Slow EZGO PDS

[csmdew]

After sitting for a couple of weeks (running fine before parked) my ezgo pds model started going slowly, about 1/2 speed so I put it on the charger but was still slow. Added water and recharged but still slow. Used hydrometer to test batteries and this is when it got really strange; first check of a cell showed weak battery, but testing same cell by refilling hydrometer it went to fair and when I did it a third time it went to good; this really makes no sense. Bad hydrometer or bad testing procedure. Could be something else to make it slow down as quickly as it did, like solenoid, sensor, or just the old batteries (6/06).
Thanks

[Cobra,1]

Are you sure on date of batteries? Five years out of cared for batteries would be normal.
What is pack voltage after a full charge after charger shuts off? What is each batteries voltage after a full charge? Need to check specific gravity of each cell of each battery. What is it?
Do you charge batteries after every time cart is used?
Batteries charged every couple of weeks when in storage?

Answer these guestions to help trouble shoot.😊

[csmdew]

Yea, sure of date F05 on napa batteries means jun 2015 and were last set I purchased for my carts. Sold 2 carts and only have this one left. Usually charge at least once weekly unless run to dump site and then is charged as soon as returned. Been a little sickly last 3 mos and got lax on charging. But cart was running fine when parked and then about 2 weeks later no power. Gonna run a volt and load test sometime today. Maybe my hi-speed magnet fell off or just died, will have to check it as well. Will post more when testing done. thanks


should have read 6/05 not 06.

[JohnnieB]

FYI: The electrolyte (roughly 30% acid and 70% water) stratifies as lead-acid batteries sit still, with the heavier acid sinking to the bottom, so a sample taken from the top will have a lower SG than a sample taken from the bottom. Each time you squirted what was in the hydrometer back into the cell, in de-stratified the electrolyte a bit more, so the SG was progressively higher.

Whenever I take hydrometer readings, which is rarely because it is easier to take voltage readings and voltage reading average out the stratification of the electrolyte, I fill the hydrometer and squirt it back in the cell a half dozen time or so to mix the electrolyte before taking a reading.

Also, the electrolyte expands in volume as the battery charges, so if a partially discharged battery is filled to the correct fluid level, it is likely to be overflowing when fully charged. In other words, only add water (distilled only) to fully charged batteries unless the plates are exposed and then just add enough water to cover plates.

[csmdew]

Yea, that's what I did with most cells and only had 1 out about all with a reading at 1275, a few were just in green, most were weak and a few red. Voltage was only 36.2 and I believe when new were close to 39. 6 yrs old so just gonna buy all new and see what happens. Always got the side by side if needed.