KISS Dual Battery Upgrade (1 Viewer)

[Julian73]

Unless I can find something more interesting, I’m thinking of going with the Renogy DC-DC with MPPT (DCC50S 50a or DCC30S 30a) chargers. These allow simultaneous DC and solar charging, as well as can be configured to trickle charge the DC feed (starter battery in this case) when not charging. I believe it can sense when alternator is running (even with “smart” alternator) to only charge the house battery while active and to trickle charge starter from solar when not active.

The 30amp is all I need but is only slightly cheaper than the 50amp. I’d need to do some research to see if the max charge rate is configurable. My battery says it’s max charge rate is .5c (50amp) so it would be okay either way. But for longer battery life a 20-30amp charge rate would be ideal.

A charger like this is a bit pricey, but its also pretty much covers all the features that the battery monitors mentioned above cover (especially all the protections). Assuming it’s reliable it should be a nice setup. This might be a big assumption though as in general the internet isn’t too favorable of Renogy.

Currently the market for all in one mppt/inverter/chargers is booming for home market. I’m surprised this isn’t much similar in the RV market. I guess if you have an RV you can fit one of the large home boxes, but that’s tough to adapt to an overlanding rig.

The ideal overland all in one box would actually be a DC-DC/MPPT/Inverter. I can’t imagine there wouldn’t be some market for it, since what we are asking for is all the makings of a larger Jackery/ecoflow “solar generator” just without the battery, so we can provide our own battery bank. I’d love a 1250-1500w box that did that.

I guess a 1000-1500W inverter and the Renogy charger listed above isnt a bad compromise.

Having purchased Renogy product before, with their sketchy customer service I would be leery of getting a charger from them. I went with a RedArc BDDC1240D along with BCDCMB-001 mount bracket for mounting in front of radiators.

 

[lx200inAR]

What are the dimensions?

I’ll have to get the measuring tape out in the AM. I saw a video on YouTube where someone took the cover off, there was a lot of empty space in there. I’m not above recasing it.

 

[ekolpack]

I was inspired by this thread to take the plunge and do a KISS dual battery setup on my '08 TLC. Here's my plan (see attached). I'd like to do grounds for each device on short wires, direct to chassis. My research has shown this is no better/lower resistance than running a ground wire all the way back to the neg terminal...arguably it's better if good solid grounds are performed. I didn't add all the ground symbols everywhere cause hopefully that's obvious.

All + wires will come directly off the + battery terminal (prolly this one) and immediately hit an inline bus fuse. If/when the LiFePo4 is added in the back with a BCDC in between, there will be inline fuses on short wires coming off both the LiFePo4 + and the KISS dual battery + up front. I may add a few other misc things (Andersen plugs, direct solar charging inputs, brake controller, etc.)

How does this look? Any suggestions? Additions? Corrections? Changes? Always best to get more than one set of eyes on this stuff, especially where lots of angry pixies are involved. Aloha!

 

[ekolpack]

Just curious if anyone has tried fitting a Group 27 in the usual spot where folks tend to install a second battery? I thought about the "matched battery" approach but figured I'd be constrained to two Group 35s?

I started a whole thread about this. Two Group 35's aren't much more capacity than a single group 27....so kinda pointless. And unfortunately there aren't many options between group 35 and 27. A standard lead acid starting battery group 27 is 12 3/4" wide, which won't fit in the passenger side without some pretty hefty modifications. But luckily, most (all?) group 27 DUAL PURPOSE deep cycle marine/starter batteries are only 12" wide, which will barely fit in the passenger compartment with very little modification. I'm about to go perform this on my 200 right now using a couple Deka DP27 batteries from Lowes.

Of course the deep cycle marine/starting dual purpose batteries not only have the advantage of serving as both high capacity deep cycle AND high amperage (when there are two) starting batteries, but they are also smaller, and about as cheap as a typical lead acid starting batt. The DP27's from Lowes were only $139 each. This seems like an ideal option....much better than two G35's, which as stated, aren't much better than a single G27.

