6 volt batteries linked

lalakai

quick question on the possibility of linking three 6 volt batteries with an end result of 12 volt output??  Linking them for 18 volts is okay but not sure if there's a way to use the three but keep it at 12 volts?  Any input would be appreciated.  Thanks.  (Reason I'm asking is that I have the chance to pick up three Trojan 6 volt AGM's, that are currently set up for 18 volts.  I could probably find a fourth battery of same characteristics and may go that route down the road, but for right now the three is what I'm considering.  Thanks again.)

BB.

What is possible vs what is practical...

With DC to DC converter(s)--It is possible to drop the output from 18 volts to 12 volts to run lights/radio/etc. And some charge controllers, it should be possible to set them to charge your battery bank at 18 volts (technically 21.6 volts).

You would probably spend a fair amount of time and money to make this configuration work for you... Probably better off just running 2x 6 volts as a 12 volt bank and keep third battery as a spare (recharge it every few months).

Or, you can get a 4th battery and make a 12 volt bank (two strings of batteries) or a 24 volt bank. We suggest people do not mix old and new batteries together in one bank (new would be ~1 year old or less). If you do get a 4th battery, probably would not plan on it outlasting the other 3 batteries (you can replace 1 battery at a time as each fails, but you end up with a battery bank that is always on the edge of one battery or another failing--I.e., more or less random failures over a couple of years until all batteries are replaced--But you still have a battery bank with "mixed age" batteries, and the random failures will begin again a few years in the future).

-Bill

lalakai

just what I need to know.  thanks for the help.