3 stage battery chargers

www.durst.com.au

Mine is the 15amp jobbie and i have it permanently mounted on the camper trailer.

Call me nieve but why a charger so big, i have one those 0.9 of an amp battery fighters for the batteries in my setup as i was told that trickle charging deep cycle and calcium batteries was better than using a charger that has big amps.

Mine seem to work great when i'm near 240 and charges all 3 of my batteries fully over night.

Oh this is only a query, i'm not saying mine is the way to go, it works for me it mighten work for others.

Baz.

Are you planning on mounting the charger in the engine bay, cause if you are, I don't know if there are many chargers that will fit the bill. I've seen some smaller ones that are designed to be mounted in an engine bay, but I don't think the CTEK is. I have a 3.6 and 7 amp CTEK, and they were about the only ones I could find that are made to withstand water splashes etc for outdoor use (IP65 standard). It's definately worth going for at least a 3 stage charger though.

Andrew

John

Don't even THINK of permanently charging an AGM battery from anything but a really top grade three-stage battery charger.

AGMs are tolerant of charging voltages and currents generally - but if float charged that charge must be kept to as low as 13.1-13.3 volts (even 13.0 is fine in hot places). Unless left standing for years however it's better to first fully charge them and then store in a cool place. They are fine left like that for 12-24 months.

Float charge them too high - and you'll damage them
Collyn Rivers

John

I don't want to be overly dogmatic about this, but I have had a substantial number of reports of AGM failure where the batteries were mounted underbonnet and used in high temps. But next to no failings otherwise.

The common denominator seems to be the high 'float voltages' in a vehicle set-up.

Further, whilst not all AGM battery makers quote the same specs, many recommend 13.2 or so volts at 25 degrees C, and and as low as 12.9-13-volts at 35-40 degrees C.

Do bear in mind that many AGM makers still advise against charging AGMs and conventional lead acid batteries in parallel anyway - early copies of books also advised against it, but I now feel there is no real problem if the starter battery is protected by a Redarc or similar voltage sensitive relay.

On the whole I would prefer to charge the battery fully and simply let it be - if you are using it again within a few months.

As a matter of interest I have set up my new 4.2 litre TD Nissan Patrol with a couple of solar modules on the roof to drive my 60-litre fridge (from a 100 Ah AGM Lifeline battery) via a Plasmatronic PL20 regulator programmed specifically to suit my perceived requirements.

There is also a via a Redarc relay from the alternator.

The Redarc is that company's new low current consumption unit - and I have connected the solenoid via an on/off switch on the dashboard so that I only connect the AGM to the alternator when required (yet having the starter battery protected by the Redarc against excess float charge).
Collyn Rivers

Mike (Harding)
I certainly would not go against a maker's recommendations. But do note that float voltage is at 25 degrees C and that it's a safe bet there is a lower voltage for higher temps. My main concern would be under-bonnet mounted AGMs where ambients are usually closer to 50 degrees C - and often way over in the tropics.
Collyn Rivers