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

I was referring to the fuse between the battery and the CTEK in that photo. The rest is of no concern to me because it doesn't apply to my setup. And it was before I looked harder at my manual.

i have an older version of this. Still same specs though. I really hate wiring, so id rather pay, and probably can't do all of this stuff with a diy setup anyways, so its worth it.

https://www.4x4spod.com/bantamx_w_hd_universal

8 circuits rated at 30 amps at 12.5 VDC per circuit
• 16-position terminal block (easily attach accessories)
• Integrated low voltage cutoff (LVCO) battery protection w/ optional override
• One ATM mini-style fuse for LVCO protection & reset
• Failsafe self-healing fault protection system (from 1.5 to 30amps)
• Current-sensing MOSFETs controlled by a microprocessor (no fuses & relays)
• 50amp auto-resetting circuit breaker
• Operates on 12VDC or 24VDC
• 8-position input terminal block for controlling outputs
• Protection against: overheating, over-current, shorts, reverse polarity & field collapse

 

The no-load current of the 12V twin is ~28A but under load(29psi) it goes up to 50A and draws 68A at 150 psi. Spods are nice but still have the same 30A limit as Blue Seas or Bussman. Compressors should really be separately fused if using any of those.
Edit- you could still use the Spods controller for on/off but you would only use it to activate a fused, high amp relay instead. That would reduce that high compressor current through the Spods terminals to just the relay activation current.

 

They told me i can run it, so im going with that. Plus I have a tank, so when its full it shuts off. My questions haven't been about a compressor, because I've had that setup for years with no issues. I don't do other wiring, so I have no idea on fuses or gauge size.

 

Just pointing out an apparent discrepancy. There are ways around it.

 

I've read a lot on the forums that says Group 34 is the largest dual battery set up you can fit inside the Tacoma. That is not so. Here is a picture of a pair of Group 31s I installed.

 

Damn! Is that yours? How many AH total is it?

 

206 ah total

 

That would = about 206AH's which really equals about 103 to maybe 130 usable AH's if you follow the recommended discharge rate.

 

Which is why I was determined to go as big as possible.

https://www.northstarbattery.com/product/nsb-agm31

 

haha, I stand corrected

 

In the engine bay or in Tacoma as a whole truck?

 

What is everyone using to monitor their house battery?

I’d like to add some sort of monitor to my system to keep track of how my battery discharges over a weekend of camping.

My set up is a Blue Sea ML-ACR with a flooded deep cycle 115AH battery as the house battery. 30A PWM solar controller w/ a 50W panel (it’s getting upgraded to a 200W panel soon).

All my accessories are connected to the house battery.

Ive been running a Chinese diesel heater off the house battery for cold weather camping and I’d really like to be able to keep batter track of how much battery the heater actually uses per day.

I’ve been eyeballing this guy -

$80 Renogy 500A Battery Monitor with Shunt, High and Low Voltage Programmable Alarm, Range 10V-120V up to 500A, 20ft Shielded Cable, Compatible 12V Lithium Sealed, Gel, Flooded Batteries,Black

https://www.amazon.com/gp/aw/d/B07RP5B5P7?ie=UTF8

 

I use the Renogy BT2 in conjunction with my Renogy Charge controller to monitor both my batteries. It connects straight to the Renogy app on my phone and works great. That being said, the Renogy monitor you have listed would probably work great too.

 

I actually just ordered the BT-1 to go with my controller to monitor the solar side of everything.

 

This is what im looking at putting in the truck, a telecom/ups battery.

Do you know of any issues using this as a backup for starting the engine?

 

Should work just fine as a backup to start the engine.

 

I’ve been using that monitor in an aux. battery setup for a separate build and do like that it matches the Renogy family of products installed.

However, I’m having a hard time confirming what the SOC for the house batteries are. It doesn’t appear that the alternator is putting in any positive charge, past the point of the volts getting topped off.

As in, I can get the volts to charge back to full (14.4) while the truck runs, but it does not continue to supply power for the remaining amp hour percentages. Being that its a lithium battery bank, I believe the volts can show full until the % reaches practically zero.

Anyways, my review of that monitor is that it reflects well for consumption (-), but I’m not yet sure if its accurate in the added (+) direction for current flow.

Is anyone familiar with how to manually check the SOC for a lithium battery? My understanding is this is not done by a volt meter, but rather by a battery tester...

 

I ended up ordering the 500a Renogy monitor, we’ll see how it works.

 

for lithium batteries you need a monitor for that chemistry or one that can select for it. Different chemistries have different cell voltages so the wrong monitor or setting can give the wrong info. Pay attention to max charge and discharge rates, they are listed like .1C or .2C which is a fraction of total charge Capacity. 100AH capacity and .2C charge /discharge rate would be 20A. Charging or discharging at a higher current reduces capacity because of internal battery resistance.

 

Solar panel folks, when combined with a DCDC charger, do you need to run the negative from the panel to the DCDC, or could you run it directly to the battery? They all get tied together anyway, my panel connection will be near the hood and DCDC in the back, so I could save a negative run to the back if not necessary and just run the positive to the DCDC.