33 replies to this topic

[pollux]

thank you, rando

[Jack]

Does your truck have a "smart alternator"? If so, you will want a DC-DC Charger. The smart alternators are controlled by the ECU to lower voltages to reduce load on the engine as needed to optimize fuel efficiency. This means that the voltage from the alternator, especially after the voltage drop on the 10 g wires, is often too low to trigger the Sure Power. The DC-DC charger will take whatever voltage the alternator supplies and boost or attenuate it as needed to provide the proper charging profile for your battery

 

I'm with rando on Victron. The 30A DC-DC will set you back about $200. You can get a Renogy 40A for about $195, but you are still limited to 30A charging. I looked into upgrading the wiring on my Fleet front dinette. One look and I decided that I could live with 30A. For us, when we move, we typically drive for at least several hours. 30A for 3 hours is good for at least 80 Ah back into the battery (there are always losses here and there) which is about 40% of our capacity of 220 Ah.

[Zirdu]

Where is the best place to install a DC-DC charger?  Near the motor battery or near the camper battery?  And why?

 

And do you leave in the stock blue sea ACR unit?  

 

If I just add a DC-DC charger will this help with engine charging?  If so, how much?  Or do I really need to change out all the wires to bigger gauge?  

[rando]

The best place is to install next to the camper battery, connected with short wires.  The idea is that the DC-DC charger provides the battery with precise charging voltages, irrespective of what the alternator puts out.  You want to install it close to the battery so there is little to no voltage drop between the charger and battery. 

 

With decent DC-DC charger you do not need the ACR.  The charger senses from the input voltage that the truck is running and starts charging.   One of the biggest drawbacks of a DC-DC charger is that it only charges in one direction, truck -> camper.    If you have solar, you no longer get charging of your starting battery from your camper solar. 

 

A DC-DC charger will only help if you have insufficient charging from your alternator at the moment.  Are you currently not getting much current from your alternator, and do you need charging from your alternator?   With a DC-DC you will get what the charger is rated for, so 30A from the Victron Tr 12-12 30.   Assuming your current wires can handle 35A (10 AWG or larger), then you don't need to upgrade. 

[ntsqd]

In one of the parallel threads roughly on this topic it was just mentioned that at least one particular DC-DC charger is capable of charging in both directions. That was news to me, but not a surprise as I expected that it was coming once the mfg's felt the need.

[pollux]

i got the Battleborn Lithium battery installed in my 2015 FWC Eagle.

Beware that the original compartment for two AGM batteries is not enough for housing two lithiums.

Charging by solar panel to full battery capacity is really fast on lithium.

 

[PaulT]

Two of the Battleborn GC2 batteries fit in the space where my Hawk had 2 AGM Group 24 batteries. They are taller than the Group 24 batteries though. The standard Battleborn is essentially a Group 27 size.

Paul

[JohnCarolA]

I was just reading this discussion and have some questions.  I have a 2016 Hawk with solar, a Zamp solar controller with a LifePo setting and 2 AGM batteries.  I am wanting to switch to a Lithium battery system.

 

It seems, from what I have read here, that you can change over to lithium without issue although there are a few things one can do to optimize the system.  Is this right?

 

My main concern has been about the alternator which I have read can be overtaxed by changing over to Lithium batteries and might fail.  Is this an issue of concern?

 

Thanks in advance. 

[rando]

Nothing has to be changed, you can drop one in and go.  There are somethings you could change to optimize performance but it is not a requirement at all.  

 

The alternator charging issue is almost certainly not an issue, and if anything you will probably find you are want more charging from your alternator due to losses from the wiring.   The easiest way to find out is to try it as everything is now, see how it performs, then make modifications only if they are indicated. 

 

What model truck do you have?

[JohnCarolA]

I have a 2014 Tundra with the smaller, 4.6 liter, V-8 engine.  Quite honestly, I have never noticed that I get anything from the alternator anyway.  I just read about issues with Lithium Batteries causing the alternator to work too hard.

 

Thanks for the reply, by the way!

Edited by JohnCarolA, 02 April 2021 - 02:13 AM.