The Sams Club/Costco GC2 6v golf cart batteries are in wide use now and many have reported years of trouble free use. Many have asked for the proper charging spec's including my self and I've never found them. Until now??Looking at the Johnson Controls web site I found my way to the global brands Varta web site. In here I found Professional Deep Cycle GC2 batteries by Varta which is under Johnson Controls found at the bottom of the page. Here is the manual scroll down to English.When you have two in series for 12 volts like most of us they want them charged at 14.82 bulk and Equalized at 15.6 with float at 13.2.Jeff

That's pretty much the same as the rest of the 6s out there. eghttp://pdf.wholesalesolar.com/battery-folder/charging_instruction_2011_2.pdfThe trick is to find a charger that will do that, when most converters only go to 14.4v. I use a VEC1093DBD which does normal charging to 14.8 and Equalizes at 15.7 all voltages temp compensated based on 77F as nominal

Thanks for posting.I'm planning on using the Mexduocharge, using the Harbor freight charger and a variac. I hope they haven't changed the construction of the charger recently.

BFL13 wrote:That's pretty much the same as the rest of the 6s out there. eghttp://pdf.wholesalesolar.com/battery-folder/charging_instruction_2011_2.pdfThe trick is to find a charger that will do that, when most converters only go to 14.4v. I use a VEC1093DBD which does normal charging to 14.8 and Equalizes at 15.7 all voltages temp compensated based on 77F as nominalThat document states 14.4 bulk, not enough but far better then WFCO's 13.6.

my powermax is floating @ 13.2 Bulk is around 14.8

64thunderbolt wrote:my powermax is floating @ 13.2 Bulk is around 14.8Curious, according to their spec's they only do 14.4.Can you force them into bulk like the progressive dynamics?Jeff

Might have found charging spec's for GC2's | Good Sam Community

Unyalli
Explorer
Feb 15, 2014
BFL13 wrote:
Somebody a couple years ago posted the info on how the newer version went into boost as I posted above wrt 15 min and 14.2 etc.

What is wrt?

LOL ;)

BFL13 wrote:
If you have a PM4, you will go into boost at 65% or any other SOC.

So with the 12v side connected if I throw the converter AC breaker it starts in bulk like a solar controller then backs down?

Jeff
BFL13
Explorer II
Feb 15, 2014
Yes it does boost and then backs down to do the absorption stage at a lower voltage. This is the 'gentle approach" instead of the voltage staying at 14.6 while amps taper until the batteries are charged up. (which is faster and saves generator time)

wrt = with respect/reference to
Unyalli
Explorer
Feb 15, 2014
BFL13 wrote:
Yes it does boost and then backs down to do the absorption stage at a lower voltage.

At 85% soc? 75% soc? If true I'll become a powermax supporter. If I don't have to manually force boost rock on!

BFL13 wrote:
This is the 'gentle approach" instead of the voltage staying at 14.6 while amps taper until the batteries are charged up. (which is faster and saves generator time)

Understood :C

BFL13 wrote:
wrt = with respect/reference to

No need to PC me sir. I'm old school and USAF retired. My skin is not as thin as modern day anti-american's.

Jeff
BoonHauler
Explorer
Feb 15, 2014
Unyalli wrote:
Snip-
When you have two in series for 12 volts like most of us they want them charged at 14.82 bulk and Equalized at 15.6 with float at 13.2.

Jeff

Your absorption and equalize look good but the float is too low. I'd float at 13.8.

The bigger question is how long to float for? Two, three hours?...it all depends on the size of the battery bank.
BFL13
Explorer II
Feb 15, 2014
The SOC you get to when battery reaches the absorption voltage depends on the charging rate. That is the charging amps/battery capacity in AH at the 20 hr rate. Examples for 14.5v on a 220AH bank, using (SOCs approx.)
70a -- 67%, 55a--72%, 35a --80% It is all proportional to that so you can figure it out for any size bank and any charging amps.
BFL13
Explorer II
Feb 15, 2014
BoonHauler wrote:
Unyalli wrote:
Snip-
When you have two in series for 12 volts like most of us they want them charged at 14.82 bulk and Equalized at 15.6 with float at 13.2.

Jeff

Your absorption and equalize look good but the float is too low. I'd float at 13.8.

The bigger question is how long to float for? Two, three hours?...it all depends on the size of the battery bank.

Your definition of "float" is confusing. Float is for weeks and months and the correct voltage depends on temperature. eg, 13.8 is for 50F but 13.2 is for 80F
Unyalli
Explorer
Feb 15, 2014
BoonHauler wrote:
Unyalli wrote:
Snip-
When you have two in series for 12 volts like most of us they want them charged at 14.82 bulk and Equalized at 15.6 with float at 13.2.

Jeff

Your absorption and equalize look good but the float is too low. I'd float at 13.8.

I didn't state absorption as I could not find it in the document. Agreed IMO absorb at 13.8 would be good. Floating at 13.8 will boil them.
Unyalli
Explorer
Feb 15, 2014
BFL13 wrote:
Your definition of "float" is confusing. Float is for weeks and months and the correct voltage depends on temperature. eg, 13.8 is for 50F but 13.2 is for 80F

So now we bring in temp compensation? What converters do this?
Unyalli
Explorer
Feb 15, 2014
By the way, I'm sitting here watching this pounding some Lite's while participating in a few scientific conversations. :B

Ooh Ya !
mena661
Explorer
Feb 15, 2014
Unyalli wrote:

So now we bring in temp compensation? What converters do this?
Only one. Parallax Paramode 4455TC. Boost voltage is low though (14.2V) and reliability is questionable.

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