I'm Using 2 deep cycle 6 volt batteries wired in series in my trailer. I bought the batteries last fall after the camping season was over for us. I put the batteries on a 12v trickle charger over the winter to keep them charged. When I initially installed them this year they still were not charged very well. After a couple of trips where I couldn't keep them charged I bought a Schumacher SE-70MA deep cycle charger to charge the batteries. When I reinstalled the batteries in the trailer and switched on the battery it blew two 40 amp and one 15 amp fuses immediately. What gives?

Did you accidentally charge the batteries to reverse polarity? Check to see with a meter.

Most likely connected in reverse. Longshot would be charged in reverse.

Not hard getting the leads REVERSED as the connectors on the battery terminals are the same type.If they were reversed you may have blown two FUSES in the 12VDC Distribution Panel labeled 'REVERSE POLARITY' and then another in-line fuse close to the battery bank.Don't feel bad blowing the fuses as that is why they are in there - to protect from us guys hooking them up in reverse. No Harm DONE... Just blown fuses... You are not the only one that has done this haha...Be sure to correct the wiring before you replace the fuses otherwise they will just blow again...I always look for the word 'NEG' or the symbol '-' Stamped into the outside 6V battery case and make sure this is he battery terminal that goes to FRAME GROUND...The normal trailer wiring colors will be BLACK for positive +12VDC cables and WHITE for negative -12VDC cables. They may white cables and the ones with color stripes will be positive leads... Sometimes however they will be using the AUTOMOTIVE Battery Colors which is RED for positive +12VDC and BLACK for negative -12VDC cables.Roy Ken

In addition to the above you need to get those batteries charged ASAP. A full winter w/o being fully charged means they have lost some life. You could also have a bad cell. How is the water level?Have them load checked to find out their condition.

Hey everyone, thanks for your help. When I read the first reply regarding connecting improperly, it hit me like a lightening bolt that this is probably exactly what I did. I did check the batteries water level and it is fine. I also checked each cell with a hydrometer and everyone looks fully charged. Thanks again for your advice!

6V Deep Cycle Batteries | Good Sam Community

2oldman
Explorer II
Jul 31, 2015
Don't batteries have polarity clearly marked on them?
Dakota98
Explorer
Jul 31, 2015
Triker33 wrote:
Dakota98 wrote:
Your 6-volt GC batteries need an occasional "equalization" charge. The Schumacher SE-70MA charger will not do this.

Maybe I need to equalize mine. I never have and the T-105's only last me a little over 8 1/2 years.

How much longer will they last if equalized?

8 1/2 years is very good.

Here's an article, that I believe is actually by Trojan

Battery Q & A
MEXICOWANDERER
Explorer
Jul 31, 2015
I'm a BRUTE...

Krylon spray paint for PLASTIC

RED +

BLACK -

GREEN for series jumper wire

I splotch a little color on the battery plastic lid too. Pretty hard to screw up connections color coded like this...

I paint the post, a bit of the cable inulatuonñ I
CA_Traveler
Explorer III
Jul 31, 2015
2oldman wrote:
Don't batteries have polarity clearly marked on them?
Yes, but when they can't be seen due to dirt, the cables aren't marked and pictures weren't taken (everyone just know how they came off) then you're up the creek without a paddle. Plus there is no standard color scheme that RV's use. Some may have a plan but none will hold up production because they ran out of some color... :@

Now add to the mix by changing battery sizes, terminal types and locations, parallel to/from serial and we play the battery doesn't work game... :S
CA_Traveler
Explorer III
Jul 31, 2015
One guy changed out his batteries at a CG and then the engine was dead. He was a friend of a friend that I was traveling with. I was told that everything was hooked up correctly and he really didn't want any help. After an hour he started calling for support.

I asked if I could take a look and he said OK just to shut me up - Hey Don what is this cable that is hanging in the back and not connected? :S
MEXICOWANDERER
Explorer
Jul 31, 2015
Ego Ergo

Followed by contents of wallet.

Common affiction. No cure. I remember one Canadian broad marching up to me down here, putting her hands on her hips and yelling..

"EVERYONE knows starter motors do not have brushes! Harrumph!"
wa8yxm
Explorer III
Jul 31, 2015
Again I make my suggestion to paint and over spray onto the batteries.

Way easier than worrying about it. RED for Positive.

On my coach the house batteries I replaced the positive wire so it is RED, big, heavy, and RED, the negative is Factory original black,,, (The factory original on the positive side was black as well but,, well it's a complex hookup.. I'm into Rube Goldburg.. Shore HEAVY cable runs from batteries to generator fuse block.. Factory lead moved to fuse block. On the chassis battery I did something like that too 3 positive wires became one)
CA_Traveler
Explorer III
Jul 31, 2015
Would paint on a battery invalidate the warranty? It would not surprise me...
pnichols
Explorer II
Aug 01, 2015
Mex wrote:
"EVERYONE knows starter motors do not have brushes! Harrumph!"

Perhaps she was thinking of the "starter motors" on certain Onan generators???

i.e. Aren't certain Onan generator models started by applying battery voltage to their generator's output windings - which turns the generator into a motor momentarily for starting of the engine? If so .... this is brilliant engineering .... and maybe a starter motor without brushes?
MEXICOWANDERER
Explorer
Aug 01, 2015
When a Jeep Cherokee was set up on 4-jackstands?

She was wearing one of her half dozen PROUD TO BE POLISH T shirts. I looked at the slogan and quipped "Which one? Mother's or Meguiars?

"See? See? He really doesn't know about cars!"

Amazing. And these people raise children and vote?

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