Community Forums

S2kskibum · 11-11-2012, 11:03 AM

I just acquired four new Trojan 1275 batteries. I already have a bank of two 12V in parallel and two 6v in series for my coach batteries (in addition to the main starting battery) - its the way it came when I acquired the coach. Wondering if simplyfing to all 12 volt batteries in parallel would make sense, or if I can add the four new batteries, wired in parallel, and simply tie the new battery bank into the existing system. My solar keeps my existing batteries charged great - just would like some extra umph, and these were free... How many is too many?! '94 Bounder 34J F53, headed to Mexico for the winter!

Suggestions or thoughts? Thanks!

clyon51 · 11-11-2012, 11:26 AM

My first question would be do you really need 8 batts and need to carry that extra weight and use the space? Are you happy now with what you have?

More is not always better, even though I rarely think that way myself

I'm guessing you have close to 500AH now. Those 4 T1275 will add another 600AH. If it were me, I'd drop the two T105s and go with the 6 T1275s all in parallel.

v8dave · 11-11-2012, 11:53 AM

Quote:

Originally Posted by S2kskibum

I just acquired four new Trojan 1275 batteries. I already have a bank of two 12V in parallel and two 6v in series for my coach batteries (in addition to the main starting battery) - its the way it came when I acquired the coach. Wondering if simplyfing to all 12 volt batteries in parallel would make sense, or if I can add the four new batteries, wired in parallel, and simply tie the new battery bank into the existing system. My solar keeps my existing batteries charged great - just would like some extra umph, and these were free... How many is too many?! '94 Bounder 34J F53, headed to Mexico for the winter!

Suggestions or thoughts? Thanks!

The reason Fleetwood connected the batteries in two strings was so when you made a mistake and left something on that drained the batteries you could still start the motor. It's a form of a safety for you to be able to drive out of an isolated dry camping situation, start the motor to recharge flattened house batteries, or drive out of narrow storage space when you left the house lights on for a month and you can't get into the battery box.

I looked up the Trojan T-1275 batteries--looks like you fell into a great deal. However, they are deep discharge batteries. The kind made to power the living space not as motor starting batteries. I'm not sure how they would hold up as starting batteries.

You can parallel two of these T-1275 batteries to supply the living space. Be careful, you may need to get one more jumper and/or different length jumper(s) to safely parallel the two new Trojans.

Check your battery compartment. If you can fit two more batteries in there you could leave the two engine batteries more or less as is and have four batteries for the living space. That would certainly get you more oomph.

clyon51 · 11-11-2012, 12:42 PM

I think I misunderstood your post. I assumed you knew you have starting batteries for the chassis and separate deep cycle batteries for the coach. So I thought you had two 6v and two 12v deep cycles for the coach. I should have known better.

You do not want to use the T1275s to replace the 2 present starting batteries. These are deep cycle and not designed to put out a lot of amps at once, like starting batteries.

If you have the battery space, remove the two 6v (wired in series) and put 2 to 4 of the T1275s in their place wired in parallel. The two 6's have 225AH together. Two of the new ones would have 300AH, 3 would have 450AH, ect.

S2kskibum · 11-11-2012, 03:46 PM

Thanks for the thoughtful replies. Think I will eliminate the two 12v tied to the 2 six volts, replacing all four with the new trojans. Starting battery will stay the same 12v, and I'll have two extras! Rewiring will only be necessary in the battery tray behind the steps - but I have to check the height first. Never understood why the previous owner combined different battery types - but it all works well... part of me says don't touch it!

clyon51 · 11-11-2012, 04:01 PM

Hmmm.... so a previous owner did combine two 6v and two 12v deep cycles for the house/coach batteries?

Generally speaking, you want all the same type and age of batteries in the same bank. So you will be doing perfect by eliminating the two 6v and two 12v and replacing them with the four T1275s!

I'm jealous

vsheetz · 11-11-2012, 06:13 PM

Maybe the previous owner got a good deal on some batteries too.

S2kskibum · 11-11-2012, 06:28 PM

Quote:

Originally Posted by vsheetz

Maybe the previous owner got a good deal on some batteries too.

I am guessing the sleazy dealer I bought from (Paradise Coaches in Sherman Oregon) slapped the 12s in - his "tech" didn't know about the 6's... I bought unseen on Ebay, but am happy now after a lot of work! She is perfect for what we are doing, and mechanically excellent (I hope!).