# Re: [EVDL] Golf cart battery capacity (Energizer GC8)



## EVDL List (Jul 27, 2007)

*Re: [EVDL] Golf cart battery capacity (Energizer GC8)*

Hello Jay,

Your voltage vs SOC is close, to be more exact:

SOC No Load Specific 75A 100A 225A 300A
Voltage Gravity

100% 6.37 1.277 5.95 5.52 5.08 4.65
90 6.31 1.250
80 6.25 1.238
70 6.19 1.217
60 6.12 1.195
50 6.05 1.172 5.62 5.09 4.56 4.03
40 5.98 1.148
30 5.91 1.124
20 5.83 1.098
10 5.75 1.073

The amperage load is the SAG voltage. When the load is remove the voltage 
should rise to the no load voltage. This amount of battery voltage SAG or 
Drop is OK as long as it rises to the listed NO LOAD VOLTAGE.

If your battery indicates a certain amount of Reserved Minutes at 75 amps, 
than any battery ampere higher than that will have short Reserved Minutes 
and a lower ampere load shall have a longer Reserved Minutes.

The Ampere Hour of battery is rated at a 20 hour rate or we can say 1200 
minutes. The battery ampere at 1200 minutes is:

Battery Ampere Hour / 20 hrs = Battery Ampere

If your battery is 200 AH, than 200 AH / 20 hrs = 10 amp load for 20 hours 
to 0% SOC.

If you test out a 200 AH battery at a 10 amp load, it is best to stop the 
test at 50% SOC and check the no load voltage and specific gravity

If you test out a battery at the listed 75 amp load at its listed Reserved 
Minutes, than stop the test at 1/2 of the Reserved Minute time which also 
should be about 50% SOC.

Roland




----- Original Message ----- 
From: "Jay Summet" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Sunday, December 04, 2011 5:45 AM
Subject: Re: [EVDL] Golf cart battery capacity (Energizer GC8)


> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
>
> Also, if somebody can double check this chart I made for resting battery
> voltage vs SOC, I wouldn't mind hearing confirmation that I got it right.
>
> Designed for 20 6volt lead acid golf cart batteries:
>
> SOC Batt Voltage V x 20 Specific Gravity (+/- 0.01)
> 100% 6.3v 126v 1.265
> 75% 6.2v 124v 1.225
> 50% 6.1v 122v 1.190
> 25% 6.0v 120v 1.155
>
> (I have just purchased an optical Hydrometer but haven't actually used
> the specific gravity checks yet...)
>
> Jay
> -----BEGIN PGP SIGNATURE-----
> Version: GnuPG v1.4.10 (GNU/Linux)
> Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/
>
> iEYEARECAAYFAk7ba3QACgkQSWJjSgPNbM+R6gCeKbMhhqwVaUped5iF8NAWCEOZ
> LQYAn2O8h7sJ/DhDMdPZ7RTzZG4XHXeJ
> =inxh
> -----END PGP SIGNATURE-----
>
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## EVDL List (Jul 27, 2007)

*Re: [EVDL] Golf cart battery capacity (Energizer GC8)*



> On 4 Dec 2011 at 7:45, Jay Summet wrote:
> 
> > Also, if somebody can double check this chart I made for resting battery
> > voltage vs SOC, I wouldn't mind hearing confirmation that I got it right.
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] Golf cart battery capacity (Energizer GC8)*



> Roland Wiench wrote:
> > Your voltage vs SOC is close, to be more exact:
> 
> Lots of good information, Roland. But it is good to remind folks that
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] Golf cart battery capacity (Energizer GC8)*



> Jay Summet wrote:
> > My understanding was that golf cart batteries are rated at 105 minutes
> > already using the 75 Amp rate? Are they actually rated 105 minutes at
> > the 20 amp rate?
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] Golf cart battery capacity (Energizer GC8)*



