Nissan Safari 24v reducer.

Have a friend thats got one with a 12 volt reducer so she can hook her trailer up. However it also runs the stereo and has a seperate switch that she has to turn on to be able to listen to it. Is there any harm in just directly hooking up to one battery or is it easier to run a seperate reducer for the head unit.

If you connect to one battery it will gradually run down. The charging system "reads" the one that's fully charged (the other one) and decides to take a break.

tsl sells them

as above the first batt will go flat put extra load on the second batt and cause problems the alt cannot differentiate the charge levels between the two batteries. you could however put an equaliser accross the two batteries and use relays for trailer plug and stereo the cost would probly work out the same as a stereo reducer 2 circuit and a four circuit trailer reducer

As wall as the charge imbalance current from the alternator is going thru one battery then out to your 12v gear, it's just not a good idea.

Had a 24v Safari, fitted a good quality 8 amp voltage halver and a small fuse box to create a separate 12v system. Worked ok but not great - then realised there was enough room to turn the battery on the drivers side sideways on it's tray and fit a small battery next to it, connected this to the 12v system - this is what made all the difference. Had a stereo with small sub, air comp, trailer plug, security system with central locking.

Voltage halver only ran when the ignition was on and kept my small battery charged, a 24v relay switched most of the 12v leaving just the alarm on all the time. Whole system worked brilliantly.

Driver russ, sounds really interesting. I have the same problem. How did you do it (install the 3rd battery, so it also gets a charge)?