camping solar/battery setup.

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Originally Posted by drivesafe

Hi again Scott and I am not sure why you have fitted a DC/DC device.


There are no Land Rovers that needs a DC/DC device to charge an auxiliary battery


All Land Rovers are capable of charging auxiliary batteries, any number of auxiliary/house batteries, faster than an DC/DC set can do.


Fitting a DC/DC device to any Land Rover actually “chokes” the alternators ability to charge batteries.

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Thanks mate. Disimiliar batteries and a built in MPPT and on long trips the ability to charge my big AGM like my smart charger at home ...ie to maximum not just close to max. I understood that lead acid and AGM required slightly different charging profiles and voltages. Added to this, without the dctodc the alternator supplies both as though the 2 batteries were one big battery. I know the alternator will do a good job but i like the idea of maximising AGM battery life and getting a really well charged AGM on long trips.

Cheers

An alternator makes at least 80 amps but a dc to dc is usually limited to maybe 25-35 amps. The cabling between my start and auxiliary is fused to 60 amps. Adding a dc to dc would reduce the charge flowing to the auxiliary.

That's the falacy mick about the alternator argument...even a modestly charged battery will not accept the big amperage that an alternator is capable of putting out. Battery would have to be critically low (Where you are running it so low you are reducing battery life) to accept big amps for more than a few seconds. Besides the RedArc I have can draw 35amps when the battery is low. Believe me the 25amp/35amp DC2DC has nil problems keeping up with a 110ah deep cycle AGM... If you flatten your AGM like you shouldn't and only ever use the vehicle for 10 min drives to the shops then the alternator would be better...

What some people fitting DC2DC don't get is the need to use big cabling to the DC2DC unit. Red Arc has a good guide about that on their web site. I went thicker again.

Cheers

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Originally Posted by ozscott

That's the falacy mick about the alternator argument...even a modestly charged battery will not accept the big amperage that an alternator is capable of putting out. Battery would have to be critically low (Where you are running it so low you are reducing battery life) to accept big amps for more than a few seconds. Besides the RedArc I have can draw 35amps when the battery is low. Believe me the 25amp/35amp DC2DC has nil problems keeping up with a 110ah deep cycle AGM... If you flatten your AGM like you shouldn't and only ever use the vehicle for 10 min drives to the shops then the alternator would be better...

What some people fitting DC2DC don't get is the need to use big cabling to the DC2DC unit. Red Arc has a good guide about that on their web site. I went thicker again.

Cheers

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Yes, I know. I actually have both the alternator and an 80 watt rooftop solar running to the start battery. It is then wired to a Traxide and then to the auxiliary using heavy wire and 60 and fuses. I can't imagine any advantage from adding a dc-dc.

The false argument is that an alternator will only charge a battery to 80%

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Originally Posted by Eevo

The false argument is that an alternator will only charge a battery to 80%

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What percentage does a d2 charge a deep cycle AGM battery to?

Cheers

Well based on the ones in the D2 here and a recent test.. we had full charge in both.....

Silver Calcium and Many recent AGMs charge just fine on the same connection...

But... if people insist on DCDC products at the prices they are then hey....
If I was laying down that coin I'd stretch to a system where the batteries would be LiFePo4.
80ah / less weight and no DCDC unit.

Optima know AGM batteries.

Charging your AGM Battery | Support | OPTIMA(R) Batteries

As they say alternators are not chargers. It is very important if your AGM is run down to take it out and hook up to a charger ....or leave it in the vehicle and have the dc to dc (...charger...) look after it. And per all AGM manufacturers 14.7 volts is the preferred AGM charge voltage . A D2 alt doesn't charge at that. I think the point is an alternator will do fine and keep the battery full however if you want max life and max amp hours in the tank of an AGM then Dctodc has a place.

Also I was lucky as I needed a good auto isolator and I have a contact where I could get the red arc dc to dc at cost so for me it was a no brainer.

The new model of mine does LIPO also.

Cheers

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Originally Posted by Tombie

Well based on the ones in the D2 here and a recent test.. we had full charge in both.....

Silver Calcium and Many recent AGMs charge just fine on the same connection...

But... if people insist on DCDC products at the prices they are then hey....
If I was laying down that coin I'd stretch to a system where the batteries would be LiFePo4.
80ah / less weight and no DCDC unit.

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i like lipo's but how do you do cell balancing?

I have had my optimas down to 6.5volts, and they have bounced back fine just from my alternator which only puts out 13.7volts! Have had these batteries for close to 5 years now.