Split charge or DC to DC charger

[nickburt]

I've done some research and have started coming to the conclusion I should consider swapping out my TMax split charge in favour of a DC to DC charger.

I currently have the main battery (just for the basic, normal vehicle demand), plus a pair of leisure batteries for all the aux equipment, such as winch, inverter (1200w pure sign wave, used for a whole variety of mains powered kit - fridge, cordless tools chargers etc... etc...) lights, 12v charging and other 12v powered kit etc.. etc.. The long and short of it is that there can be quite a load on the batteries some days, but others, very little.
The aux batteries are charged via the TMax voltage sensing relay, but maybe I should change to a DC to DC charger given the fairly hefty load that can be on the auxiliary batteries and therefore a deeper charge needed for longer.

One of the next projects is to fit solar charging too, to help when not running the engine for a couple days.
While researching DC to DC, I found this, which looks like it would tick all the boxes.

In a similar set up, but on a 24v vehicle, a mate of mine has a single auxiliary battery with relatively low loads on it, no more than a small fridge and the usual phone and tablet chargers, plus other odds and sods.
He was advised to have a DC to DC charger, and has had a Waeco Perfect Power DCDC20 fitted, in what seems to be parallel to a normal split charge (and there's a few issues, that we're going to rip the lot out and start again to resolve). Next couple weeks I'm going to trace everything and draw up a wiring diagram of what he has at the moment, before the rip out to start again.
In short, I'm thinking maybe just use the DC to DC charger during the rebuild.

Thoughts ??? TIA.

 

[nickburt]

Hmmmm...............

 

[Tim]

From my understanding... and I'm thinking of doing something similar... an alternator will only charge your batteries to around 70/80%. This is fine for a the starter battery but not so great, as you say, for your leisure/house batteries. Also a basic VSR split charge system isn't great when you have dissimilar batteries (as you probably would have). The DC to DC unit is like putting your batteries on a smart charger. That said a DC to DC charger is a much more complex and expensive bit of kit and will also need an additional solenoid if you ever want to start the vehicle off the leisure batteries without using jump leads or to join the batteries during winching. If you want to incorporate solar as well then many DC to DC chargers have the built in regulator already. I've been looking at the RedArc brand from Australia and also the CTEK but can't afford it right now.

 

[phxdsrtrat]

I like DC to DC chargers for 2 reasons. You can get a full charge and the charging is "managed" to extend the life of the battery because they tend to be smart chargers. That being said they ain't cheap. I use a Redarc solution myself but they all basically do the same job. Considering the cost of a good AGM house battery I felt it was worth the coin because I tend to stay with the same setup for years and years.

-Curtiss

 

[nickburt]

From my understanding... and I'm thinking of doing something similar... an alternator will only charge your batteries to around 70/80%. This is fine for a the starter battery but not so great, as you say, for your leisure/house batteries. Also a basic VSR split charge system isn't great when you have dissimilar batteries (as you probably would have). The DC to DC unit is like putting your batteries on a smart charger. That said a DC to DC charger is a much more complex and expensive bit of kit and will also need an additional solenoid if you ever want to start the vehicle off the leisure batteries without using jump leads or to join the batteries during winching. If you want to incorporate solar as well then many DC to DC chargers have the built in regulator already. I've been looking at the RedArc brand from Australia and also the CTEK but can't afford it right now.

Exactly where my thoughts are going. Not cheap, but getting it right is more important for the good of the batteries and peace of mind.

 

[nickburt]

I like DC to DC chargers for 2 reasons. You can get a full charge and the charging is "managed" to extend the life of the battery because they tend to be smart chargers. That being said they ain't cheap. I use a Redarc solution myself but they all basically do the same job. Considering the cost of a good AGM house battery I felt it was worth the coin because I tend to stay with the same setup for years and years.

-Curtiss

Exactly, build right, build once. My Tmax VSR has served it's purpose, but I'm not happy with the way the leisure batteries are managed (or not, as the case may be).