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

sujsuj

molerat said:

You have most likely killed the battery.

I forgotten to mention twice I managed to start mower in last 1 week after draining battery for 3 weeks..
First attempt it started and I didn't move it out of garage as it was in the night..
Second time I managed to reverse mower out but got stuck while reversing it..

ThisIsWeird

Lawd, I was determined to not answer on this thread... :-(

SS, what voltage is the mower battery? If you do not answer that Q, I will never speak to you again.

But, you may be right - that last video does seem to indicate a problem that ain't just a damaged battery. Confirm - it shows you turning the key to the first 'ignition' setting, whereupon the front light comes one - and brightly? You then turn the key to the 'crank' position, and there's a wee 'clunk' and the headlight goes off. And it stays off even after you release the key from the 'crank' position back to the 'ignition' position?

When you turn the key fully off, and redo the process, the headlight comes on again, but goes off with 'crank'?

That does suggest a poor connection, tho' a very weird one - it's just a bit too 'on' and 'off' to be a bad connection. You'd expect some 'glimmer', or the headlight coming back on when the key is released. Unless there's some protective electronics there - the kind you get in a car that prevents you turning to 'crank' again after the first try, so you have to back it off fully before a retry.

Who the hell knows...

SS, contact the mower manufacturer and ask.

Then, if it's a 12V battery, connect your car battery to the mower battery using jump leads, and try again. If it now works, then I guess your mower battery is a dud. 

sujsuj

After charging battery for days, it is fully charged now. I am certain now this is not a battery problem. I added more petrol to ensure no fuel issue...

Please help me with step by step way to diagnose this issue.. 

Story so far..
- I left ignition on (head light glowing) state my Ride on mower for 3 weeks
- Found battery drained when came back...
- Charged couple of days, then I managed to start mower but it was night so didn't move out
- Charged again then managed to reverse till edge then stopped again..
- Now Fully charged again, but when I turn the switch headlight comes on first and off in next turn its - no cranking sound!!

Please help, I think this is smaller issue compared to the big issue I faced 2 months ago. I am confident with step by by step checks this can be sorted . Please help. Thanks very much.

 

ThisIsWeird

You ask for advice, and we ask you Qs in order to assist. Do you know what voltage the mower battery is yet? You don't?! Well, please find out.

If it's 12V, then connect your car battery to the mower battery using proper jump leads. That will/should tell you instantly if it's a knackered battery issue or something more. If it fires up, it suggests your mower battery is knacked. If, instead, it just goes 'click' and the headlamp goes off as before, then there's clearly a bigger issue such as a poor connection somewhere. It's really that simple.

I think all you can do is the obvious checking of electrical connections. 

Start at the battery terminals. Undo them. Check them. Any signs of overheating/scorching? Clean them. Refit them, adding a smear of vaseline to the contact surfaces first. Make sure they're nice and secure.

Follow the cables, one at a time, to the next device. Ditto.

That's it. That's really all you can do.

Section62

ThisIsWeird said:

You ask for advice, and we ask you Qs in order to assist. Do you know what voltage the mower battery is yet? You don't?! Well, please find out.

The "12V" written on the side of the battery in the picture in the OP's first post answered that already.

But.... the idea of using jump leads from a car to get the mower started is one which fills me with dread.  There's a risk of a knackered mower, or worse, a knackered car.

Although these vehicle electrical systems are nominally 12V, the actual voltage (especially when the engine is running) can be significantly higher.  You'd expect most modern cars to be built with robust protection (including against overvoltage) on their electrical systems, but I have doubts the same can be said of a budget Mountfield lawnmower.

If the car's charging circuit is kicking out (say) 15V then there's a risk that feeding that into the mower might cause something to 'pop'... and sujsuj's mower's ordeal finally coming to an end.

The battery is almost certainly end-of-life.  I don't know whether the charger sujsuj is using is reporting a full charge based on voltage or the charging current, but either is not a good measure of whether the battery still has the capability to deliver a cranking current - a battery charged to 13V won't necessarily be able to crank.

