Thread: 12v dc/dc chargers

Originally Posted by drivesafe

.......................................Then on the very next page they had a TIME based graph where they claimed their DC/DC device will charge two 100Ah batteries from 75% SoC to a fully charged state in 150 minutes where an alternator would take 180 minutes to fully charge the same batteries.

Now the first problem is that the graph only covered charge batteries from an SoC of 75%. This means if someone never took the two 100Ah batteries below 75% then they only ever used 50 amperes of power..............

(EDITED FOR BREVITY)

Aah.............'lies, lies and statistics', or as I think someone pointed out earlier, marketing.

I take your point that the principle is sound, but does this translate into practice ?
From the details given it would appear that for a common set up ( 2 X 100Ah flooded cell batteries ) the singular benefit is if you only discharge your batteries down to >75% SoC AND travel more than two and a half hours BUT less than three hours that there is any benefit.
Seems to be a hell of a narrow set of circumstances to make this device worthwhile.

Originally Posted by drivesafe

.......................................So why the hell then did they have two 100Ah batteries in the first place .....................

(AGAIN EDITED FOR BREVITY)

This one's easy. Redundancy.
I do quite a bit of remote outback travelling and battery failure caused by driving on corrugated roads is a real problem. Never had a battery last more than two years until I swapped to Optimas. Best thing I ever did. Might cost more initially but no more collapsed cells and the fast charge more than compensates for the comparatively low capacity (when compared to a similiar sized flooded cell battery).

Deano

thank you for your reply the reason I asked about the dc/dc chargers is that until a few weeks ago ai had never heard of them and on the surface they seem a solution to a problem that I encountered many years ago in my old 2A which was that the deep cycle battery would not charge unless I removed the earth strap of the start battery (I was using a twin battery set up with isolater) also my freelander2 is using the landrover electrics with the 12n and 12s plugs . The white plug has a constant 12v supply for a caravan and an ignition controled 12v supply as well however the wiring seems a bit light for charging
doug