| Author |
Message |
cgoodwin (208.12.29.127)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, June 07, 2004 - 2:15 pm: | |
Many of the solar applications I see use 6vdc golf cart batteries while most of the coach conversions seem to use battery banks composed of 12vdc batteries...Why?
Chris |
CoryDane RTSII (66.155.188.173)
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Votes: 0 (Vote!) | | Posted on Monday, June 07, 2004 - 2:57 pm: | |
Weight will be a big factor
You need two 6v battery in series to make one 12v battery.
Compactness, 6 volt batteries will take up more space, 1/3 to double that of 12v.
Storage, the cart batteries have a bit higher stand, some conversions cannot support the height of the 6v batteries.
I dont have the numbers for amps and such. I think the 6v does offer a better amperage but in the long run the 12v is more convenient.
If you are wiring a 24volt system, you have a lot of jumpers linking all those batteries.
It is best to keep it simple
Charging systems operate the same 6 versus 12 as do inverters EXCEPT a 12v inverter will draw incredible amps. The 24v inverter will also draw a large amount of amps, but whatever the draw, it will be HALF that of the 12v inverter.
It is not so much the battery but what you need, can use, Cost, fit in the compartment, inverter you are using, charging systems and the list goes on.
Unfortunately, it is not a simple formula to get batteries, it all has a bit of give and take to make up the system that you can live with.
"Imagine Your Dreams"
cd |
Henry R. Bergman, Jr. (Henryofcj) (63.224.197.10)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, June 07, 2004 - 4:35 pm: | |
Nothing I can add to the prior excellent post. Sometimes it is just a matter of what is locally available at that time at a good price.
This is what happened with our solar homestead years ago. Trojan T-105's were available locally at a good price soosss we went with them. |
Jim Ashworth (Jimnh) (172.159.5.16)
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Votes: 0 (Vote!) | | Posted on Monday, June 07, 2004 - 5:43 pm: | |
I have found you get the best value from golf car batteries. There are different amphour ratings so be sure to compare apples, etc. Even on the 12v there is great variation.
I have 8 golfcar batteries and they work for me and my tolerance for genset runtime. With the house fridge, tv, micro, etc., I find a couple of hours at breakfast and a couple of hours at dinnertime keeps the batteries up. I am not conservative with the electrons!! Morning coffee is usually off the batteries since it is too early for genset time at most events. TV is on most of the night since my wife doesn't sleep right thru. Figure your usage and genset time and size the batteries accordingly.
Just remember, a huge battery bank will last a long time, but it will take a long time to recharge them. You can run the genset a little at a time every day or continuously for a day every third day.
Jim |
James Maxwell (Jmaxwell) (66.81.214.146)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, June 08, 2004 - 12:37 am: | |
Chris: All of what Cory said should be considered and especially the part on the jumpers to configure 24v from 6v batteries. I think the primary reason for people selecting 6v cart batteries is the claimed amp hour rating, currently 225 from the Trojan T105 (7 yrs ago the same t-105 was rated at 205 by Trojan and the set I had gave me plenty of reason to doubt even that). Nevertheless, 2 of them to get 12v yields 225 and that is superior to anything you can get in 12v, by far. But then, the trade-offs that Cory mentions come into play to get even the 12v. Perhaps Surette has something better in 12v, but I didn't find it in searching their models. I recently went with sealed Dynasty AGM's at 127ah, 12v. Working w/ a 24v system I neted 127 ah @24v; 2 batts.Trojans would have given me 225ah, but that would have taken 4 batteries and almost double the square space. Mine are abt. same height as a t-105, same width, and abt. 2 inches longer, also slightly more than double the weight. |
cgoodwin (208.12.28.149)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, June 08, 2004 - 2:02 am: | |
Very good explanation of battery nomenclature, use, and ratings can be found here http://www.yachtsurvey.com/boat_battery_basics.htm the site is for marine use but is obviously applicable. Someone should store a copy for the readers as this seems to be a common thread here.
chris |
cgoodwin (208.12.28.149)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, June 08, 2004 - 2:28 am: | |
Another good one http://www.marine-electronics.net/techarticle/battery_faq/b_faq.htm |
FAST FRED (4.245.128.171)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, June 08, 2004 - 5:15 am: | |
The 6V units were built for many heavy discharges from the start. The plate material , spacers insulation ect. was all optomized for deep cycle app.
Ususally 2 6V of the same size (in series) will have more usefull amps than 2 12V in parallel.
The reason is there are fewer cell dividers , so more room for lead.
WEIGHT alone is a usefull method or comparing two brands , although the best method is to compare the "20 Hour Rate".
Many marine batts can be had in tall sizes which frequently work well in a coach with a sliding battery tray.
Trojan L16 instead of golf carts.
The best deal is to purchase the battery monitoring equippment BEFORE installing the new House batts.
This will give actual performance , from new , and let you know if your killing then with overdischarging and sub par recharges, or just from sitting.
FAST FRED |
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