> On 4 Dec 2011 at 10:30, Lee Hart wrote:
> 
> > Every battery publishes data on its capacity at at least two different
> > discharge currents. From these two, you can use Peukert's equation to
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] Golf cart battery capacity (Energizer GC8)*



> Lee Hart wrote:
> 
> > A T-105 is a "105 minute" golf cart battery, which means it can supply
> > 75 amps for 105 minutes. That's 75a x 105m = 7875 ampminutes. Divide by
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] Golf cart battery capacity (Energizer GC8)*

> From: [email protected]
> To: [email protected]
> Date: Mon, 5 Dec 2011 20:40:11 -0800
> Subject: Re: [EVDL] Golf cart battery capacity (Energizer GC8)
> 


> > Lee Hart wrote:
> >
> > > A T-105 is a "105 minute" golf cart battery, which means it can supply
> > > 75 amps for 105 minutes. That's 75a x 105m = 7875 ampminutes. Divide by
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] Golf cart battery capacity (Energizer GC8)*



> Hoegberg wrote:
> 
> > Yes. But sometimes it have been hard to find good datasheets /spec that
> > can be trusted.
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] Golf cart battery capacity (Energizer GC8)*

> From: [email protected]
> To: [email protected]
> Date: Tue, 6 Dec 2011 16:45:32 -0800
> Subject: Re: [EVDL] Golf cart battery capacity (Energizer GC8)
> 


> > Hoegberg wrote:
> >
> > > Yes. But sometimes it have been hard to find good datasheets /spec that
> > > can be trusted.
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] Golf cart battery capacity (Energizer GC8)*

Aside from cycle life, I wonder if any manufacturers put out 'calendar life' expectation of their batteries. If one were able to drive 60,000 Km (6,000 cycles), it would take some 3,000 trips (10km there, charge, 10km back) which would take about ten years to do.

Would a lead acid battery really last ten years, and still have 80% DOD? Or would the plates have disintegrated by then?

I take reasonably good care of my pack, but it is at about 65% after 4.5 years, traveling in about the same pattern (4.5 miles to work, charge, 4.5 miles back home). Occasionally I travel ten miles or so before recharging; rarely do I travel more than 15 miles before a charge.

In my case, 4.5 miles is about 20% DOD, with an expected life of more than 2,000 cycles. I've probably done about 1,200 cycles in 4.5 years. I use US8VGC batteries, and they have a similar cycle life curve. The pack seems to have 'hit the wall' about six months ago - I noticed reduced acceleration and range about then.

In case everyone doesn't know what I drive, it is perhaps one of the smaller EVs here, but is similar in the complexity of challenges presented. The Citicar was actually a 'factory' car from back in 1976 - I have done a number of changes to make it somewhat more reliable:
http://evalbum.com/1196

Tom Keenan

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## EVDL List (Jul 27, 2007)

*Re: [EVDL] Golf cart battery capacity (Energizer GC8)*

Hello Tom,

The last battery pack which was a Trojan T-145 6 volt battery lasted 8.7 
years where 6 out of the 30 batteries was down to about 50% of capacity. 
Had over 3200 cycles which includes at least 1 cycle a day and sometimes 2 
cycles a day. 24 of these batteries are still running in another EV.

Drove every single day on a short run which was a 1.1 mile up hill that use 
3.5 to 4.0 AH out of a 245 AH battery. Had at least two long 5 mile a week 
run. Charge every time with a PFC-50B at 50 amps. The charge time was about 
5 minutes. It charge very quickly to the acceptance maximum voltage which 
was just over a minute it took longer for the current to drop to 5 amps.

Charging in this short amount of time, the batteries did not heat up as much 
when I was during much longer charges with other battery packs that I drove 
10 miles a day which I charge at 30 amps.

