2 - 6 Volt Batteries - Newb question

[tonykennard]

Good evening! First time poster, long time reader!

My 2 year old 2018 Funfinder 31BH is equipped with 2 - Interstate 6 Volt Deep Cycle Batteries (GC2-ECL-UTL). I noticed the other day that panel lights showed only the bottom light (basically dead batteries) when checking charge level on them even though they had been used very sparingly. I brought the batteries home, stuck them on the charger (BatteryTender Plus) for a charging cycle (about 1.5 days). when it was fully charged this morning I unhooked and let them sit for the rest of day. When I got home from work, I check resting voltage and Specific Gravity numbers and was shocked to find the following..

Battery F7
6.5 Volts
1 - 1.225
2 - 1.220
3 - 1.225

Battery H7
6.6 Volts
1 - 1.235
2 - 1.225
3 - 1.220

Am I correct in assuming these will require a equalization? I'm at a loss as to why the voltage readings are ok after the charge, but the specific gravity is so low. It was reading right at the line between white (ok) and red (discharged) on my hydrometer from Canadian Tire (not the greatest Hydrometer I don't think)

Any help would be greatly appreciated!!

[Sam_Spade]

allen8106 wrote:
Batteries need to be equalized at least monthly to stay healthy. If your converter can't do that then you need to find an alternative.

Bull. Total myth.

[allen8106]

Batteries need to be equalized at least monthly to stay healthy. If your converter can't do that then you need to find an alternative.

[rrupert]

You may want to upgrade your converter to better handle charging the GC2 batteries. I started a thread on the subject and got some very good information in response:
Boondocker Converters vs. Progressive Dynamics Converters?

[Sam_Spade]

pianotuna wrote:
This url may help:

Good chart but incomplete.
Temperature has a substantial impact on specific gravity.

And voltage and SG usually track pretty closely.
Nominal voltage for a 6 volt battery is 6.3.

So his voltage and SG readings don't "track" with each other.....and one or the other is "off" or the chemistry of the battery means that it won't follow the chart for a "conventional lead acid" one.

[time2roll]

What converter or charger normally charges these batteries?
Probably need to upgrade.

If parked in the sun consider 100 to 400+ watts solar.

[pianotuna]

This url may help:

http://www.batteriesnorthwest.com/batteryschool.cfm?TID=5#ANC5

[Sam_Spade]

I don't see a problem either, at least not one worth worrying about too much.
What exactly makes you think that the SG is low ??
The specific chemistry for that model battery might affect the SG readings some.

I would be more worried about checking your charging equipment.....and your usage routine....to see why they are going flat.

[MEXICOWANDERER]

WOOL clothing is immune to battery acid.

Wear safety glasses

Make yourself comfortable and don't rush things.

I have equalized hundreds of batteries (may well be an understatement)

Some three cell GC batteries have taken in excess of 16 hours to equalize.

11 ELEVEN AMPS constant until voltage reaches 8 volts or 16 in aeries.

[3_tons]

I don’t see an obvious problem, but maybe this will help:

http://support.rollsbattery.com/support/solutions/articles/4347-measuring-specific-gravity

[pianotuna]

Yes, and the batteries may be quite sulphated.