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Discussion Starter #1
Hi,
I have an older hydraulic scissor lift that is operated by rechargeable batteries. I put new batteries in it about 10 months ago and the lift has been outside for most of that time. It has not been used very much. I am currently having trouble getting it to operate. When I try to operate it, it just makes a clicking sound. But, it won't do anything. In the past, it would stop operating for a while and then just go back to working again. I bought this lift used a long time ago and have never known the brand of the lift and have never had a manual to go with it. It has been a great lift, but I just need to figure out what is causing it not to operate now.
 

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dmxtothemax, I haven't put a meter on the batteries yet. I will try to do that tomorrow. I had the charger plugged up yesterday and according to the gauge on the charger, the batteries seemed to be charged up fine. But, I will double check them with a meter. It has done this in the past, but seemed to just go back to working on its own. I'm not sure if a relay is coming and going or not. Thanks for your advice.
 

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trouble shooting is not hard. If the hyd won't run, what makes it run? Is it a solenoid? What's the voltage at the solenoid, what should it be? Keep working backwards from there.
 

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Discussion Starter #6
backstay thanks for your reply. It appears that the solenoid is clicking, but the motor is not running. How would I know what the voltage should be at the solenoid since I don't have any paperwork on this thing? Thanks again.
 

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sparkywannabee, I'm not sure what brand or model that it is. I bought it used a long time ago and have never known what the brand or model is. It was painted yellow when I bought it, but I'm not sure if that was the original color or not. I bought it from an equipment rental place. If it does turn out to be a bad motor, do you have any idea how much a new motor would cost? Thanks.
 

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The usual clicking is the solenoid// relay cycling in and out of contact.

The batteries are the problem.

You screwed up.

Never let your lead-acid batteries go that long without being recharged.

They will ALWAYS internally discharge.

This is inherent to wet cell batteries -- in particular.

To top that off, scissor lifts ALWAYS have conducting solutions coating all over the battery tops.

You need more than a bare bones charger to bring them back up.

There are a lot of videos on battery 'games' on YouTube. Take a peak.

Your terminal posts are also in a serious need of PM.

Pull all cables -- clean -- re-secure. You're dealing with lead -- not copper.

&&&

Failure mode #2. You've got a dead spot on the armature of your DC pump-motor.

Failure mode #3. You've worn through your DC to commutator brushes. Yes, they wear out.

I'll bet that you've never, ever touched them.

That also goes for the prior owner.

So now they make feeble contact. The lift gets 'twitchy.'

Solution: keep the motor -- replace the brushes. They cost peanuts and for such a motor are easy to swap in the field.

&&&

A robust -- high end -- battery charger can be used in "motor starting mode." Yes, these are the roll-around chargers you've seen at service stations across the nation.

You can hook that puppy up and then crank the lift -- just up and down, please.

This step eliminates the batteries as an issue. ( Leave them hooked up )

For ANYONE with a scissor lift -- get such a charger -- and never leave it at the job.

Such chargers make it possible to entirely recharge your scissor lift -- during the work day -- during lunch and breaks.

So, you're NOT dependent upon having your critical machine getting a charge over night.
( When your machine gets unplugged so that the other guy's lift gets a charge. )

Such chargers can be 'buddied up' -- if you know how to wire DC circuits -- so that you have either 24 VDC or paralleled 12 VDC charging systems.

If you tinker around, you can convert a 12 VDC charger into a 24 VDC charger.

Yes, play with a transformer swap out // re-wire a center-tapped transformer.

:thumbsup:

Do relabel such a modified charger. ( I'd go with a two position relay, myself. )

I leave the details up to you. :whistling2:
 

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Just went through this in the summer on an old lift. Had the same issues of just a solenoid clicking. Instead of scraping it after failed attempts with some new parts, it was decided to spend a little more money. Called the service tech and he came out. It was a pleasure watching him tighten the battery cables another turn and a half. Fixed!

The tech said these lifts are super sensitive to voltage and to keep the cables cranked down.
 

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Discussion Starter #12
Thanks Telsa and Rns. I really do appreciate all of your information. I am going to check the cable connections and the voltage on the batteries tomorrow and hopefully find out what I need to do from there. Telsa, if its determined that I need to get the batteries charged back up properly, do you know where I could take the batteries to have them recharged since I don't have one of those super chargers that you are talking about? Thanks again.
 

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Is there not an onboard charger? most lifts are 24 volt and use 4-6 volt golf cart batts. If you don't have one go to ebay and get one. You need to charge batts and check water at least once a week wether you use it or not.
 

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Discussion Starter #14
sbrn33, thanks for the information. My scissor lift is set up just like what you are talking about. It does have the onboard charger for the four 6 volt batteries. I just thought that Telsa meant that I needed a super charger to get the batteries back up to where they need to be, since I haven't kept them charged up in a while.
 

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sparkywannabee, I'm not sure what brand or model that it is. I bought it used a long time ago and have never known what the brand or model is. It was painted yellow when I bought it, but I'm not sure if that was the original color or not. I bought it from an equipment rental place. If it does turn out to be a bad motor, do you have any idea how much a new motor would cost? Thanks.
You said it has stopped working intermittently for a while, this tells me you have a bad spot in the motor. Not a good idea to let any batteries go dead for extended period of time. You check them with a battery tester, put some load on it. JLG, and I am sure Genie as well, have excellent manuals online. They had different motors they used, Ohio, Leeson etc, you will have to get a number of the motor and prolly find a new one, surplus, on Ebay for under $500. I would just get a new motor.Keep the pump. There will be a plate on the lift, the serial# is critical when you look up schematics online. Also, bad idea to keep it outside if you can avoid it, Georgia winters not as bad as Ohio, but the elements are hard on hoses and such.
 

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sbrn33, thanks for the information. My scissor lift is set up just like what you are talking about. It does have the onboard charger for the four 6 volt batteries. I just thought that Telsa meant that I needed a super charger to get the batteries back up to where they need to be, since I haven't kept them charged up in a while.
No you don't need that. Plug it in and check the voltage. It should be around 28 volts or so when charging. Water is a big deal.
It is probably not the charger or batts but you never no and it is easy to eliminate them as a problem. It doesn't hurt to redo all those connections.
 

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Thanks Telsa and Rns. I really do appreciate all of your information. I am going to check the cable connections and the voltage on the batteries tomorrow and hopefully find out what I need to do from there. Telsa, if its determined that I need to get the batteries charged back up properly, do you know where I could take the batteries to have them recharged since I don't have one of those super chargers that you are talking about? Thanks again.
The lift should have a charger on it.
Unless your batteries are bottomed out you shouldn't need any "super" charger.
 

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Discussion Starter #18
sparkywannabee, thank you. When you say that it has a bad spot on the motor, what exactly does that mean? Do you mean it has a short in the windings? Or, do you mean that the brushes need to be replaced?
 

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sbrn33 and A Little Short, thank you. I will load test the batteries tomorrow and see what kind of voltage that I'm getting. I will also check all of the battery connections to make sure that there is not corrosion build up somewhere and then tighten them down good.
 

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sparkywannabee, thank you. When you say that it has a bad spot on the motor, what exactly does that mean? Do you mean it has a short in the windings? Or, do you mean that the brushes need to be replaced?
More likely bad insulation, scissor lift motors don't get a lot of actual run time, rental places don't hang on to them too long, brushes last forever. I have worked on big DC motors that ran 24/7 and did'nt have to change brushes for 10 years.
 
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