Battery Charging

[ddrueckh]

I purchased two new 6 volt golf cart batteries from Costco. They are Interstate brand GC2-RD. 208 AH. Per the specs, it says that the absorption phase should be 7.65 volts. That would be 15.3 volts for both batteries tied in series. That seems really high. Should I set my solar charge controller to 15.3 for the acceptance charge or leave it at the 14.8 that I have it set at now? Thanks.

 

[Shadow Catcher]

Best practice is usually to follow the manufacturers recommendations. If you have questions call Interstate 866-842-5368 and ask to speak to an engineer.

[skp51443]

It took some looking but I found their spec page:

 

http://www.batteries-faq.com/activekb/questions.php?questionid=1

 

It does look like they are calling for higher than expected voltages:

Bulk Charge Voltage (2.41 VPC)

Absorption Voltage (2.55 VPC)

Absorption Time in Hours

Float Voltage (2.23 VPC)

Equalization Voltage (2.6 VPC)

[Yarome]

Personally.. I would not go over 14.8. Different manufacturers will approach charging with different strategies and goals in mind, however, pretty much across the board 14.8 has been proven to be the best balance between quick charge rates and longevity with the least amount of risk for overcharging and/or excessive off-gassing.

 

In the absorption phase.. voltage "can" be set a little higher.. even though current is actually going to be lower.. which "can" help reduce absorption times, but it also creates more heat. I prefer fast, safe, and longevity over trying to turbo charge the process.

 

JMO. and to each their own, but I don't always subscribe to a manufacturers chosen approach to charging.