The battery pack I am using now, is a pack of 30 U.S. Battery 6 volt 252 AH 
which I install on Sept 4 2009. This time according to U.S. Battery I am 
charging them at 25 amps to a acceptance voltage of 7.75 volts per 6 volt 
battery. Driving the same course every single day since they are install, I 
now have 939 cycles in 848 days. The battery temperature after each charge 
cycle only raises the battery temperature from 65 F to about 66.8 F.

I do not charge until the E-meter indicates 100% SOC, but to 98-99% SOC. 
The Link-10 Meter will not accept the 252 AH hour, so I have to set it at 
260 AH which 3.1% over the 252 AH.

According to U.S. Battery, if you have a longer charging time, and the 
battery temperature is 10F degrees below the 80F, it is best not to add the 
0.028 volts per cell for only a 70 degree battery, because if your charging 
time is long, it may increase the battery temperature to 80F during 
charging. I tested this out on a 70 degree day which the batteries was also 
at 70 degrees driving only 5 miles which raise the battery temperature to 
about 80F.

So keeping the battery cooler and shorter charge times, has increase the 
life of the batteries.

Roland






----- Original Message ----- 
From: "Tom Keenan" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Wednesday, December 07, 2011 8:37 AM
Subject: Re: [EVDL] Golf cart battery capacity (Energizer GC8)


> Aside from cycle life, I wonder if any manufacturers put out 'calendar 
> life' expectation of their batteries. If one were able to drive 60,000 Km 
> (6,000 cycles), it would take some 3,000 trips (10km there, charge, 10km 
> back) which would take about ten years to do.
>
> Would a lead acid battery really last ten years, and still have 80% DOD? 
> Or would the plates have disintegrated by then?
>
> I take reasonably good care of my pack, but it is at about 65% after 4.5 
> years, traveling in about the same pattern (4.5 miles to work, charge, 4.5 
> miles back home). Occasionally I travel ten miles or so before 
> recharging; rarely do I travel more than 15 miles before a charge.
>
> In my case, 4.5 miles is about 20% DOD, with an expected life of more than 
> 2,000 cycles. I've probably done about 1,200 cycles in 4.5 years. I use 
> US8VGC batteries, and they have a similar cycle life curve. The pack 
> seems to have 'hit the wall' about six months ago - I noticed reduced 
> acceleration and range about then.
>
> In case everyone doesn't know what I drive, it is perhaps one of the 
> smaller EVs here, but is similar in the complexity of challenges 
> presented. The Citicar was actually a 'factory' car from back in 1976 - I 
> have done a number of changes to make it somewhat more reliable:
> http://evalbum.com/1196
>
> Tom Keenan
>
> _______________________________________________
> | Moratorium on drag racing discussion is in effect.
> | Please take those discussions elsewhere. Thanks.
> |
> | REPLYING: address your message to [email protected] only.
> | Multiple-address or CCed messages may be rejected.
> | UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> | OTHER HELP: http://evdl.org/help/
> | CONFIGURE: http://lists.sjsu.edu/mailman/listinfo/ev
> 

_______________________________________________
| Moratorium on drag racing discussion is in effect.
| Please take those discussions elsewhere. Thanks.
|
| REPLYING: address your message to [email protected] only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| CONFIGURE: http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

*Re: [EVDL] Golf cart battery capacity (Energizer GC8)*



> On 7 Dec 2011 at 7:37, Tom Keenan wrote:
> 
> > Would a lead acid battery really last ten years, and still have 80% DOD? Or
> > would the plates have disintegrated by then?
> ...


----------



## EVDL List (Jul 27, 2007)

*Re: [EVDL] Golf cart battery capacity (Energizer GC8)*



> EVDL Administrator wrote:
> Tom Keenan wrote:
> >> Would a lead acid battery really last ten years, and still have 80% DOD? Or
> >> would the plates have disintegrated by then?
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] Golf cart battery capacity (Energizer GC8)*



> Hoegberg wrote:
> 
> > Pardon my bad English language and writing, but I guess you can understand
> > most of it.
> ...


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