Dual Battery Setups! Let's see them! Multiple Batteries Thread!

I've read the CTEK doesn't work as well as it should with Solar.

I went with the Renogy DC-DC w/MPPT, mainly to save a few bucks over the Redarc. But I do like the fact that it trickle charges the starting battery with solar when the 2nd battery is full. It's the only one that does that IIRC.

 

Doesn't @Crom have a CTEK system? I think he might be able to weigh in with his experience too

 

Yes. The alternator can/will simultaneously charge the starting battery and the 2nd battery via a DC-DC charger. Depending on the load (headlights, etc.) on the main system, (how much extra energy is available), determines how fast/slow the 2nd battery charges.

 

I do not have CTEK so not speaking specifically. My truck starter battery charges from alternator as normal. I have a DC/DC charger that can quickly charge the secondary/house battery if needed. Otherwise a solar panel will maintain my secondary/house battery. The AGM starter battery may not ever reach 'full'. The secondary/house battery is lithium and I don't try to keep it constantly 'full'. I'd be happy if my starter battery were always near full charge, but it is not.

 

Look at post #250 in my build thread (page 13).

You can see my CTEK setup.

 

as it is, no the battery in the bed, just connected to a solar charger, does not have to be connected to a frame ground.

when I added in a DC/DC charger, the charger placed close to the bed/2nd battery, then had positive and negative large gage cables of equal length running to the starter battery terminals, and the positive is fused at the starter battery. it might be advantageous to also fuse at the 2nd/house battery terminal.
a third complication was adding in a DC/AC converter, and that device requires its' chassis be grounded to the truck frame.

 

I inherited an IBS dual battery system on the truck I just got. For general driving do I keep it in auto linked mode or should it be de-linked unless I need the other battery?

 

I'd be inclined to stay in 'auto-link'
I have a switch that is 'both off', 'auto', 'both on'. I leave in auto, this keeps both batteries 'charging' when engine running. when engine off, disconnected. works best if both batteries of equal size, and age, and both healthy.


BlueSeas. ML-ACR

 

Scott answered your question. Not to get too technical but the alternator can never fully charge your starting battery. The reason is because in order to charge a 12 volt battery to full capacity you need a multi-stage charger, which the alternator is not, it is a constant voltage charger which is different. The beauty of the CTEK is it can take the voltage that's provided from the alternator, plus 20 amps, up convert the voltage to 14.2 or 14.4 volts and completely charge the auxiliary battery. But the magic doesn't end there, if you're parked and you have solar the CTEK will use the solar to charge your auxiliary battery to full capacity properly using multi-stage technology, and when it's full it can and will float charge your starting battery at 13.5V. My Tacoma can be parked and is for months at a time and starting batteries is always float charging cuz the auxiliary battery is full. In other words the C-TEC is a fantastic awesome piece of tech and I wouldn't look any further than that if it suits your needs. I think it included a 5-year warranty at time of purchase. I haven't kept up on anything since I bought mine so check market conditions and read the manual for more info

 

thats what I was looking for. I know the starting battery will never get to full, but had questions about the charge from solar. Didnt know about float charge of the starting battery

 

I have the Battery Tender 2 bank maintainer and it works great, but with the solar I really don't need it. At one time last winter I had the truck and golf cart charging at the same time but rarely am I playing golf and going on a camping trip..lol
Zim

 

That's pretty cool.
I didn't realize they did all that.
I might have to look into these.

 

What he said.

 

Yup

 

That’s a long par 4.

 

I need some help from you guys that know a lot about these dual battery setups.

I am trying to figure everything thing out for me setup, I have the ICECO VL60 Dual Zone Portable Refrigerator, and am wanting to install a second battery for a trip out west this October. This is what I have come up with so far.

Either the, REDARC Dual Input 25A, CTEK D250SE, or Victron Energy Orion-Tr Smart 12/12-Volt 30 amp, can someone that knows the good, bad and ugly about each unit explain the differences?

Thinking about this package from REDARC, I would have to peace everything together from the other to companies.

https://redarcelectronics.com/products/jump-start-dual-battery-kit

I was/am going to install the second battery in the bed, but saw in this thread that someone installed behind the back seat, is this a good idea or not?

Is 4ga wire big enough for a 20 ft run to the back of the truck, or is 6ga big enough?

Going to install this battery. https://www.batteriesplus.com/produ...d-boat/deep-cycle/bci-group-31m/sli31dtmagmdc

In addition, if anyone can point me in the right direction for all the parts I would greatly appreciate it.

 

I just bought a CTEK D250SE. Its $280 on Amazon right now! And I also have that fridge. My battery is a deep cycle group 24, and i will have 2x 100w panels on my roof.

i dont have it setup right now though. I have 1 100w panel, 30a charge controller, and the group 24 battery. I found that that setup is not enough to keep the battery charged on a cloudy day, which is why im adding more

 

@Stranger45 from my limited experience, if your going to run 20ft from starter battery to the rear of the truck, and specifically to a DC/DC charger like the Victron you mention, remember that is really 40 feet of wire. 6 awg is not adequate. I ran approximate 36 feet of 1 awg cable. this is fused at the starter battery positive, and a negative run, and both runs connects to the positive and negative of the Victron Orion TR Smart 12/12 30A inputs. this unit connects with 6awg pigtails into the Victron terminals. the output is a very short 6awg run to a fuse block which then runs thru larger cable to a Lithium battery. The Orion TR Smart when in intermittent use, will completely charge the Lithium battery from say 45% SOC, in about 45 minutes. Lead acid is not this efficient. Normally I get about 42W out of my one 100W solar panel, and this keeps the Lithium battery happy at 55-70% SOC. The Orion TR Smart will pump 425W thru the system initially and tapers off gradually as the Lithium charges. That Orion TR smart is HOT, and your wiring needs to handle that. That cable is carrying way more than 30A at peak charging.This is an overly complex system I set up. I understand their are much simpler systems out there that will do what you want, but I'm of no help there.

 

Thanks for the info.

I won't be adding solar right now.

How long will the fridge run on the group 24?

 

Thanks for the info, I will not be installing solar as of now. The info about the cable is helpful, i was just going off a chart I had seen posted before.