Smart Alternator Regulators - Does any one know about these?

Ive been doing a bit of research of late as I'm looking to get a GU (though i might have to settle on a GQ) patrol soon and I want to install dual batteries with an anderson plug setup so a 3rd can be added when required.

Any how... My research leads me to believe that most alternators are like cheap battery chargers and therefore dont really work too well to recharge a battery over about 80-85% because the in built regulators slow down the charge. So there is this massive market of "smart alternator regulators" that allow the charging process to run upto 95-100% charge into the battery (i believe most of them are switch mode opperation).

Does any one know do these work or is it a gimmick?

I would be interested in some info on this too. I have often contemplated creating my own high efficiency regulators etc.

Smart regulators.

to know what is a smart regulator, first we need to know about what is a standard regulator, and what is required to charge a battery.

A standard regulator on an alternator is designed to give out a constant voltage (around 14V) and the battery and electrics determine what current is drawn from the alternator.

To 'smart charge' a lead acid battery, there are generally 3 stages.
1. slowly bring up the current to the battery, so it 'takes' (up to about 2 amps from 'dead').
2. charge at the battery's recommended maximum current/voltage until the current 'drops off'.
3. maintain the voltage at the battery's terminals with low current.

It's my understanding that this process would need to be continuous, i.e. not interrupted, in order for it to be beneficial.

Also, this charging circuit (including the 'smart regulator' and battery) would have to be isolated from the car's electrics (alternator and loads) during the charge cycle.

I agree it's a good idea to properly charge the car's battery, but while it's in normal use, the battery is effectively being trickle charged, as the alternator provides the higher voltage to the loads. The only real reason for the battery is to power the starter, and provide some accessory power while the engine is off.

Thats fine simon - except the dual battery setup is to be used as an auxilary battery for powering a fridge and some lighting and prehaps a radio whilst the vehicle is stopped.

The only thing that would possibly be running whilst the vehicle is on is the fridge but that could be connected to the main battery and the auxilary battery completly isolated to take a complete 100% charge.

The SAR-20 seems to be the most popular / common unit and I already have a redarc dual battery isolator.

yep.. forgot about 2nd battery.. duh!!!

I think the Pihrana unit does the same also - with proper charging of the aux. battery during driving.