Help: Cordless angle grinder keeps shutting down?

When I switch on my cordless angle grinder it keeps shutting down seconds later, especially when I touch my piece of work. It was working ok yesterday but occasionally in the past it shuts down. Now it’s doing it every time I switch it on.

The battery is well charged and healthy

Thanks in advance for any replies.

How many charge cycles has the battery done?

I don't thnk you can 'know' that the battery is healthy when under load, notwithstanding a long charge and good voltage on a voltmeter Can you try another battery to rule out a fault with the grinder? Symptoms are those of a failing battery, as hinted.

Edited By john halfpenny on 09/06/2022 19:03:02

I have a Makita one, and the larger capacity packs are recommended. They do tend to pull quite a bit of power, so normally use a 5 or 6Ah one.

Maybe your grinder has a built in automatic safety protection, which could be faulty.

MichaelR

Please can you tell us the make and model of grinder.

Do you have any other tools that take the same battery? Does the battery work well _under_ _load_in the other tool?

Does it have a momentary switch that you need to keep pressed to operate it? Or is it a latching on-off switch? When it shuts down, if you switch it off and then back on again, does it resume working?

If it is easy to do so, open it up and check for loose connections, intermittantly broken wires or dry solder joints.

Edited By Simon Robinson 4 on 09/06/2022 20:11:37

I have Ryobi 18v system. The dropsaw that I have will not work with their new 9amp battery. The newest drop saw does work with the 9amp battery. Apparently in the battery is a current draw control circuit. The new models have some form of ramping the start and reduces the current draw at start up. I have found that the 4amp/h batteries seem to be able to take a higher current draw. So I have only stuck with those. My circular saw from 2003 is also a high current starter, as it was from the days of Nicad batteries. It also did not start on the 9amp battery. Would just turn over and before full rpm, it shut down like the battery is not charged .

..Are you sure the switch latches - one of the newer grinders I've had have a kind of 'dead-mans-handle' switch that cuts off if you relax your grip even a bit - it needs a strangle hold to keep it on..

...'though after checking, I find it does latch if I wring it's neck - probably best to disregard this post - apologies..

Edited By DiogenesII on 09/06/2022 20:57:06

Edited By DiogenesII on 09/06/2022 21:00:10

When you switch on and push the switch to the on position try holding it there with a little pressure if the machine then continues to run then a faulty switch probabily dirty

Angle grinders use a lot more power than a drill. I have a Ryobi angle grinder which would only work for 3-4 minutes with a fully charged 2ah battery. When I use a 5ah battery I can get more than 10 minutes of heavy use.

Sticky brushes? Try tapping on body to free them up and see it it then starts.

Simon says it starts but shuts down when applying a load.

If it's recently new, Lidl, Aldi and similar shops tend to have quite generous warranties, possibly 3 years. I'd be tempted to take it back if this is the case.

If it does exactly! the same pattern of starting, then cutting out every time, I'd say it's more a controller fault (if it has one). Parts for Parkside tools don't seem to be readily available.

If intermittent or the run/stop action is not exactly the same very time, then as others have said, check the brushes and holders.

If it has a wound field coil, check where the ends of the coils are terminated into spade connectors. These enamelled wires can sometimes burn out but may still appear to be connected. Not always obvious.

If it has a permanent magnet field, check that the magnets are secured to their outer sleeve, they sometimes become loose.

Also check the battery connector has good connections, no loose spades or broken solder joints inside heat-shrink.

Ed.