Battery Forensics...Cover Me, I'm Going In

[kellybell]

:-)

[JohnnieB]

Originally Posted by Desert Bill

Well after my 25 minute jaunt and recharge...2 hours, green light, fully charged.

WTF? Have I been on a battery 'Magical Mystery Tour'?

With a side trip to the Land of Oz tossed in.

The battery voltages appear to be in the ballpark.
The excessive water consumption appears to be due to the charger staying on too long.
Sometimes the charger shuts off normally, sometimes it doesn't.
I have a fairly reasonable understanding about how the charger works and considerable troubleshooting skills, but why the charger does one thing some of the time and acts differently at other times is still a mystery to me.

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When you connect the charger to the cart, do carry the the charger to the cart, or do you drive the cart close to the charger?

I'm wondering if there is a crack in the PC Board, or loose/corroded connection, and moving the charger might make/break contact.

In the single picture I have of a Western charger, the is a socket mounted 28-pin IC on the PC Board just behind the 5 LEDs. I've had socket mounted ICs and cracked PC Boards do all sorts of weird things before.

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If the charger continues to misbehave, I'd replace the board, or replace the charger with a new DPI 42V unit.

[Desert Bill]

I am beginning to think this was a water level related issue. Over the last 4 days, cart has been charging in what I would consider a normal time frame...if there is such a thing. Although I have always kept batts 1/4 to 1/2 inch over the plates, it appears now that more is required. After charging I let the spring operated water fill bottle do its thing. Not adding much water whereas before I have added to as much as 15 out of the 21 cells...as much as 1-1/2 gals over a 24 hour period.

Perhaps a minimal water level, and the required longer charge/gassing times contributed to the additional water loss.

JB, to comment on your question...charger stays in same position. I drive the cart near it and plug in. You have been a consistent, great advocate to me with regards to this issue. I understand that diagnostics over the internet are challenging...but the summary of all comments/suggestions can sometimes lead to a resolution. Many thanks.

[whizzo]

weird things do happen....but some times these weird things aint so weird at all.

These automatic chargers can be fooled...they are not all that smart....some of these golf cart chargers as far as smart chargers are concerned are dumb as dog $#@!.
Even the best smart chargers work bassed on what they see comming back up the charger cable.

Have you checked that the contacts on both the charger plug and the socket in the buggy are clean, firm and making good contact...and for that matter all the battery cables.

Here is a senario that may occur...dirty contacts on charger connection....charger plugged in..might take a while for sufficient current to flow for the charger to realise the battery is there....OK apply charge voltage.....small current flows...as contacts heat up and current burns the oxide off...more current flows.....battery charges current reduces as normal...and so on....if the contacts are not good and it is an electronic smart charger.....it may not be able to clearly see the battery and may persist with a higher charge rate or continue to charge longer than needed...thus the gassing.

All speculation of course.

It is also known that batteries, particularly those left idle for a time or just old can develop charge resistance....this is argued as a result of sulphation.
They fail to accept full charge current initially....as the charge process progresses (conversion of sulphates), the charge resistance reduces and normal charge rates resume.....then decline as normal as the battery charges.


Then there is the issue of the batteries becomming unequalised..for variuos reasons.....these are big packs with lots of cells and no two batteries are identical.
when the batteries become unequalised, the standing voltages will be different....thus the different batteries and different cells will charge at different rates regardless of the current flowing being the same.
when there is a large series pack, the battery that is charging (chemically converting) fastest will then tend to be over charged, gass more and require more water

So it is recommended practice to equalise batteries particularly in large series packs from time to time....particularly those that are not regularly loaded or that sit idle.

if you are driving your cart regularly..for decent distances and not pissing arround....and then give the batteries a good solid long charge ( decent amount of current) to fully recharge......this will tend to equalise the batteries and reduce sulphation.

Trojan document that even new batteries need to be cycled a few times to come up to full function if they have been idle.

there is a good case for seperating out the batteries into either single 6 volt units or to 12 volt pairs and charging and cycling them individually with a good modern charger of adequate capacity.

hope this helps.

cheers