I just picked up my new flat bed car trailer and have found after going through the trailer that the battery for the break-away switch has no charge. The unit is a Tekonsha brand. I looked at the instruction manul that came in the battery case any found that there were two different kits. One had a in line battery charger and the other did not. The kit that I have does not have the charger. Does anyone know where to purchase the charger. It appears to be a very compact unit that attaches in-line directly to the positive side of the battery.