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

Look at my build. Remember - the 2nd battery and all it's attachments are a completely separate system. The only connection between this system and the main system is a 10 ga. wire from the starting battery (alternator) to the CTEK D250SA. Oh, and the secondary system is also grounded to the frame.

 

I'm not sure if I understand your question.

The starting battery is charged by the alternator - that part of the system does not change. (Except for the addition of a diode to increase the charging voltage - which, unfortunately cannot be done on a 3rd gen.)

The second battery is charged by the CTEK (which can be set to a higher voltage). I believe the CTEK and Redarc are identically operating devices.

 

Which Redarc are you planning to get? The new Redarc Manager30 might actually link, charge, etc, without the ML-ACR. But sounds like you already got the ACR... oops.

 

Gotcha, so I'd still need to top off my starter battery with an external charger periodically, as I have a 3rd gen. Would love to be able to raise the charging voltage to the starter battery without having to spend $600 on a custom aftermarket alt.

Its good to know the CTEK is similar to the Redarc. Didn't know that!

I was looking at the 1225D. I would LOVE the manager30 as it does everything I want it to do, but I'm not wanting to drop that kind of cash on this. It's really really pricey IMO. This thread is great BTW, and I'm learning a lot in the convos, so thanks!

 

Looked at CTEK and what I took away is the 120 or 120s (price seems to be the only thing different between them) will send 120a to charge the service battery while also supplying any non-critical auxiliary loads and the 250SE allows you to add a solar charger to the mix.

 

AFAIK, the Smartpass 120 is not a charger, rather a controller. I was looking at installing a 120 with my DA250S, but could not a real need for the 120.

The main reason I wanted the 120 was to be able to utilize the 2nd battery to jump the main battery. The 120 would send up to 5 charges to the main battery - not the same as tying the 2 batteries together. So I decided I didn't need it for my uses.

 

This is from the owners manual:
-SMARTPASS 120S is a solution for supplying current to charge and manage consumers in a dual battery system consisting of a starter battery and a service battery.
-SMARTPASS 120S separates the batteries in a dual battery system and thereby replaces, for exam-ple, a separation relay, VSR (Voltage Sensitive Relay), diode isolator or a mechanical battery selector.
-SMARTPASS 120S connects the starter and service batteries together in order to charge them both from the alternator.
-SMARTPASS 120S protects the service battery from deep discharge which would damage the battery.
-SMARTPASS 120S supplies consumers from the alternator instead of from the service battery while the service battery is charging, which permits faster charging.
-SMARTPASS 120S can be used on its own or in combination with D250SE. In combination, the D250SE and SMARTPASS 120S can charge at up to 140A

After more reading I think I have the features of the Smartpass 120s and D250SE figured out.

Smartpass 120s:
-120a of charging current for the service battery
-Connects the starter and service batteries for jumping
-Allows you to run non-vital loads off the service battery with an automatic low voltage disconnect
-Trickle charge the starter battery from service battery without the engine running
-Does not boost voltage to range needed for AGM battery life

D250SE:
-20a charging current for the service battery
-Solar charging input w/MPPT
-Boosts voltage to range needed to maintain AGM battery life

 

selling my secondary battery tray

https://www.tacomaworld.com/threads/fs-secondary-battery-tray.660365/

 

I'm fixing to be adding a dual battery to the bed of my Tacoma. I'm planning on using the Redarc BCDC charger but I'm hung up on whether to use the 25A or the 40A version. The battery I'm planning on using is a Renogy 200 Ah AGM so it's on the upper edge of what the 25 is capable of and at the lower edge of the 40's capabilities. I will also be running 320 watts of solar. Any recommendations?

And does anybody have any experience with the renogy battery?

 

More to come as the project moves toward the rear of the rig tomorrow. Tonight, the second battery is in, wired, the CTEK charger is working as intended and I got to make five custom cables. All in all not a bad day of self quarantine. I'll be adding some Blue Sea outlets for the ARB fridge and other general purpose use and then figuring out what I'm going to do with all this power.

 

I would have thought the opposite. Home to get you home.

 

We use similar 200AH batteries at work (different brand). They are absolutely massive! I don't think you would be able to fit it under the hood. They are about 3 times the size of the stock battery. Typically it takes 2 people to move them around. To give you an idea of scale, the 2 battery terminals on one end are the same distance apart as a normal battery.

 

I'm planning on putting it in the bed in some of my camper build so space shouldn't be an issue.

 

Home or house battery for house/living/luxury accessories

 

Oh I missed that... Pro: It will probably never get stolen. Cons: 1. It has the capacity of two 100AH batteries wired in parallel, but is the size of three 100th batteries. 2. They are harder to find in a pinch. 3. Being massive, they take up space you could use for other things.

 

Do you have a suggestion for the Redarc? Should I run the 25A or the 40A? My thought is that bigger would be better just to ensure a proper charge on the house battery.

 

I believe 25 would be plenty. There should be calculators online for this, but to deconstruct what we have at work. We use a 24 volt / 30 amp charger for 4 of these. Ours are wired two batteries in series for 24 volts @ 100AH, and the two 24 volt pods in parallel for 24 volts @ 200 AH.

So... 24 volts at 30 amps is equal to 12 volts at 60 amps and would be enough to run 4 of these at 12 volts. Correct me if I'm wrong, but this works out to 15 amps per battery.

 

I'm with you, I don't quite understand why the winch, a high amperage draw item, would go on the house battery where it won't necessarily get the full amperage of the alternator to recharge it while actually winching. I can't remember too many times when I wasn't feathering the throttle and getting the alternator spinning faster than idle when I'm running the winch. With the CTEK, the house battery is limited to a 20 amp charge so it makes more sense to me to have the winch on the battery that will get the 130 amp charge of the alternator.

 

Yup, plus shorter cable runs which will be good for voltage and heat issues under high load scenarios

This reminds me I never did make my high idle widget I wanted to...

 

Spent part of today adding a pair of Blue Sea 12 volt outlets to the rear of the truck. One will be for my ARB fridge, the other for an extension cord to the tent or whatever else comes up. It seemed having two made sense. I ran power and ground for both from the "house" battery and put them each on 15 amp fused circuits. I've never used this compartment so it's become my de facto power vault in the bed. I use a Painless Performance Trail Rocker system for all of the switched loads and that is one of the two heavy cables on the positive side of the battery. I added the military terminals to have some additional attachment points and now I won't lose them since they're tightly attached to the battery and not lost on my bench.