2022 KISS Dual Battery

[Phoenix666]

I have a few issues with the SOC for LIFePO4 batteries... you con only really tell the top/bottom 10%, relying on the chart shown will get you into trouble.
Check out the off grid garage (and others). If you are not using a shunt to check, you really have no idea.
This isn't really a problem, once it gets low/high, you will know, but if it says 50%, you can't assume that is true.

 

[TeCKis300]

I have a few issues with the SOC for LIFePO4 batteries... you con only really tell the top/bottom 10%, relying on the chart shown will get you into trouble.
Check out the off grid garage (and others). If you are not using a shunt to check, you really have no idea.
This isn't really a problem, once it gets low/high, you will know, but if it says 50%, you can't assume that is true.

I don't disagree and if you need the resolution for more mission critical use, sure. I would get a battery that has built in BT/BMS as that has advantages to packaging and reducing complexity. For likely the same overall cost to an external shunt.

Like I said, I have a shunt based monitor for 400Ah LifePO4 in my Airstream. I find the voltage SOC correlation very high. If the LifePO4 is under 13V, a 100Ah battery still reasonably has 20-30Ah. Which is plenty to react. If it's lower 13V, still have 50Ah. That as much as AGMs had in total before.

Either way is workable depending on need. Just saying shunts are not required for KISS.

 

[Mogwai]

I don't disagree and if you need the resolution for more mission critical use, sure. I would get a battery that has built in BT/BMS as that has advantages to packaging and reducing complexity. For likely the same overall cost to an external shunt.

Like I said, I have a shunt based monitor for 400Ah LifePO4 in my Airstream. I find the voltage SOC correlation very high. If the LifePO4 is under 13V, a 100Ah battery still reasonably has 20-30Ah. Which is plenty to react. If it's lower 13V, still have 50Ah. That as much as AGMs had in total before.

Either way is workable depending on need. Just saying shunts are not required for KISS.

For KISS... just have a bigger battery than you're going to need, forget monitoring haha... seriously though, w/ lithium batteries, aside form expedition/always on the road type builds, if you can get 4 or 5 days "running everything hard" what's the need to monitor? Just figure out a way to top up once every few days and keep going.

Re: shunts, agree w/ Teck if you want to go through the effort to monitor (and charge) optimally use a BMS that can output voltages/charge for each CELL, not the whole package. If you're just reading/charging based on the whole pack, as if it was one lead acid, no bueno.

 

[radman]

View attachment 3115170

It looks like your rear blower is completely blocked. Are you having any airflow issues?

 

[TeCKis300]

It looks like your rear blower is completely blocked. Are you having any airflow issues?

It looks that way. Most of the stock intake is only at the forward half. There's a fingers width standoff and gap all around the battery and facade plate, along with a room to breath underneath and around the drawers. I did want to make sure of that. After my long 3500 mile road trip with 6-aboard, it's working well.

Here's some detail pics.

 

[joltman]

I'm in agreement with others that SOC for a LiFePO4 battery can't reliably be monitored from a voltage readout. Off Grid Garage has proven that. After spending the money on a nice battery, I don't want to ruin it by not having accurate charge numbers. As to the wire gauge to be ran from the main battery to the DCDC charger, that will depend on a couple things. First, the Blue Sea wire gauge chart. Second, the manual for the DCDC Charger. I'm putting in a Victron Orion 30A non-isolated charger. The manual (page 7) states at 5 meters, you need 16mm squared cable (about 6 gauge). The other thing is that the terminal block on the charger won't take any larger gauged wire, so you're pretty much stuck at 6 gauge.

Here you can see my in-progress build.

Yesterday, I was able to complete the wiring to the Lynx distributor from the Orion. I used ferrules and lugs to connect it all together and heat shrink to clean up the ends. Today, I will finish wiring up the fuse block and get the radio power ran to the fuse block.

The Orion will be pulling it's power from a Blue Sea SafetyHub 150 under the hood on the Slee Accessory Tray. It will have the manual recommended 60A fuse. However, I need to find the best path to run my 1/0 positive/negative wires from that location (passenger side) to the main battery. I am hoping others that see this thread can show their preferred wiring path for the main battery hookup.

The nice thing about the Orion charger is that it can run in a couple modes. Charger mode (of which it can charge multiple battery chemistries) and power supply mode. Until I get the battery, I will be using power supply mode.

 

[fajitas21]

As compact as the GZ is, it still takes up space. I have to position it in a way that protects the things plugged into its face, taking up more space.

This is a really big problem that none of the battery-in-a-box are realizing. Recessed plug in panels would be a gamechanger. It's the main reason I built my own so I can create those flexible leads or recessed outlets.....

 

[TeCKis300]

I'm in agreement with others that SOC for a LiFePO4 battery can't reliably be monitored from a voltage readout. Off Grid Garage has proven that. After spending the money on a nice battery, I don't want to ruin it by not having accurate charge numbers. As to the wire gauge to be ran from the main battery to the DCDC charger, that will depend on a couple things. First, the Blue Sea wire gauge chart. Second, the manual for the DCDC Charger. I'm putting in a Victron Orion 30A non-isolated charger. The manual (page 7) states at 5 meters, you need 16mm squared cable (about 6 gauge). The other thing is that the terminal block on the charger won't take any larger gauged wire, so you're pretty much stuck at 6 gauge.

Here you can see my in-progress build.
View attachment 3135841

Yesterday, I was able to complete the wiring to the Lynx distributor from the Orion. I used ferrules and lugs to connect it all together and heat shrink to clean up the ends. Today, I will finish wiring up the fuse block and get the radio power ran to the fuse block.

