Regulators Common Positive/Negative

[marcodelhierro]

Hi everyone,

i have this doubt ever since i started to be interested in solar energy.
i live in spain and the great majority of solar charge regulators on the market here have common positive.
i live in a motorhome and installed a solar system. used a Steca regulator but it would not work properly (kind of freezes) when both battery and load are connected to vehicle mass. was looking for a while for a negative ground regulator and bought a Xantrex C35 which would be alright but to my surprise it has no LVD function in PV charge control mode .
anyway, can anyone explain me why the regulators are made with common positive when virtually all vehicles are made with chassis negative? wheres the sense in that?

Thanks

[russ]

Hi Marco - Welcome to Solar Panel Talk!

Let us see what advice the guys can come up with!

Russ

[Sunking]

Here in the USA most have a negative ground. Problem is the battery should not be referenced to chassis on any inverter or charge controller. The designer needs the option to bond either the positive or negative polarity, or even better to float the system with no ground reference.

[marcos]

i tried to disconnect the built in circuits (lights, fans, fridge etc.) from the chassis and run the whole system across the regulator only but eventually had to give up as it was a nightmare to trace down all the connections to the chassis on an old winnebago motorhome. had to leave it like it was.
my next step will probably be buying a morningstar PS30M regulator which seems to have all what i expect from a decent regulator (the functions and reliability of steca, a display showing voltage and both incoming and outgoing amps, plus negative ground). the price here is around 180€.
what do you think about morningstar?
is there something similar on the market equally good but cheaper?
thanks