House batteries

[Keith Moffett]

I replaced the house batteries about 4 years ago with 6 volt 'Trogan' lead acid batteries.  I have no reason to replace them beyond that we are thinking of the Gillette rally and I like to be prepared.
Isnt 4 years about the end of the life cycle?  Why would AGM batteries be better this time considering the added cost?
What monitor might be installed that would improve the power management?
Does anyone actualy 'equalize' the batteries as Zantrex suggests in the manual?  Why?

Thanks
Keith

[Edward Buker]

Trojan Golf Cart batteries have very rugged thick plates designed for many discharges in service. I would not be surprised if you gt 8 years or possibly more out of these batteries provided you use distilled water, never let the liquid level go below the plate level, and maintain charge.

AGM batteries do not offer much of a benefit other than by design they do not consume any liquid so they are more forgiving if you are not inclined to do maintenance. There may also be a benefit with less corrosion by products in the battery area.

 As far as power mangement, just knowing when you are down to about 40% charge level and start a recharging cycle is about all you need to do. The 40% charge level relates to about 12.3 V without a charger running and a light load or no load on the battery at the time of measuring the voltage using the Xantrex panel.

I equalize the battery bank using the Xantrex about once a year. It uses a high charge rate with higher voltage that puts what is known as a "the gassing voltage" on each cell. That process really produces a lot of gas discharge in the solution and that activity will mechanically knock off some of the sulfate coating that will accumulate on the plate faces which inturn provides a little more capacity by having that area of the plate available and working for you again. It is probably worth doing if you are looking for charge capacity for being off the grid. If you do not dry camp then it is optional given that you will not need the extra capacity. Hope this helps.

Later Ed

[Keith Oliver]

I offer my experience only, no real expertise, but I have been boating for over 40 years and have run across this debate consistently the whole time.
Put a voltmeter on the batteries after you are disconnected from shore power for an hour and see what voltage they are putting out.  It should be 13.8, or close to that.  If they "measure up" you are good to go.  I have seen 10 years in normal service, with a "smart" charging system.  
If you have an application where you can not see the tops, so checking the water level is difficult or impossible, if the batteries get laid over on their sides or inverted, or if your usage demands a faster charging rate, then you will need AGM.  Otherwise, you should get the same service from your Trojans for 1/2 the cost.

[Joel Ashley]

If you use Keith's voltage check, and have a solar panel exposed to light, be sure to cover the panel or pull its fuse on the controller or inline, or you may get a misleading reading.

Joel

[Edward Buker]

Keith,

The 13.8V is only with a charger on the battery set, perhaps that is the solar unit charging that you are seeing voltage wise. After the hour of charging being off and the batteries have  settled to charge state voltage, I would think they would be in the 12.6 or 12.7 range. You could check them with a voltmeter when the sun is off the panels, close to getting dark.

later Ed

[Keith Moffett]

Thanks for all the input.  8 years on the batteries is good news.  I will look into equalizing just to keep things tip top.

Keith M.