Reverse Polarity of Batteries

ppine wrote:
This spring I brought the batteries out of the garage after winter storage and hooked them up to my hybrid trailer. There is a sticker on the front of the trailer indicating the standard red for + and black for - just like a battery charger. Immediately it was obvious something was not right, with massive sparks and the melting of the insulation on the cable between the two batteries.

I looked under the trailer and sure enough the red cable is grounded to the frame. Some of the people that build trailers are ******** or on drugs. Don't assume anything.

Now the charger shuts off and restarts every 10 seconds on shore power. The radio doesn't work. Several lights like the refrigerator don't work. I am thinking about upgrading the charger which is a single stage old Magnetek 6332 and 32 amps. Any thoughts?

PP,

You wrote batteries... Are they each 12V jars?
If so, you probably hooked up the first one backwards. That probably took out the radio and the control broad for the reefer. You may have done less damage that you believe because many things (not knowing anything specific here) have reverse polarity diodes included to that are there just to blow the included supply fuse in the event of reverse voltage.

If you have a good free standing charger, try charging each battery and letting it sit a day and then check the terminal voltage on both. If they do not come up to be the same. Do not replace just one. If you need two, get a pair of 6V golf cart batteries and connect them in series.

The Magnetek is not just old and obsolete, it is also bad for your batteries. It is probably doing the stop-start because it is trying to recover a shorted cell. There are many available now that are much better. Two you can count are are Progressive Dymanics or Iota.

Now, you definitely are the first person ever to hook up a battery backwards. (If you believe that, I have a bridge to sell you. You may be one of the few to do it and not done more damaged than just a radio and a reefer board. - and that may just be fuses.) If you buy the beer, I can tell you stories about same as long as the beer lasts.

So, replace the batteries, get a new converter and enjoy the season.

Matt - I did a lot of boat work before the depression,