Battery issue

[shadowman]

yes thats a huge reason its done......more power and runtime........................

[trigger1937]

Shadowman,...It has been awhile since I posted to this thread and I'm still puzzled about the "Runtime" issue. I read another thread where a Golf Course Manager indicated that they had given up on the CC 12 volts system because the Carts would not run a full day and many would die on the golf course in the middle of the 2nd round. They got tired of this and swapped them all out for the 8 volt system that they had a lot of experience with. My own CC dealer is telling me he spends most of his time now working with local Golf courses just swapping out batteries and making the conversion back to 8 volts just because of the run time.

I had done the calculation a week ago and both the 8 volt and 12 volt systems contain the same number of total "2 volt" cells (24) and the cells from Trojan are rated for 150 Amp/hrs. The total power is calculated by muliplication of the Volts X 150 Amp/hrs. Therefore both system are supposed to have the same total power.

If we went one step further and switched back to 6 volts, it would take 8 batteries with 3 cells each and there would still be a total of 24 cells at 48 volts. The only possible change would be if the 6 volt units came with more Amp/hrs rating.

I also mentioned in some other post that 2 years ago I have purchased a set of "Energizer" batteries from Sam's club for another golf cart and they only lasted 2 years before failing. Today I checked again at the store and this time I noticed that those units are only rated for 100 amp/hrs. That is 1/3 less than the Trojans,.. and that is why they cost less. My question for you is,...for any of the 6, or 8, or 12 volts systems,...if all them have the same power capability what would make them run longer. When the batteries are in series all 24 cells have to be at peak voltage and charge to get the max Amp/hr current out of them. The weakest cell in the series will define the max current you can get and voltage drop in each battery (due to load) limits the max voltage. The resulting total volts and current defines the actual power delievered.

[Stevegrmich]

@trigger:

You are correct . . batteries connected in parallel give you the same voltage as a single battery, but with a Ah and current carrying capacity equal to the sum of the capacities of all the batteries.

Batteries connected in series will give you a voltage equal to the total voltage of all the batteries, but the Ah and current carrying capacity of only one.

[shadowman]

trigger i,m not a battery expert and have never done any testing other than jump on carts set up both ways and drive them the exact same places and ways and out of all the battery setups the six 8 volt batteries win hands down now that is until you jump up to 72 volts or 96 volts than your in for a ride.........but i can,t give you a technical answer i have none....can only tell you from my experience and that of others who run their carts that way.................................

[Stevegrmich]

Originally Posted by shadowman

trigger i,m not a battery expert and have never done any testing other than jump on carts set up both ways and drive them the exact same places and ways and out of all the battery setups the six 8 volt batteries win hands down now that is until you jump up to 72 volts or 96 volts than your in for a ride.........but i can,t give you a technical answer i have none....can only tell you from my experience and that of others who run their carts that way.................................

As for rate of discharge of batteries, it is dependent on the batteries "Peukert's" rating . . .

http://www.csgnetwork.com/batterylifecalc.html

ps . . I'm not really this smart . . . I just Google stuff to make me look that way . . . my curiosity drives this . .

[shadowman]

steve thats why i,m so dumb sometimes i never google anything..........................

[trigger1937]

I must really be thick headed,... I have "Googled" this topic for weeks and I'm still not any smarter than before. However, having seen first hand the experience of over 100 Club Car golf carts on my golf course and watched the performance of the 6-8Volt units last about 8+ years,...this is good enough for me. I just hope I can get a few more months out of these 12 volt batts. Three of them seem pretty good, not great, but good enough. One of them has the first cell that won't charge better than in the "White" on my Hydrometer, but the other 5 cells will go up into the green to full charge. The problem is that cell won't hold much of a charge. The voltage of that battery will measure 12.5 because 5 of the cells are way up in the green,..but when it comes to pushing current, that weak cell limits everything. Since my local dealer has been so great to me he is going to allow me to pick out the best of all of his returns and try one more time. As I indicated he is pulling all kinds of batts out of a local golf course and converting them over to 8 volts. He holds the old 12 volt units unit he gets a full pallet or his next shipment of 8's arrives and then the go back. He has no problem letting me search for one that could match the other 3 I have.