Solenoid questions

[Kliner17]

Just bought my first cart. Needs alot of TLC but I'm excited about resurrecting it.

I was wondering if you all could help me out. I got the cart home, charged it, then drove 3 feet before it started shuddering then ultimately stopped. Checked batteries and I'm getting 37v then 36v with accelerator pressed. I'm thinking it's the solenoid.

My question is, I cant find a MZJ200d anywhere can I upgrade to a 400 with stock controller? After I do so do I need to change the fuse from 250 to 450?

I'll search for install instructions but if anyone has a quick link I'll appreciate it.

2011 HDK cart
2015 batteries
36v

Thanks ladies and gents!

[JohnnieB]

Originally Posted by Kliner17

Just bought my first cart. Needs alot of TLC but I'm excited about resurrecting it.

1. I was wondering if you all could help me out. I got the cart home, charged it, then drove 3 feet before it started shuddering then ultimately stopped. Checked batteries and I'm getting 37v then 36v with accelerator pressed. I'm thinking it's the solenoid.

2. My question is, I cant find a MZJ200d anywhere can I upgrade to a 400 with stock controller? After I do so do I need to change the fuse from 250 to 450?

I'll search for install instructions but if anyone has a quick link I'll appreciate it.

2011 HDK cart
2015 batteries
36v

Thanks ladies and gents!

1. The shuddering typically indicates insufficient amps being delivered to motor and your 5 year old batteries are beyond normal life expectancy.

At 37.0V they are less than 70% charged. See attached SoC chart.

Measure between the controller's B- and B+ to see what the voltage being felt at to controller actually is and between M- to B+ to see what is being applied to the motor.

2. A 400A rated solenoid will only pass what the controller will pass and the controller will only pass what the motor is able to draw. The fuse is determined by the controller's amp ratting, ANN250 for controllers ut to 400A and ANN400 for controllers over 400A.

[Kliner17]

Originally Posted by JohnnieB

1. The shuddering typically indicates insufficient amps being delivered to motor and your 5 year old batteries are beyond normal life expectancy.

At 37.0V they are less than 70% charged. See attached SoC chart.

Measure between the controller's B- and B+ to see what the voltage being felt at to controller actually is and between M- to B+ to see what is being applied to the motor.

2. A 400A rated solenoid will only pass what the controller will pass and the controller will only pass what the motor is able to draw. The fuse is determined by the controller's amp ratting, ANN250 for controllers ut to 400A and ANN400 for controllers over 400A.

Great info, really appreciate it. I should.mention I picked the cart up when it was working, the guy said it had an hour charge on it. Drove it around for 10 minutes and it felt great. Got it home, batteries died, so i put it on the charger for 2.5 hours hence the 70% charge. After charging that's when the shuddering happened and it quit. After 5 min and several times switching key on/off something clicked and it moved 10 feet then stopped again.

After the 2.5 hour charge all batteries read fine on the meter. I measured the controller and is getting plenty of juice. In addition, I removed all + and - terminals, cleaned them and applied corrosion preventative.

Any other thoughts?

[PingEye3]

Give it full charge, up to 12 hours. Then start any troubleshooting with fully charged batteries. BUT, I just noticed that they are 2015 batteries. Most likely need to be replaced. A hydrometer will give you the best check on the health of those batteries.

Battery Story
I had a member who's cart wouldn't make it halfway thru the first hole before dying. When I checked with a voltmeter, all six batteries read above 8.4v or about 90% charge. Checked with a hydrometer and not one cell would even raise the float off the bottom of the hydrometer. All were dead even though showing good voltage.

[Kliner17]

Originally Posted by PingEye3

Give it full charge, up to 12 hours. Then start any troubleshooting with fully charged batteries. BUT, I just noticed that they are 2015 batteries. Most likely need to be replaced. A hydrometer will give you the best check on the health of those batteries.

Battery Story
I had a member who's cart wouldn't make it halfway thru the first hole before dying. When I checked with a voltmeter, all six batteries read above 8.4v or about 90% charge. Checked with a hydrometer and not one cell would even raise the float off the bottom of the hydrometer. All were dead even though showing good voltage.

Will do, thank you!

I also just saw the controller says 300a but the solenoid is 200. Could the guy that I bought it from just slapped a 200a solenoid on it before selling or does it even matter?

[Kliner17]

Another question... do I need a resistor on the solenoid?

[JohnnieB]

Originally Posted by Kliner17

Will do, thank you!

I also just saw the controller says 300a but the solenoid is 200. Could the guy that I bought it from just slapped a 200a solenoid on it before selling or does it even matter?

I'm not familiar with HDK golf carts, but the stock solenoid on a EZGO 36V PDS cart was rated at 85A, so the 200A was better than stock.

A solenoid's amp rating is for continuous amps and the contacts will pass several times that for short periods of time and a 36V PDS cart usually only draws above 50 to 75 amps for short periods of time.

Of course, the 85A solenoid was marginal, at best, for the 300A PDS controller, but it only had to last for the warranty period and the bean counters figured replacing a few under warranty was cheaper than installing a higher rated one to start with.

-------------
Overkill is underrated for golf cart batteries, cables, controllers and solenoids.

[JohnnieB]

Originally Posted by Kliner17

Another question... do I need a resistor on the solenoid?

Maybe, maybe not. Depends on which drive system the HDK has.

[Kliner17]

Originally Posted by JohnnieB

Maybe, maybe not. Depends on which drive system the HDK has.

I believe its a sepex drive. I was told evolution bought hdk so alot of parts are universal

[cgtech]

Solenoids have 2 different amp ratings, one is "continuous", and the other is "intermittent". For example, the yamaha (jw2-h1950) solenoid was rated for 225a, but that is only half the story. (And it was a really good one from the factory). If you dig deeper, into solenoid ratings, the story changes. The yamaha one could handle 225a "continuous", and 600a "intermittently". A golf cart doesnt always use all the amps a controller is rated for, and there is no way to make it do so either (unless you park it against a wall, hold the throttle down, and the wheels dont spin). A 400a controller doesnt "pump" 400a into a motor, it just allows the motor to use up to 400a from the batteries. The motor only uses as many amps as it needs, based on its rpm. When sitting at zero rpm, it can use lots of amps, all the amps the controller can deliver, but as soon as rpms increase, the amps it can use drop very quickly (we can call that "intermittent", as soon as rpms increase, load drops). Most typical carts use between 75a & 100a when cruising down the road at top speed (we can call that "continuous" load). As you can see, a solenoid rated at 225a "continuous" clearly covers those demands as well.

I hope this was clear enough to help you understand your "solenoid questions".