Low water level in solar charging batteries

[jmarmor]

Hi,
I installed a 600w solar panel charging system to my 4X 6volt Trojan cabin batteries. I'm using a Morningstar 45 controller. I have the PWM set to 14.8 volts on the DIP switches (#4,5,6 on, off, on). I first installed the system last spring and topped off the water level using distilled water. I just went to check on the water level and all the cells were low. It took 2/3 of a gallon of distilled to bring the water level back to covering the wafers (if that's what there are called in the batteries). I have it set for equalization once a month.

Is this a normal rate of water loss?

The batteries have not been used in about two months, although the solar is still juicing them at all times.

Please advise if this is excessive loss of water and whether I should change the DIP switches to a different level, and to what voltage.

Thanks

[96 Wideglide]

Think it's your equalization once a month .
Batteries rarely, if ever, need equalization. Recall reading somewhere, the caps should even be removed from batteries while being equalized.
Sure it is'nt a desulfication cycle you have set up monthly?

[jmarmor]

Morningstar calls it equalization but I thought it is the process of raising the voltage to the batteries to desulfur the plates.

[az bound]

Equalizing shoud not be necessary on a monthly basis. That is probably the cause of the excessive water loss.
Equlization is required when the specific gravity (SPG) of the cells varies from the highest to the lowest by +/- 0.015 (1.245 - 1.260 at full charge).
www.rvtechlibrary.com/battery/bat_equal.htm
www.thesolar.biz/battery_charging_article.htm

[clyon51]

I'm not sure how your controller is setup, but you are surely boiling the batteries. Boost mode should be about 14.6v for Trojans. After 90% charged, it should drop to 13.6v. Float should remain at 13.2v after they are fully charged. Desulf mode is not necessary when they remain fully charged. Desulf should be 14.6 and only run maybe 30 mins a month.

I check my 7 year old Trojans twice a year and add water once. It stays plugged in 24/7/365.

[Shadowcatche]

I chose an AGM because I did not want to have to futz around. Particularly during summer months either install a watering system or check every couple of weeks, the care and feeding of deep cycle batteries is important if you want them to have a long an happy life. Some damage has already occurred with the uncovering of the plates

[vsheetz]

14.8v is correct for the Trogan batteries, Given six months or more since last checking the water usage is probably high but not outrageous. Equalization should not be done monthly - maybe a couple times a year. Checking water level should be done monthly...

I have a very similar setup - Mornignstar, Trogans, etc.

[jmarmor]

Originally Posted by az bound

Equalizing shoud not be necessary on a monthly basis. That is probably the cause of the excessive water loss.
Equlization is required when the specific gravity (SPG) of the cells varies from the highest to the lowest by +/- 0.015 (1.245 - 1.260 at full charge).
www.rvtechlibrary.com/battery/bat_equal.htm
www.thesolar.biz/battery_charging_article.htm

thanks for the article. I'll shut off the automatic equalizing.

[Stan&Jacquie]

Originally Posted by jmarmor

thanks for the article. I'll shut off the automatic equalizing.

Would you please post the result of turning off automatic monthly equalization? I'm sure many of us would be interested to know what difference this made.

[az bound]

The main reason for not equalizing on a monthly basis is that it is not necessary as long as the battery/batteries are not allowed to discharge below 50% state of charge (SOC), and no stratification/sulfation will occur in a fully charged battery.
50% SOC for 6 volt is 6.12 volts, for 12 volt its 12.24 volts
The high voltages used durring equilization can cause gasing off, with the resulting loss of water, exposing the plates, which will cause them to deteriorate.
The difference will be longer battery life.
The two links I posted give good information on when and how.