View Single Post
 
Old 05-09-2011, 09:26 AM
ajbrown's Avatar
ajbrown ajbrown is offline
Sage
Join Date: Oct 2009
Location: Mallory Square (9 months/year), TBD the rest
Posts: 2,641
Thanks: 12
Thanked 18 Times in 9 Posts
Default Sorry, this is long and boring....

Of course it is boring, what did you expect, it is about golf cart batteries for goodness sake

I have only owned electric carts since buying a place in TV in 2007 and knew zero when I got my first cart. With the first cart, when the range decreased I looked at the batteries and said. I guess I need a new set. I will never know the exact reason I needed a new pack, did I discharge too much, did I have a bad battery, etc? They were three years old, so I just forked over $725+ for 8-6 volt batteries.

This time I know more than a fifth grader (but not much) from reading sites like this or:
http://www.buggiesgonewild.com/
http://server1.buggiesunlimited.com/...forum.php?f=11
It is amazing the number of threads that address these issues every day. Range, how deep to discharge versus life, testing, etc. Please understand, I am not an expert, just relaying my experience. When I use words like “my thinking is” you could easily replace them with “my guess is”.

Back to my issue. I have one bad battery and five that have the potential to go 25+ miles without discharging the pack too greatly. I am headed north soon and I sure do not wish to buy a new pack for $625 and as importantly I have sister-in-laws en route.

My Dad is currently rebuilding a CC to hold 8-6 volt batteries so he has a few 8 volt batteries in the garage and offers one to me. FYI, my Dad is smarter than a fifth grader and most anyone else I know and at 79 years young to be stripping a cart down to the frame, moving batteries, designing a space for two new batteries, adding a lift kit, rewiring the entire 12 volt system, etc. is inspiring IMO .

I get my Dad’s battery home and see that it is stamped E5. Ok, beggars cannot be choosers, but six years old Dad? It has 8.01 volts. I drive the cart around for a bit to discharge the other batteries, then I replace the bad battery with Dad’s in the pack. After a full charge cycle, the five are holding voltages of 8.38 – 8.43, about 90%. Dad’s battery is only at 8.11

My thinking is that the charge cycle is too short for this battery as it starts out with a much less voltage than the other five. At this time I do not even know if this battery can hold a charge. I decide to try something I have never done before by charging that battery individually. I borrow a friend’s 12 volt Diehard charger and refer to some threads on buggiesgonewild.com. It is my goal to charge this battery by itself to see if it can hold a charge over 8.40 volts. Some things I knew or learned:
  • It is ok to charge an 8 volt battery with a 12 volt charger.
  • You do not need to remove the battery from the pack.
  • You can check the voltage while charging
  • You should charge it with lowest amp setting on the charger. This charger had a 2 amp setting
  • Set the charger to manual
  • Monitor for heat, check the wires, check the battery case (do not just let run while you go to happy hour!!)

In my case the charger and charger wires got somewhat hot. Nothing that was worrisome. The battery case never had a heat issue. My goal was to get the battery up to 10+ volts during charge. When I started I would only charge for about 30 minutes. As I got more confident, I allowed to run for an hour while I monitored. I did not document how many times I did this, but eventually the battery was reading 10 volts while on the charger. My guess would be around 3 hours of charging. In the end, I never could get the battery to hold more than 8.21 volts (less than 70%), so this is not going to be a solution for me.

I now wonder if battery dealers have used batteries. It makes sense to me that they should, as most folks replace a pack like mine and there are 5 batteries that have some value left. I call the two local big name battery folks. Battery Boys was one of them and they had some in stock. They charge $50 for the used one if I bring my dead one to their shop. Terrific guys, but as I mention to Dave, I question the intelligence of anyone that selects black as a shirt color for a business in Florida. Black is for solar collectors, not guys working outside . Battery Boys are now on my short list, good guys, good business. I found them on TOTV and the experience was all positive.

I drop the used US Battery into my Trojan pack and head out for a ride. This is better already as six batteries are sharing the load. I can see the difference in the battery meter on the dash as heavy load does not move the needle hard left. I allowed the new battery a couple of charge cycles, then I took numbers as I always do:

After charging and resting 9 hours:
8.42, 8.45, 8.46 (used), 8.42, 8.46, 8.41, Total: 50.62
Immediately after 11 mile ride
8.31, 8.32, 8.29 (used), 8.31, 8.36, 8.32, Total: 49.91
Immediately after additional 14 miles (total 25)
8.11, 8.11, 8.07 (used), 8.10, 8.15, 8.12, Total: 48.66
Rest 45 minutes after ride
8.17, 8.18, 8.17 (used), 8.16, 8.21, 8.16, Total: 49.05
Now I have a pack I can test the Battery Life Saver on……..

Last edited by ajbrown; 05-09-2011 at 12:49 PM.