Re: [PSUBS-MAILIST] Re: K-350 / AGM batteries

["kocpnt tds.net" <kocpnt@tds.net>]

Hi Frank,

 

I made the descision to go with lead acid a long time ago because I need a lot of them and dollar for dollar they are tough to beat. I used something mentioned on the site earlier and checked into Trojan Batteries. Yesterday I talked to a gentalman from Storage Battery Systems which supplies batteries for many solar and wind power plants and was tole that the upper connecting bar as well as plates are quite a bit heavier in a trojan than other deep cycle batteries. They are tested independantly and claim to run thru about 400 cycles before failing. I have seen scrubbers in industrial facilities with the same set of batteries with more than 7 years of service. Mine will be 6 volt measure 11 5/8 long by 7 inches wide and 16 3/4 tall with 245 minutes at 75 amp draw. I will have two banks of 6 to give me 36 volts and an additional two to give 12 volts for instrumentation, lighting and scrubber power.

 

This gentleman claims indpendant test data shows that this battery will have only about 20% of the outgassing of similar sized deep cycle batteries because of the heavier plates and the fact that some manufacture enrichen the acid mix to get more performance from their batteries thus outgassing more and lessening the life.

 

This person sounded sincere and honest, but we need to remember that he is the salesman. He also mentioned therm-oil which is supposedly an additive to further minimize the outgassing and is used by the military in several installations.

 

I don't know if this helps or adds to the confusion but I will either buy the trojans or Interstate for which I am already a dealer. The Interstate batteries weigh 117# each and I will get the weight on the trojan to see whats what.

 

Best Regards,

 

Jim K

On Sat, Feb 13, 2010 at 11:29 AM, <ShellyDalg@aol.com> wrote:

I have read the different specs on batteries and I know the AGM's are the most recommended.

There are quite a few things to consider for sure.

I have a question about charge cycles.

In applications such as ours, a golf cart seems the closest match in usage, where the system is charged at night and then receives a relatively deep discharge during the day.

From my reading the various battery sites, it seems the lead plate's thickness has  an impact on how many charge/discharge cycles a particular battery will withstand before it goes to hell.

Most golf carts use 6 volt batteries in series, and the plates are thicker than the ones in 12 volt batteries.

Now I realize these are all wet cell batteries.

The thicker plates in a 6 volt battery are apparently able to withstand more deep discharge cycles than the thinner 12 volt plates. The overall size of the batteries is close to the same but the 6 volt with only 3 cells has bigger cells, I assume because the plates are thicker.

I've seen some battery manufacturers claim up to 700 cycles, while others don't have a set number of cycles published.

AGM's have advantages as far a spilling, out gassing, and maybe reduced charge times.

I'm wondering how many cycles can be reasonably expected, provided the batteries aren't abused by discharging them too low during any one dive.

Frank D.