Charging Issue on a 2008.5 Precedent with 4-12v to 6-8v Conversion

[mohms]

Hello all, I have a charging issue with a cart I just recently purchased, and I'm hoping I can get some direction as to where to start diagnosing the problem.

When I got the cart, it was a 4-12v system but the owner had already removed the batteries and cables. Everything was corroded pretty bad. Even one of the tie down rods was completely corroded through.

I ended up purchasing 6-8v Trojan "black box" batteries along with a couple new 6 AWG cables and hold downs. I wired everything up and the cart ran just fine. It sat for a couple weeks and I decided I should probably plug it in to give the new batteries a proper charge.

The cart came with a Powerdrive 3. When I plugged it in, the charger immediately pegged out as far as the needle would go, way past 15 amps. It was also humming/buzzing loudly. I thought this was strange, but figured it may be the OBC doing some sort of check, so like a moron I left it plugged in. This was at about 11 PM.

Fast forward to early the next morning. The charger had already switched off when I got to the cart, but the shop was filled with an off gassing smell. BAD. The entire 50'x80' shop smelled. It was clear that something was wrong.

I checked the voltage of each battery, 5 were 8.33 and one was 8.34. Load tested and all were OK. Good, I didn't kill my brand new batteries!

I ran the cart around for 10 or 15 minutes, and plugged the charger back in. Again with the pegged out needle and loud buzzing. Checking the pack voltage with a multi-meter while the charger was running was around 90v!!! This can't be good!

I do have a Powerdrive2 for my older DS that I'm going to try on the Precedent and see what happens. I just need to get to my campground and pick it up.

The problem seems to be with the charger, and not with the OBC. I think, but I'm a noob when it comes to these charging systems. Any ideas on where I should start looking for the problem? Oh, the charger was plugged directly into an outlet that was a mere 3 feet from the sub panel. I don't believe power delivery to the charger to be the issue.

[Frizbgolf]

Sounds like normal operation to me. The charger does a battery check when it is first plugged in to cart to check the state of charge on the batteries, it will cycle on and the needle will peg out, it should then click off and back on again to start the charge cycle. Also new batteries will take longer to charge for the first 15 or so charge cycles. You should never let the cart sit for an extended period of time without the charger being plugged in, the charger will come on and charge the batteries during an extended period of time. And finally it is a good practice to always charge the batteries after every use regardless of how short the use was, this will keep the batteries at optimum charge leve and extend the life of the batteries. If you are noticing a gassing smell check the water levels in the batteries, water should only be about 1/2" above the plates if they are overfilled they will gas and cause corrosion on the connections. Hope this helps.

[mohms]

Thanks for the reply Frizbgolf.

I neglected to mention that after the initial check where the needle pegged out, the charger did kick off momentarily. It then kicked back on and remained pegged out for some time (not exactly sure how long). Is this normal?

When I get a chance to plug it in and monitor it for an extended period to see if the charging amperage drops incrementally, I'll be sure to do so.

Also, water level is good. Thanks again.

[Frizbgolf]

mohms yes that is normal operation.

[mgray70]

The 90 volt part is not normal. Should get up to around 65 volt or so, but not 90.

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[Sergio]

It is also not normal to have only 8.34v after it finished charging, it should have been more like 8.6v+ for new batteries....

Can You post some pictures of your battery compartment showing how the batteries are connected?

I cannot imagine your 90v reading was accurate, your batteries present too much of a load for any charger to be able to maintain that voltage level.

[mohms]

Originally Posted by Sergio

It is also not normal to have only 8.34v after it finished charging, it should have been more like 8.6v+ for new batteries....

Can You post some pictures of your battery compartment showing how the batteries are connected?

I cannot imagine your 90v reading was accurate, your batteries present too much of a load for any charger to be able to maintain that voltage level.

Hey Sergio, I'll get some pictures as soon as I can. I used the attached wiring diagram to wire the conversion.

I'll also get another reading with a different multi-meter to see if the original was off. It was an old meter after all...

[Sergio]

That diagram is the right one, but the common mistakes are:

1 - battery wired backwards.
2 - positive lead from charger receptacle not on pack positive battery post.
3 - additional negative cable by-passing OBC.

[mohms]

Originally Posted by Sergio

That diagram is the right one, but the common mistakes are:

1 - battery wired backwards.
2 - positive lead from charger receptacle not on pack positive battery post.
3 - additional negative cable by-passing OBC.

Thanks for the heads up! I can say that 1 and 2 are good to go, but I'll have to look into 3... I'm not sure where the additional negative cable is.

The attached pic is how the cart looked when I got it. I'm not sure what the black cable with the yellow connector is. It is currently not attached to anything.

[Frizbgolf]

Missed the 90v statement MrGray good catch.