Golf Car BATTERIES at SAMS?

Re: Golf Car BATTERIES at SAMS?

Charge the battery bank until the cells are bubbling (basically a light equalization). Let the bank set for three hours (no load/no charging) for the electrolyte to fully mix in the cells (and the batteries to cool to room temperature).

Then measure the voltage and the specific gravity (and log the results).

That will be "full charge". Monitor (and log) the battery conditions over time and you will be able to ensure that you are fully recharging the batteries (not deficit charging). And any changes will be the results of aging, temperature, and potential problems (bad cabling, failing cell, etc.).

At this point, you need to create your own "full charge" voltage/s.g. chart. At the best, the charts that are out there are only estimates and/or the "ideal" battery. You now need to compare them to themselves.

At best, resting voltage is just an estimate and not very practical to use on a bank that is constantly being cycled (disconnecting the bank and resting for three hours is usually not very convenient).

-Bill

Re: Golf Car BATTERIES at SAMS?

The problem is that batteries are not ideal--and trying to "accurately" "nail" the battery bank performance is probably not worth the effort.

The typical battery would probably lose 25% of its charge over the period of several months (AGM's probably 2-3x longer). I would guess you are recharging your bank every day--so long term losses due to storage should not be an issue.

A battery monitor does something that is very hard for a person to do... Totalize the Amp*Hour taken in and out of the battery over time. It would be like looking at instantaneous fuel flow or MPG and trying to figure out the long term gas mileage--not easy to do accurately.

Basically, you tell the Battery Monitor the estimated bank capacity. And the more complex ones you can program in factors that affect capacity (such as Peukert factor--where the higher current you take out, the less efficient the battery). And the Battery Monitor "resets" back to 100% when the battery "is full" (recognizes the termination of a full charge based on current drop and charging voltage).

Does the battery monitor give an "optimistically" accurate view of the battery capacity (your battery is now at 82% capacity)--yea... But it is more accurate than a DVM and the real time numbers available for a sealed type battery (you cannot access the electrolyte to measure state of charge).

Other than a few points (75% state of charge--long term storage causes sulfation if below ~75% SOC; cycling a battery very often below 50% SOC will quickly age it; cycling below 20% SOC will run the risk of permanent damage to one or more cells)--knowing 84% vs 88% (other than as a relative term) is just too much to expect from a bank that is not setup with laboratory style monitoring.

If you are "measuring" within 5-10% of the "true SOC" (using your own baseline)--you are probably doing well.

-Bill

Re: Golf Car BATTERIES at SAMS?

As long as you charge them before they get below 80% state of charge and get them above 90% SOC--then they should last pretty well...

When I have storage batteries that I need to keep charge but don't have a "nice" charger with float... I just take a lamp timer and set it to turn the charger on one hour per day... Keeps the batteries charged but does not "boil them dry" (my usual problem with the standard trickle chargers on car batteries.

I am sorry--I don't try to keep track of everyone's back-story. There are just too many posters here--and if I answer wrong because I forgot or mixed up a couple histories--then I can cause more confusion.

-Bill