Battery Charging

[dave17352]

In a earlier post I was talking about what battery I could run my inverter and fridge on. After reading all the replies I am thinking about going with 2 Trojan T105 GC batteries. Which will be just fine in my 5th wheel.
But now I have another question. I will plan on using these batteries in my TC also when I convert over to a 12 volt danfoss fridge. I plan to put them in my old generator bay as that generator has been removed.

When I do this I will not be using a inverter. I plan on replacing the fridge and then running the 8 gauge wire from the Trojan's to the fridge and leaving the same heavy gauge wires that are all ready running to the refrigerator bay from the panel. I also plan to leave the original 12 volt deep cycle in the Lance battery bay. So the question is---Is there a problem with this set up. with the batteries being in different locations. I have a good charger converter in the camper I bought from Randy's best converter. In other words it will all be connected together. I hope this would work for charging all batteries.

I hope you all could understand what I am up to.

Thanks

[Almot]

I "think" if they are all connected together, both for charging and for loads, the Trojans and the single 12V are going to discharge with more-less same rate and 12V will be feeding off Trojans.

If banks are isolated on loads - fridge on Trojans and other loads on 12V - they will discharge at different rate. Then charging these 2 banks will be a pain because they are discharged to different levels, and besides, single 12V and Trojans might have different setpoints.

what happens when I am driving down the road and the batteries are charging. Isn't the same thing happening again between truck and camper batteries

Yes, no good. To make it easier for batteries, you can use gizmo called Trick-L-Charge. It will stop charging one bank sooner than the other. I would rather ditch the 12V and get those biggish Trojans - 240 AH, not 225 AH.

[dave17352]

You all bring up the points I was thinking about. With the 2 105 I am sure I could ditch the one twelve volt in the lance battery bay. Sounds like you all think that is the thing to do. Basically if you were looking from the rear of my camper on the left would be the original battery. In the middle the panel and converter charger on the right the existing fridge which is wired for dc operation from the factory. To the right rear in the generator compartment I will locate the two trojans in the old generator bay. So if they are connected together your saying either the trojans or the single twelve volt are going to discharge at a different rate. Which is not good. Now what happens when I am driving down the road and the batteries are charging. Isn't the same thing happening again between truck and camper batteries and if I had the trojans then I got a whole lot of different batteries charging. 2 in the truck 3 in the camper.

On a 1 to 10 scale 10 being the worst were would you guys rate just tying it all together.

[Almot]

CA is right. It will work but it won't be optimal. I think you have some solar? don't remember.

Charging 2 different battery banks - wet and AGM - with the same solar charger is not a good idea because they have different setpoints. Unless your charger is so basic that doesn't allow adjusting setpoints and simply pumps same Absorb and Float no matter what battery. Though this can be TAD fixed by installing Trik-L-Charge.

Besides, you will be discharging 2 banks differently - one with fridge and another one with everything else. The charger will be either undercharging or overcharging one of the banks.

If you can't/won't make the bank with all same batteries, it's probably better to parallel 2 banks for all loads.

[CA_Traveler]

Are you saying:

Lance battery--------Panel--------Refer area terminals---------Trojans

With the charger somewhere? Perhaps the panel?

[MEXICOWANDERER]

In a pinch I have used the SAME terminal on a cheap stud type circuit breaker to junction wires terminals then branched off the other (fused) breaker stud to power whatever load. A shiny stack of new terminals on one of the breaker's 10-32 studs can safely distribute 40-amps. This is a tip I offer when hinted at.

[CA_Traveler]

It will work but it sounds like you are wiring different battery types in a unbalanced method. This will cause the batteries to charge/discharge differently and effect their life.

Use only the new trojans or the current Lance battery possibly with a switch to select which one. This applies to both charge and discharge.

But then it's not clear to me exactly what you are planning.

Read up on mixing battery types and balanced battery wiring.

[dave17352]

MEXICOWANDERER wrote:
I wasn't aware that RV refrigerators could accommodate a "to from" run of multiple wires including an 8 gauge. Do you have a terminal block handy? This has nothing to do with the feasibility of what you wish to do. In short: It will work fine.

I do not compute what you are saying. I guess I am saying the wires coming from the trojan's will be what ever gauge necessary. Then I will use the existing wires from the fridge bay to the converter. They are heavy gauge. Tying them all together. Perhaps with a terminal block of some type.

[MEXICOWANDERER]

I wasn't aware that RV refrigerators could accommodate a "to from" run of multiple wires including an 8 gauge. Do you have a terminal block handy? This has nothing to do with the feasibility of what you wish to do. In short: It will work fine.