0 but make sure that you start with a fully charged battery 4.2 maximum and group them ( your time testing above 3.0 volts) as close as possible for best results with the BMS protection board unless it has balancing protection as well most of the BMS boards do not have the balancing feature on them

You can charge 18650 batteries with out a BMS protection board but you need to have an adjustable power supply that can control current as well as voltage to do this safely charging current should not be more than one amp current and set voltage to 4.1 volts and should be alright but do not walk away from them when charging these batteries if you do not know the history of them you need to check them out for temperature issues while charging them

If you want to walk away from them while charging do not go over 200 milliamperes current while charging them every so often I would still check the temperature on them when the charging voltage gets close to 3.8 volts and beyond this voltage until fully charged

They should stay at room temperature or a little bit higher than but not so warm that you can not comfortably keep your hands on them if they are higher than room temperature the warmer they are beyond this temperature I would hesitated using them for this device but this just me personally one note if use the ones warmer than room temperature I would have all the batteries cells that are basically the same temperature when charging for best results but what your results will be are anybody guess

One final note if you have a battery testing machine that has a temperature sensor in the controller this makes testing and grouping batteries a lot easier

[CapLeaker]

What is this Dyson? A cordless vacuum? I remember a friend of mine had the same problem, but can’t remember what was the problem. Apparently there is a lot of them that have trouble at roughly a year went by.
If it would be mine I just hook my CC CV each power supply to it and crank her up.

[VitalComputing]

Sorry I thought these were sold worldwide. The word Dyson here is synonmous with hoover. It is an upright hoover, though it barely hooves that much these days.

[petehall347]

is the dyson fully intact when testing ?

[VitalComputing]

Originally Posted by petehall347

is the dyson fully intact when testing ?

Yeah it's fully intact, aside from the battery of course. There are two terminals from the battery that I have identified as positive and negative - I have pulled out the Dyson battery and have connected the terminals from the battery. These things are very temperamental as hell though, so I certainly have not ruled out it stopping after two seconds because of some other, non battery related issue. They are notorious for stopping because of issues with the filter and things like that.

I'm going to order a few of these to drop the voltage anyway and see what happens.

diode.jpg
https://ie.farnell.com/ixys-semicond...00v/dp/1080095