Only 8 amps out of Power drive 2 charger

[Khaosz]

I bought a used 2007 DS model Club Car that came with a used power drive 2 charger. I fully understand battery charging because a I am a retired Navy nuclear submarine electrician that maintained the subs batteries. But, we did manual charging using DC generators. So, I my understanding with an automatic charger, when I plug in the charger, the charging rate should go to at least 13 amps after a few seconds and controlled by the OBC. My charger is only putting out 8 amps and I tested on another club car to verify it was the charger, and it only put out 8 amps on the other cart. I did the rectifier test on the charger and it appeared to pass and the transformer is putting out greater than 48 volts. After I did this test, I connected the charger and it went to 12 amps, then oscillated and steadied at 8 amps. I ordered a new rectifier thinking maybe the rectifier has good readings when cold but fails at operating temperature.

I am concerned because I know the capacity of my batteries is going to suffer if I do not get my charger working correctly, I need that 13 amps to knock the sulfates of the battery plates.

Any advice or am I on the correct path?

Ken

[OLD MEC]

Have you checked the Lester Electric site for info or called the phone number 402-477-8988? Also in my area near ocean we get lots of high resistance at charger plug and some times in charger output cable or plug in connection itself? Do these happen to be new batterys or borderline condition older batterys? In both cases it possible for the OBC to not send message to give MAX charge rate, and might apply to other cart used for test as well?
For you wouild like additional info on OBC's see DR Bob forum site as he has done in depth articles on OBC functions.
In any case keep forum posted with results as it helps us all.

[DOOmsman]

Just thinnen have you verified the amperage with an external
meter??

[Khaosz]

I have tested the charger on another cart and got the same results, so I am pretty confident it is not the OCB. The amp meter is working fine so I am sure it is not the ammeter. Thanks for the website advice, will check it out.

[OLD MEC]

My previous post had incorrect name its ( DrBob ) in forum member list? Sorry
Look under "How Does 48 V 2001 Club Car OBC Function"

[dougmcp]

I don't think you need the amperage to "knock the sulfates of the battery plates". As the charger gets close to full charge, the voltage increases as the amperage drops and it is the higher voltage that boils the electrolyte and stirs it up. I would take a volt meter and check the voltage of the pack near the end of the charge cycle, if it is above 57.6v you should be getting the overcharge/equalization you require.
IMO, stratification doesn't really occur in a golf cart and generally doesn't require much equalization. The only time you can really get stratification is if it has been sitting for months.

[Khaosz]

Here's the deal, I placed my charger on another cart and got the same symptoms, I used that carts charger on my cart and saw greater than 13 amps. I have illuminated the cast and isolated to the charger. I know the 8 amps is killing my batteries because the capacity is low. I have only had the cart for 6 months and could play 36 holes and not see the battery light, now I play 9 holes and see the battery light. This means the battery is not getting a good charge. The battery is just below 48 volts fully charged which indicates a low charge, it should be above 49 volts. I have been doing battery charges for years and understand batteries, it is the charger I am having issues with.

What could cause my charger to put out only half of what it should, the rectifier seems to be a good culprit but I am just not sure.

[dougmcp]

Yes the rectifier could be the culprit.
Less than 48v means you are starting out with less than a 50% charge on your batteries, a fully charged pack should be about 51v. If it has been doing this for awhile they are now probably sulfated to the point where you are getting reduced run time and reduced ability to charge.
Batteries will sulfate at anything less than 90% charged.
Just a few questions:
How old are the batteries?
If you have less than 48v after a "full charge" is the charger shutting off automatically?
Have you load tested them or hydrometer tested?

[Khaosz]

the batteries are about 2 year old
the charger shuts off auto
I am going out tomorrow to find a cheap hydrometer to get a specific gravity reading

[dougmcp]

With any luck you will find a bad cell and the root of the problem.
Maybe you could borrow someone's 48v CC charger and see if it works on your cart to eliminate the OBC as suspect.