 

[GOLIGHTLY]

Does anyone have any advice/photos of where they're going through the firewall on the passenger side for the auxiliary battery?

 

[FrazzledHunter]

Does anyone have any advice/photos of where they're going through the firewall on the passenger side for the auxiliary battery?

I assume you mean tapping of the 2nd/aux battery for power into the passenger compartment?
If so it's easy-peezy.
You probably have to pull the glove box to easily pull the cables although the contortionists among us could probably do it by feel.
I wanted to route the lines "just so" and tie them so that does require a pull of the glove box.

I got 2 6 GA cables through one of the cable nipples to an Anderson SB-50/Cigarrette lighter combo in the passenger lower area. The SB-50 mount is a powerwerx surface mount. The cig lighter is fused behind the trim panel.
It's worked great for us.
We may one day extend the lines to the rear of the LC running inside the base/step area.

 

[FrazzledHunter]

I was inspired by this thread to take the plunge and do a KISS dual battery setup on my '08 TLC. Here's my plan (see attached). I'd like to do grounds for each device on short wires, direct to chassis. My research has shown this is no better/lower resistance than running a ground wire all the way back to the neg terminal...arguably it's better if good solid grounds are performed. I didn't add all the ground symbols everywhere cause hopefully that's obvious.

All + wires will come directly off the + battery terminal (prolly this one) and immediately hit an inline bus fuse. If/when the LiFePo4 is added in the back with a BCDC in between, there will be inline fuses on short wires coming off both the LiFePo4 + and the KISS dual battery + up front. I may add a few other misc things (Andersen plugs, direct solar charging inputs, brake controller, etc.)

How does this look? Any suggestions? Additions? Corrections? Changes? Always best to get more than one set of eyes on this stuff, especially where lots of angry pixies are involved. Aloha!

View attachment 3168441

Well...I assume you have an OEM alternator which is a 150A critter. Subtract 90A to run the truck. How's your alternator going to handle it?

 

[Julian73]

I've run a 2awg power lead along with a few other cables from 8 away and smaller through the same grommet as some by FrazzledHunter. Was able to lead down behind footwell panel without pulling glove box. Hint I use a rope splicing did to create a path through the rubber grommets.

 

[GOLIGHTLY]

I assume you mean tapping of the 2nd/aux battery for power into the passenger compartment?
If so it's easy-peezy.
You probably have to pull the glove box to easily pull the cables although the contortionists among us could probably do it by feel.
I wanted to route the lines "just so" and tie them so that does require a pull of the glove box.

I got 2 6 GA cables through one of the cable nipples to an Anderson SB-50/Cigarrette lighter combo in the passenger lower area. The SB-50 mount is a powerwerx surface mount. The cig lighter is fused behind the trim panel.
It's worked great for us.
We may one day extend the lines to the rear of the LC running inside the base/step area.

View attachment 3536849
View attachment 3536851

View attachment 3536853

You’re the man. Wasn’t averse to drilling but you confirmed for me that I can use that nipple. Thank you!

 

[cmw]

Hint I use a rope splicing did to create a path through the rubber grommets.

Rope splicing -fid- ?

 

[FrazzledHunter]

You’re the man. Wasn’t averse to drilling but you confirmed for me that I can use that nipple. Thank you!

You may find that that rubber grommet is heavily taped from the factory at the center where all the factory stuff passes through. I took all the tape off and found that the grommet is split in the center. I elected to put a zip tie in place in lieu of the tape. It's not 100% waterproof I guess. Maybe I'll goop it all up with silicone some day but I have my eye on that other unused nipple for some other stuff in the future.

 

[GOLIGHTLY]

You may find that that rubber grommet is heavily taped from the factory at the center where all the factory stuff passes through. I took all the tape off and found that the grommet is split in the center. I elected to put a zip tie in place in lieu of the tape. It's not 100% waterproof I guess. Maybe I'll goop it all up with silicone some day but I have my eye on that other unused nipple for some other stuff in the future.

Great intel, thank you. Hoping I can wrap up at the office at a reasonable hour tonight and start in on this. Appreciate your time