Arrid Twin Charge and AGM's?

Well, when I rang them yesterday they never mentioned different models. You're not talking about their three-stage chargers are you?

Cheers Notso...I'll give them another ring later today (time difference!).

Notso, just rang "All About 12 Volt" in Vic and they confirm taht there are different models. He's lookinh into it for me and will ring back later today with further info. Thanks for the heads-up on the model 'differences' mate.

Cheers

I looked into this issue a few months back for charging the battery in our Ultimate camper. As I understand it Arrid are able to adjust the output voltage to the required charging voltage, hence the need to specify battery type. I then double checked the volatge at the battery when the car is running and it was over 14v. Checking the charge range for the AGM - Fullriver from Alco - and this is fine. So I didn't fit the twincharge. The AGM charges much better than teh Exide Extreme I had earlier.

Peter

Hi Peter, my alt spits out 14.2 volts and the main batt to camper wire run will only be about 3 to 4 metres max, so with the 6-8 AWG cable I intend to use I would expect to see 14 volts at least at the camper end. If I decide to go with an AGM then I dare say that the Arrid I bought a while back will become a redundant item at will therefore be shortly in the Trader section :)

Craig,

That's the conclusion I came to. Plus the AGM never needs to be topped up, it charges fast - by far the best alternative. I got mine through Member - Mainey who arranged for me to collect from Alco. I think they are in all States. Cost me $198 for the 90AH battery.

Good luck

Peter – you say your alternator puts out over 14V
Craig – you say your alternator puts out 14.2V

I take it that you measured those voltages not long after starting a reasonably cool motor. Have you remeasured the alternator voltage after towing for half an hour?

The modern alternator has temperature compensation. The reason for this is that a battery needs a lower voltage to charge it when it is hot – or the corollary to this if you do not drop the voltage of the alternator as things heat up under the bonnet then you will boil the battery dry. The system voltage in my Disco starts at around 14.5V and 20 minutes down the road it has dropped to 13.8V or less – these voltages vary slightly depending on the temperature of the day.

To test the performance of your charging system get any old or new cigar lighter plug, wire it to your multi meter, insert the plug in the cigar lighter socket and observe the meter occasionally whilst you drive. There are several ways you can wire this up – if you have (or can get) plugs the same as the ends of your meter leads make a permanent test lead or just simply attach a couple of wires to the cigar plug you can wind around your meter lead probes.

Some alternators drop to 13.5V when up to running temperature (my first Disco did.) If you have one of these and you do not have any voltage boost then you will be cycling your battery over the range of around 20% - 55% of its maximum capacity. This is inviting sulphation to form – not good for the battery.

I suggest you do these checks before you dispose of your Twin Charge.

My Twin Charge has a 14.5 V output. I have disconnected it as I think it may have contributed to the demise of my low maintenance battery which requires less than that for effective charging. I have not removed from the van as I can simply replace the fuse and give the van battery enough charge for one nights lights without having to run the car's engine.

PeterD

Your right in that my alt spits out a maximum of 14.2volts. This is one of the reasons I went for the Twin Charge, and also to negate running heavy cables to the camper.

After having a bit of a mull over things this morning I am tending towards something like a Delkor 100a/hr jobby and the Twin Charge - the 'maintenance-free' Delkor will fit in the intended space in the camper, would be charged 100% by the Twin Charge, but more importantly not gas to an explosive level (which does worry me).

I'll check the alternator voltages with a meter tonight, both cold donk and after/during a run.

Thanks Jeff. Looking at something like a Delkor DC27 IF I keep the Twin Charge or a FullRiver DC90 if I DUMP the Twin Charge. What I don't want, and the reason for the initial questions, is to have hydrogen build-up in my camper from correctly charging a DC wet and open battery from the Arrid. Max in, max out. Oh and I forgot to mention, the Carry Me Camper is what I have and as it's designed to be removed from the tray-back the battery system must stay with the camper to keep the Engel running and the beers cold :)

Thanks

I can't remeber the exact voltage, but the calcium-calcium batteries to not gas under 15v (I think!).

I have 2 x 105 amp/hr calcium-calcium. One under the bonnet as the main aux and a secondary aux in my MDF storage box in the rear cargo area of the car in a battery box. I leave it on a 14.7v three stage charger whenever it is parked up at home (I have a charge socket in the front grill) as my alternator doesn't put out enough volts to keep them 100% charged.

I havn't blown up yet... So I reckon you'll be right? ;-)

I don't use an arrid twin charge, just a simple arrid smart relay. I charge a wetcell 700cca starter and the two calcium-calcium batteries while the car is running.

Cheers Jeff.

Thanks Grungle. I did that for the Full River DC90 where the data sheet states 14.5~14.9V for the boost stage, then lower volts for the float stage so I reckon the Twin Charge would still be suitable. All I could find on the Delkor DC27 was that it won't gas until above 15volts. PS: the height of whatever battery/s I use is an issue for I want to fit as is the gassing issue.

Regards,

Craig,

it is on the basis of the charging data from the fullriver site that i decided against using the twincharge. i still think you'll find tne regular output from the alternator will be plenty to charge tbe agm while on the road. then use a three stage charger when home.

peter

Cheers Peter. I have been yacking withe a local battery supplier and they have been really helpful, and agree totally with your comments above. Their advice is to stay with a wet battery, but one doesn't gas until the charging voltage is well above 15volts - this will allow the Twin Charge to do its job as designed. Thank you all for you input into this matter. Safe Travels!