A replacement battery is a relatively cheap item.  Much cheaper than the labour cost of a local garage to find out why the car is now no longer starting either. Also likely cheaper than the kit needed to properly test a battery's crank performance.

ThisIsWeird

Good point, S62.

I'm not convinced it's an eol mower battery, tho', by the way the headlamp comes on brightly, goes completely off the instant the key is turned to 'crank', and then remains off when released. That suggests a high-resistance connection to me, and the first place to check for one would be at the mower's battery connections, which SS should do as a matter of course.

Good point about over-voltage, and I guess not worth the risk. I was looking for the quickest 'eliminating' test. Before you try this, SS - and I hope you still do - disconnect one terminal from your car's battery, and connect the jump leads directly to the battery. Be aware radios and stuff may need a security code to reinstate afterwards.

Ectophile

It may be that the battery is in such a poor state that it can power the lights, but it can't turn over the engine.  If the mower jump starts off a car battery, then that's most likely the problem, and you need a new battery.

Do check all the terminals at the battery to make sure they are tight.

A car charging system won't put put 15V unless the alternator is faulty.  They are limited to 14.4V maximum.  That would be pretty much the same voltage as the alternator on the mower.  The voltages for charging 12V lead acid batteries are all the same - around 13.8 to 14.4V.  A healthy charged battery should be at about 12.6V.

ThisIsWeird

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.
I think S62 was more concerned that the basic charging system of the mower could affect the car's sensitive electronics, but - I agree with you - chances should be low.
But very costly if I'm wrong

sujsuj

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.

I think S62 was more concerned that the basic charging system of the mower could affect the car's sensitive electronics, but - I agree with you - chances should be low.

But very costly if I'm wrong

Thanks. I can confirm when I tried to restart after 3 weeks it was weaker non-white light.
Now it is absolute white and glowing very brightly like a tube light!
What I noticed is when turns further light is completely off - I will check this again.
As I said twice i managed to start this mower, so still life is there I think.

Section62

Ectophile said:

A car charging system won't put put 15V unless the alternator is faulty.  They are limited to 14.4V maximum.  That would be pretty much the same voltage as the alternator on the mower.  The voltages for charging 12V lead acid batteries are all the same - around 13.8 to 14.4V.  A healthy charged battery should be at about 12.6V.

That is no longer correct.  For example, Ford have fitted a 'smart charging' system since the late 90's which operates at a nominal 14.8V but adjusts the charging voltage according to factors including the assumed battery temperature and battery state of charge.  For this reason Ford gave dire warnings about only using "Silver-Calcuim" batteries on vehicles fitted with this system, and not jump starting.  The highest charging voltage the system can operate at is somewhere around 18V (in the case of a cold engine with a heavily discharged battery). Other manufacturers may have similar systems.

Domestic-grade lawnmowers typically don't have an alternator and instead use a charging system based on a flywheel magneto-type arrangement with the output passing through a fairly crude rectifier/charge control.  As such the output can be quite dirty and is not something I would willingly feed into a car's expensive and sensitive electrical system.

Without knowing what charging system sujsuj's car uses - and bearing in mind the difficulty in working out what voltage the mower battery is - I would still say that attempting to jump start the mower from the car would be unwise and potentially lead to expensive repair bills for the car in addition.

Also, whilst disconnecting the car's connection to the car battery would afford some protection to the car, the potential for problems when doing that are not limited to having to re-enter the radio code.  The engine and vehicle management systems (including the security/door locking/immobiliser) can also be affected when disconnecting the battery.  For that reason I wouldn't contemplate doing that without using a 'memory saver' device, except in emergency.

In summary, given sujsuj's luck with this lawnmower, risking damage to the car simply to prove the battery is dead is not a good idea.  The jump start may get the mower going, but all the evidence so far points to the battery being damaged by being overdischarged.  The battery won't repair itself.  The best the jump start technique might achieve is getting an additional few weeks or months of use from the mower before having to replace the battery.  Given the potential risks of damage to the car and/or mower it would be sensible to jump straight to the battery replacement now.  The cost of a new battery would be 'moneysaving' compared to the potential costs sujsuj would have if the experiment goes wrong.