Slee 2nd Battery Tray Help (1 Viewer)

[LBeckons]

I went with two Interstate batteries, both AGM. The aux battery is the Interstate MT7-75DT AGM...it's the one that the battery tray was designed around. This was my first electrical project of any kind and the planning was the most challenging part. Once I started the actual build it came together easily and nicely. I've got a few pics that I can message you if it would be helpful.

Pics would be super helpful! With all the responses I'm starting to hone in on what I want to do.

This is my setup and I've had no issues.

Stock battery/tray + Slee second tray and yellow top optima + 100w Renogy + Controller.


Its wired like this:

Alternator to the Stock battery to Blue Sea ACR to the Second battery (Slee tray & Yellow top) to Charge Controller to Renogy 100w Panel.

With several circuit breakers and fuse box in between those of course.

So, this is how I think my set up is working or seems to work, I have a monitor where I can see when the AUX battery is charging.

When the truck is running and the stock battery reaches 12.4 volts ACR opens and starts charging the AUX battery. Vise versa when the truck is not running and the solar panel is charging the auxiliary and it reaches over 12.4 volts the ACR opens and starts charging the main battery. Since I've had this setup both batteries start at 12.9 volts.

This is looking like the best short term plan.

 

[vman07]

Nice work.. checked out the thread you linked to. I love the AHC on my truck, but the reservoir takes up a bunch of space where you mounted your aux battery and I'm having a bit of trouble figuring out just how to wedge another battery in there. Couldn't you have the best of both worlds (automatic connecting of the two batteries with ignition on/isolated when ignition off plus the ability to connect them as desired/necessary w/ ignition off) by connecting the switching terminal of the solenoid to the middle terminal of a SPDT switch, then an ignition-on-only source to terminal 3, and an always-on source to terminal 1, per attached pic. Switch in up position - automatic isolation/combining with ignition on/off. Switch in middle position - isolation no matter what. Switch in down position - batteries combined regardless of ignition state. Only "gotcha" would be having to remember to NOT leave the switch in down position. That was my plan, anyway. Anyone see any issues with this?
View attachment 1852753

I see no issues. My fully manual setup does all this with a single on/off switch. My two batts. can be connected/disconnected regardless of ignition position. I personally don't like the idea of the default being: both batteries automatically connected after ignition is powered. Some of the expensive auto solenoids connect both batteries 5 minutes after car has started, in order to allow the starting battery to recover (from the alternator) the small discharge of starting the car.

I usually link my batteries manually after about 5 minutes of running the car. Or never if its a short trip around town.

 

[kruisinkid]

The auto charging relays typically operate on sensing the voltage of the main battery once the alternator has recharged it to relay’s set voltage point then closes the relay to then link the batteries in parallel to charge the aux battery. I have not yet come across a time based auto charge system

 

[vman07]

I have not yet come across a time based auto charge system

National Luna dual batt. charging kit/setup allows starting battery to charge for 5 minutes before linking to second batt.

https://www.nationalluna.com/wp-content/uploads/2017/09/NL-SP-Charging-Kit-DIY-2018.pdf

 

[kruisinkid]

SHAZAM! I stand corrected. The timer seems unnecessary with the voltage sense already built into it. Those diagrams at the end of the instructions from your link should be very helpful for many folks trying to plan an aux battery system

 

[LBeckons]

Thanks for the replies everyone, gonna do the power steering flush at the same time since it's leaking a bit. I like the idea of the national luna kit. I wonder if it works both ways, say my aux battery is full from solar does it connect the and charge the main automatically?