I have a friend in Ohio with this as his problem… his son drives the GEM and is in school…
Just got Gem from the shop a couple of days ago. Asked them to check the brakes and electrical. The told me I had a bad charger and replaced it. Got it back. Seem to be running fine. My son drove it a 4 miles to soccer practice. Said it started to go slower and slower then stopped.(90% CHARGED) I got in and it went for about a mile at 5-10 MPH. Then I got a 15 code(Low voltage) and nothing. Turn everything off and breaker and went a little further. Did the same thing. Charged at a friend ice cream shop for about 20 minute and got almost home until I hit the hill to my house then Shut down with code 15. Finally got home with a tow. All batteries were at 12V or very close. any ideas?
Just based on the symptoms, I’d strongly suspect a battery problem. Voltage isn’t the most reliable test for battery health in my opinion. I think I’d test specific gravity AND voltage after charging and after running it for a bit.
I’d bet he has one or more batteries that are dying.
I’m assuming the batteries are FLA and not Gel or AGM or something more exotic like Lithium. W/ FLA you can remove the battery caps to test Specific Gravity. With other technologies, you can’t and are limited to simple voltage testing OR using a load tester.
===Without a battery load tester===
I’d complete a charge cycle (repeated a couple of times without driving to make certain the batteries SHOULD BE 100% charged) and then read the specific gravity using a simple SG gauge available at any auto parts store. Getting a specific numeric reading is best but even the “floating balls” version is OK. I’d test the battery voltage at the same time and record the results. I’d expect the SG to show 100% charged at this time for each cell in each battery along w/ voltage of at least 12.5 or so. You’re looking for consistency among all individual cells and six batteries. If either voltage or SG is “off”, you’ve found the culprit. All it takes is one “bad” cell in one battery. Often SG will show something wrong with one cell when total battery voltage appears OK.
I’d then drive the car until the BDI showed it was weak (SOC of 70% or so) or something else happened (e.g. turtle mode, error code 15). Once I got home BEFORE charging the cart, I’d retest both the SG and voltage. In my experience one or the other of these will show a problem w voltage for one or more batteries or a low SG for one or more cells.
== With a battery load tester ===
Me personally I’d rather use the tried and true method I described first. Automotive load testers are intended for testing auto batteries which are designed to provide high-amperage; short duration (i.e. starter motors) and not deep-cycle batteries which are designed to provide consistent power over sustained periods of time.
Purchase a battery load tester (they’re not too expensive) at an auto parts store and test the load on each individual battery after charging completely. Be sure to follow the directions on the load tester regarding how long to depress the “load switch” before taking a reading. The load in the unit can get very HOT in use (I’ve seem them catch on fire!); especially if you load the battery too long!
Then he’s probably limited to only voltage testing. I’d charge it a couple of times to get it fully charged and read the voltage. Driving it until it has a reduced charge. Then another voltage reading and see if one is “off”. Fully charged or after running down I’d still expect them all to be within a few fractions of each other (e.g, all at 12.4 to 12.6 fully charged or 11.8 to 11.9 when run down). If one is bad, that will be off significantly (e.g. fully charged 12.4 to 12.6 except one is 11.7 OR after running down 11.8 to 11.6 except one is 10.2).
Incidentally I’d also check all the batteries for terminal corrosion, loose connections or “unusual appearance” (frayed or broken jumpers). Anything that might put additional resistance in the power circuit and thus lower the voltage. If everything else seems good I’d [U]carefully[/U] power off the master switch, remove each jumper cable, polish up the connections on the cable end and battery terminal, verify the cable crimps are solid, visually inspect for broken stranded wires, reattach and spray w/ battery corrosion protector.
Before taking it to the shop(Gem Dealer), the batteries were good. No noticable problem. I had a problem with power one day but it went away. Drove it for weeks afterward. My son turn 16, so I thought I would have it check out since he would be driving it to school(the car sat for 9 years, only had 42 miles when I bought. put in the recommended batteries and 1200 miles later everything was good). General question, if the batteries show 100% charged, should the batteries be good? The dealer said the charger was bad and that could have caused my earlier problem. The dealer replaced the charger and two days later this problem occurred. After showing a full charge the each battery shows only 11.9-12.1V. The batteries are 15 months old and are NAPA part number 8271 which is a GEL group 27 made by Dekka.
In general group 27 batteries are not up to the task. Group 31 is what is recommended for GEMs. Also don’t think 11.9 to 12.1 is right for “fully charged”.
[quote=ARandall;21340]In general group 27 batteries are not up to the task. Group 31 is what is recommended for GEMs. Also don’t think 11.9 to 12.1 is right for “fully charged”.
Al[/quote]
That might be my mistake, I believe I have group 31. Colorado Bob recommended the battteries.