Electric forklift charger problems

[richy_B]

Hello,

I've got a pretty ancient electric forklift (Invicta) and charger (Legg). I've had it a year and in honesty only use it for an hour or so a week to shift a few pallets about. I usually charge it once a month when it becomes sluggish. Today I've plug it in as per usual and nothing. Electrics is not my strong point but I am wondering if anyone has any ideas. I've topped up the batteries with deionised water. They all seem to be at the right level. I've unplugged the charger from the mains, unplug forklift, reset the timer, etc. Tried it all again a few times and nothing. I've tried normal charge and equalising charge. The circuit breaker hasn't gone or anything.

 

When the battery is attached to the forklift its shows 40V so I assume the batteries are all linked ok.

 

I assume the socket is ok but I do not have anything else with a 32A blue plug to test it.

 

I popped the back cover from the charger to look for the 'smoking gun' but there isn't anything loose/melted/suspicious.

 

Any ideas?

[cornish wood burner]

First thing you need to establish is power to the charger.

They normally have a mains and output fuse. Check them. Have you a multimeter, if so try and trace the circuit through the charger. They are more complicated than you would think though. Probably have a monitor circuit which triggers a relay.

Check the transformer output and input coils. Any printed circuit boards in there, have a look at for blackened components. If electrics are not your strong point then you might need outside help.

Just a few ideas for you to start on.

Edited September 24, 2014 by cornish wood burner

[richy_B]

Much appreciated. The main problem is its all very old. Not sure exactly how old but its says 'Made in USSR' ! Leading on from that the info inside on various panels etc is written in what appears to be Russian.

 

Yes, I did think that checking the socket was number one. The MCB breaker didn't go at the fuse box so hopefully that is ok. I haven't got anything else that runs on a 32a blue plug of that size unfortunately which would be an easy test.

 

On the inside of the charger I cannot see anything that looks like a conventional fuse. There is what seems to be a liquid (mercury looking) fuse on the timer.

 

Everything is crudded up inside, 25+ years of dust etc. Nothing looks took suspect though (melted/corroded).

 

It might be easier to get a new charger. Will have to work out what I need though. It has 20 single cell batteries running in series so I guess it is a 40V system.

[cornish wood burner]

I presume the timer stops it charging after 10 or so hours. Is it part of the charger, forklift or completely separate. Might be some milage in bypassing it if you can.

[cornish wood burner]

If you need to use the forklift I suppose you could charge the cells in groups to suit what charger you have. That is presuming you can access the cell links. The odd number of cells you have left can be charged with some already done. Keep the charge rate low then if you can. Remember cells gas when charged so always turn off at the mains first.

[richy_B]

I am pretty sure the charger isn't the original as its a 'Legg'. It states it is for charging 18 batteries at an initial 80amps so the fact I have 20 pretty much confirms it is not the exact match. It seems to have worked OK the last 10 charges though.

[Chippy]

The mercury fuse you mention is a flow switch, there will be some terminals at the bottom of this and when the mercury touches these the circuit is made, try turning this at different angles to see if this cures it.

[richy_B]

Still not worked this out. Checked the socket - Good. Checked the continuity of all the wires in the charger - Good, nothing 'seems' out of place. Checked all the fuses - Good. Checked the forklift batteries which are reading 38.9V. As a 40V system obviously they are low but this makes sense as I was trying to put it on charge due to the forklift becoming sluggish.

 

Would the charger not work if the battery voltage is too low?

[cornish wood burner]

Charger should still work with a low battery voltage. Have you a socket on the forklift you plug into? Check this for connectivity to your battery. If you have a plug socket arangment how many wire are there? Can you bypass the timer? Presumably the mercury switch kills power through the timer. Small diagostic hint for you if needed. If you check fuses,switches etc with power on, any open circuit will have voltage across it. Sometimes poor continuity will only show when under load.

 

Be carefull do not get complacent. Probably no RCD on your 16A /32 A socket

Edited October 2, 2014 by cornish wood burner

[richy_B]

Good tips, thanks. I fear this maybe a long battle yet...