Mountfield R28M ride on Mower (Again!!) - Kept Ignition ON for 3 weeks and now Not starting..!

Section62

ThisIsWeird said:

I'd expect a failing battery to display a somewhat weaker headlamp - not pure white like that one - followed by going very dim with an attempted crank, but returning to a glow of some degree when key released. This one remains deed.

The problem with a failed/failing lead-acid battery is usually in its ability to hold charge and deliver cranking current.  It can be possible to charge them to 13.xV but achieving very little stored energy.  The headlamp bulb will be a few tens of watts (less if LED) and doesn't need much current to make it illuminate brightly (at least initially).

The cold cranking current requirement will typically be in the tens of Amps... potentially taking a fraction of a second to discharge the battery.

Probably easiest to think of a dead lead-acid battery as being like a capacitor. You can 'charge' it to 'x' Volts and then apply a small load (like a torch bulb) which will work well to start with, but not for long.  If the capacitor has been shorted (which is what the starter motor does in effect) then the bulb is not going to illuminate, as no charge remains.

The behaviour you are expecting is more like that of a chemical battery (e.g. zinc-carbon or alkaline) which may have enough chemical energy left to illuminate a lamp after being 'shorted' by a heavier load.  But a failing/failed lead-acid battery usually won't have this kind of 'recovery' without external charging.

ThisIsWeird

Section62 said:

ThisIsWeird said:

I'd expect a failing battery to display a somewhat weaker headlamp - not pure white like that one - followed by going very dim with an attempted crank, but returning to a glow of some degree when key released. This one remains deed.

The problem with a failed/failing lead-acid battery is usually in its ability to hold charge and deliver cranking current.  It can be possible to charge them to 13.xV but achieving very little stored energy.  The headlamp bulb will be a few tens of watts (less if LED) and doesn't need much current to make it illuminate brightly (at least initially).

The cold cranking current requirement will typically be in the tens of Amps... potentially taking a fraction of a second to discharge the battery.

Probably easiest to think of a dead lead-acid battery as being like a capacitor. You can 'charge' it to 'x' Volts and then apply a small load (like a torch bulb) which will work well to start with, but not for long.  If the capacitor has been shorted (which is what the starter motor does in effect) then the bulb is not going to illuminate, as no charge remains.

The behaviour you are expecting is more like that of a chemical battery (e.g. zinc-carbon or alkaline) which may have enough chemical energy left to illuminate a lamp after being 'shorted' by a heavier load.  But a failing/failed lead-acid battery usually won't have this kind of 'recovery' without external charging.

I agree. But the symptoms shown in SS's vid would still be pretty extreme even for lead-acid. I think it's more typical of a high-resistance type fault - which can be 'instant' - but it could certainly be either.

If SS hasn't carried out the basic checks - redoing the battery terminals, traced the battery cables to their next points of contact - then, well, you know - I'm out...

Until the next time I post :-(

sujsuj

Looks like I am lucky again!!

Followed instructions here, I was planning to remove battery to clean & connect again.
But before I managed to find Red battery terminal cover (which I removed for charging) and now all good and Mower working perfectly!! I just finished 1 round mowing and starting next round after a break!

I am hoping it is due to what I did terminal cover shown in the pic, or it could very well random..??
Thanks everyone again..

sujsuj

thank you ..

Section62

sujsuj said:

I am hoping it is due to what I did terminal cover shown in the pic, or it could very well random..??

Moving the terminal shroud could (temporarily) overcome a problem with a poor connection.... but is it sunny and hot where you are today?

Given your previous experience with the mower starting on two occasions I would be willing to guess that on a warmer day (and restarting when the engine is hot) has meant that a lower cranking current was required, and the battery performance was slightly better, with the combined effect of the engine starting.

Not 'random', but also not necessarily what you did with the terminal.

ThisIsWeird

'Random' doesn't even begin to cover this...

ThisIsWeird

How about a piccie with the red cover lifted, SS? You know, something useful

prowla

Call out the AA.

ThisIsWeird

prowla said:

Call out the AA.

I can see SS in 'that' advert, standing beside a scorched piece of grass and only a  blackened mower seat remaining; "It's ok - I'm with youknowwho..."

Section62

ThisIsWeird said:

prowla said:

Call out the AA.

I can see SS in 'that' advert, standing beside a scorched piece of grass and only a  blackened mower seat remaining; "It's ok - I'm with uouknowwho..."

Probably only the steering wheel... the fuel tank is somewhere close by the seat.