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

What are you using for a charge controller, dc-dc? What make/model?

 

https://www.renogy.com/core-mini-12...e=1&gbraid=0AAAAABpTx-ENTo_6GRg3Z7HnIQcRwGcjq

Not to say Renogy is a good brand or not, but like @turbodb stated, the technology just keeps getting better and better, it’s amazing what manufacturers are coming up with in terms of compact size/weight, cold weather protection for lifepo, solar charging, Bluetooth data, etc. I think that’s the way I’ll go, putting a third battery in the bed of the truck and dcdc charging it off the engine and getting priority charging from 200 watts of panels, keep the ml-acr and two batteries under the hood for the reliability

 

I'm using a Renogy 50a mppt that's wired to my alternator and has solar. I also have a Noco 5ah trickle charger that can charge the AGM and lipo if the truck is parked in the garage.

House battery, solar, and mppt install start here in my build thread https://www.tacomaworld.com/threads...ld-and-ramblings.452204/page-35#post-29833498

 

Not sure what I will do when it comes time to replace my AGMs. I can't imagine going away from the ML-ACR configuration and setup because it works so well and has been so dependable.

 

Very cool build, I’ll have to strap in to go through the whole thing. The part I wondered about was the dcdc charger, sounds like the Renogy you have is a dcdc with mppt charging?

My understanding being you can’t run a lifepo battery off an alternator because the batteries take a charge so fast the current cooks your alternator

Exactly how I feel, plus with the time and thought that went into it, I don’t want to undo something I like.

The Odyssey batteries I have are 50ah, so having 2 makes for the storage capacity of one big one in my mind, just broken up for the insurance factor. If the fridge were on the third lifepo in the bed, there really wouldn’t be much need for the second battery, it’s just running lights, most of which are led.

The YouTube video accompanying that Renogy battery in the link said they ran their fridge off it for I think 13 days down to like 20%? Then looked at charging options- 100 watt panel, 400 watt panel, 400 watt panel and charging from the vehicle with the engine running, then the engine running alone. The numbers were really impressive, only like 2 hours to fully charge a deeply discharged (another advantage of the lifepo batteries, lead acid can only only be discharged to about 50% if I recall correctly) 100ah lifepo battery with the 400 watt panels and the engine running. Then think of the idea that if panels are used the entire time and getting effective sun, you’ll never discharge the battery if just running LEDs and a fridge.

 

Just for a reference point, I have one 100watt panel along with a 115ah battery and my fridge runs constantly even with cloudy weather. If youre in the shade or heavy woods I dont know but my setup has been going for a couple years and i will leave the truck sitting for a couple weeks at a time.

Also, i have had to replace almost all of the original renogy hardware at some point except the battery monitor. Ive replaced it all with victron stuff as it dies, last piece of renogy equipment is the smart battery monitor.

 

Thanks...the build has been an evolution over years. I'm about ready to start collecting parts for my second suspension overhaul and trying to decide if now's the time to go long travel.

Regarding charging a lipo of the alternator, I'm not sure about damage to the alternator but I know the voltage is not correct coming off the alternator to charge lipo batteries (it's not high enough for AGM batteries either and my alternator died about 12 months after installing the diode to charge my AGM setup...possibly just a coincidence). That is why you run the alternator to a dc-dc and charge the lipo from that instead of just using the alternator and an isolator.

 

The problem is there’s no limitation on the current and it has to be kept at or under about .2C or 20A for a 100AH lipo battery. There’s more including how the charger finishes topping it off and maintenance but it’s the charger that controls that stuff as long as the alternator has sufficient output.

 

Yeah, my 100 watt panel has been a game changer, the house battery is topped off every time the sun goes down, before, about the third day always had to break down the rooftop tent and drive around for several hours, which if you’re wheeling/exploring, great, but if you don’t want to and just wanna sit, it sucks.

If I commit to a third battery, it’ll definitely be lifepo and I’ll likely go Redarc dcdc, it has everything I’d want.

Yeah, I’m on my 4th set of coilovers and have everything for a 63 Chevy spring swap, truck is very heavy with a Lone Peak wedge, bumpers, sliders, skids, etc. Everything is a work in progress lol, even want to cut up the bumper I built to change the lines, but then I’m like why? Who’s that for?

In my research this is what I’d gathered, lifepo batteries take a charge so well, they can smoke your alternator.
https://youtu.be/jgoIocPgOug

I’ve got a GM alternator, it does a great job charging my Odyssey batteries, typically 14.8v at startup, both installed in 2016, still going strong. I keep them on a Noco battery maintainer constantly, when disconnected from the charger they’re reading 12.8-12.7, which full charge is 12.84 volts according to Odyssey.

 

It has been a while since, but thought I may post it here also. I am very happy with the setup and would do it the same exactly as posted. Added the NOCO connector in the second thread.
What Have You Done To Your 3rd Gen Today? | Page 14069 | Tacoma World
https://www.tacomaworld.com/threads...3rd-gen-today.399305/page-14498#post-30423307

 

I have a 20a Renogy DC-DC that I was using with a 110ah AGM. I'm moving the battery to inside the cab and want to switch to LifePo, but what happens if the battery BMS shuts charging off? My assumption is the DC-DC won't know any better and will keep trying to charge? Will that cause issues with the DC-DC?

 

This is pretty generalized but it shouldn’t. The BMS includes internal switching that simply blocks additional charging until it’s reset. The charger should include this reset ability in its documentation. If not you’ll need one that has it. Some chargers can recognize different chemistries and choose the correct charge profile along with reset capability, some do not. I would assume the wrong charger as well as incorrect usage could trip the BMS and be unable to reset it.

 

Hoping to ask for some help checking my diagram. This is a foreign language to me and my brain struggles with it. Think I got a good draft but really could use some help. I'm unsure of the fuses and breaker pertaining to needing fuses and the correct amperage for each.

Thank you!

 

Newbie to solar here. I have a dual agm battery setup in my truck with a smart isolator so they both get charged by the alternator. Truck doesn’t get driven anymore and the batteries seem to be at 11.8-12v after sitting for a week or so. I would like to add solar to BOTH the aux and house battery. The aux battery does have a fridge connected to it. Looking at these two kits. I assume I have to have two charge controllers?

They are about the same price. It seems two 100w panels may be overkill for this situation?

 

Here’s my current setup

 

The layout looks right to me. Instead of fuses near the batteries, I went with these circuit brakers.

https://www.bluesea.com/products/7149/187-Series_Circuit_Breaker_-_Surface_Mount_200A

 

Are you not near some sort of shore power for these situations? Seems like a battery tender would solve this and be a lot cheaper to implement.

 

You could use a Lifepo house battery and a DC-DC charger for the house. There are even ones with an input for a solar panel.

 

Agreed, my experience is the panel is great for providing an energy offset if that makes sense- works best in direct sunlight, typically when the fridge is working its hardest, so it’s a trade off.

A battery charger/maintainer is better for providing a constant float on the batteries to keep them consistently topped off and doesn't fluctuate.

 

https://www.redarcelectronics.com/us/battery-chargers/dc-dc

I like Redarc BCDC chargers, completely sealed and weatherproof so can be mounted in the engine bay, the size of a 6” chunk of 2x6, priority charging for solar.

There’s others out there now, but my thinking is Australian companies really tend to push quality/innovation