The Orion will be pulling it's power from a Blue Sea SafetyHub 150 under the hood on the Slee Accessory Tray. It will have the manual recommended 60A fuse. However, I need to find the best path to run my 1/0 positive/negative wires from that location (passenger side) to the main battery. I am hoping others that see this thread can show their preferred wiring path for the main battery hookup.

The nice thing about the Orion charger is that it can run in a couple modes. Charger mode (of which it can charge multiple battery chemistries) and power supply mode. Until I get the battery, I will be using power supply mode.

Looks like you got a great setup going on there.

As they say in engineering, better is the enemy of good enough. There's a balance in there. That's not to say there aren't good reasons to add monitors and other accessories. Though it can get overwhelming and cost prohibitive for some. As this thread is KISS, trying to show that the bare minimum can work. Not just work, but work incredibly well. There's no risk to the battery as all Lithiums have a BMS.

I'm enjoying my system which can practically keep the fridge going 24/7 just driving the car a few times a week. With reserve to spare.

 

[ekolpack]

Thoughts:
- Could you combine the original KISS setup with this one? Original KISS up front w/ dual battery tray, and LiFePo4 in back? Probably overkill for most people.
- Some/most LiFePo4 batteries won't work in the engine bay....extreme conditions. One advantage of the original KISS (for me anyway) is space-savings in the cabin.
- LFP4 is getting cheaper, as you mentioned, but a good dual battery tray, and copper wire is getting more expensive....tipping scales towards this newer implementation...or a hybrid of both.
- With the original KISS, what happens if you hook up a good trickle charger, like a Noco? Will it play nicely with dual batts in parallel?
- My current plan is for original KISS. Instead of a LFP4 in the cabinet, there will be an EcoFlow River Pro in back with an added extension battery (around 100ah total capacity). The EcoFlow provides MPPT for solar charging, inverter, extreme portability (especially when leaving the extension battery behind), ability to charge itself directly from the main battery using a 12v cig plug (no BCDC needed), plenty of USB outputs (+ 100W USB C PD), and ability to connect via a phone to monitor and control some basic stuff (charging speed, power usage, input/output voltage/current, etc).....and of course, this all comes with massive space savings, cost savings, and simplicity....win, win, win

 

[tbisaacs]

Thoughts:
- Could you combine the original KISS setup with this one? Original KISS up front w/ dual battery tray, and LiFePo4 in back? Probably overkill for most people.
- Some/most LiFePo4 batteries won't work in the engine bay....extreme conditions. One advantage of the original KISS (for me anyway) is space-savings in the cabin.
- LFP4 is getting cheaper, as you mentioned, but a good dual battery tray, and copper wire is getting more expensive....tipping scales towards this newer implementation...or a hybrid of both.
- With the original KISS, what happens if you hook up a good trickle charger, like a Noco? Will it play nicely with dual batts in parallel?
- My current plan is for original KISS. Instead of a LFP4 in the cabinet, there will be an EcoFlow River Pro in back with an added extension battery (around 100ah total capacity). The EcoFlow provides MPPT for solar charging, inverter, extreme portability (especially when leaving the extension battery behind), ability to charge itself directly from the main battery using a 12v cig plug (no BCDC needed), plenty of USB outputs (+ 100W USB C PD), and ability to connect via a phone to monitor and control some basic stuff (charging speed, power usage, input/output voltage/current, etc).....and of course, this all comes with massive space savings, cost savings, and simplicity....win, win, win

This is what I am currently running

 

[TeCKis300]

Thoughts:
1. Could you combine the original KISS setup with this one? Original KISS up front w/ dual battery tray, and LiFePo4 in back? Probably overkill for most people.
2. Some/most LiFePo4 batteries won't work in the engine bay....extreme conditions. One advantage of the original KISS (for me anyway) is space-savings in the cabin.
3. LFP4 is getting cheaper, as you mentioned, but a good dual battery tray, and copper wire is getting more expensive....tipping scales towards this newer implementation...or a hybrid of both.
4. With the original KISS, what happens if you hook up a good trickle charger, like a Noco? Will it play nicely with dual batts in parallel?
5. My current plan is for original KISS. Instead of a LFP4 in the cabinet, there will be an EcoFlow River Pro in back with an added extension battery (around 100ah total capacity). The EcoFlow provides MPPT for solar charging, inverter, extreme portability (especially when leaving the extension battery behind), ability to charge itself directly from the main battery using a 12v cig plug (no BCDC needed), plenty of USB outputs (+ 100W USB C PD), and ability to connect via a phone to monitor and control some basic stuff (charging speed, power usage, input/output voltage/current, etc).....and of course, this all comes with massive space savings, cost savings, and simplicity....win, win, win

1. No problemo combining strategies. 2018 KISS is for a single large starter/house battery bank. 2022 KISS creates a separate house battery bank. They can co-exist fine.
2. Agreed!
3. Yup, choose your poison(s).
4. Yup. The Noco, or any float charger, see's both batteries in parallel as a single battery/bank, so it works great.
5. Def works great and is what I did for 5 years with a Goal Zero 1000. Lots of great things to be said about a portable battery. If there's one criticism, which is why I went with a built in house battery, is that portable batts do take up space. Especially when things are plugged into the face, and having to manage gear around it so as not to damage the plugs and ports. Off-road, things are moving around and banging into each other. If it works for you, I agree it's one of the best solutions!

 

[rlynch356]

I am running the victron BMV-712 smart.. for SOC and other monitoring... after a couple of cycles it will agree wit the Renogy SOC on the batteries BMS (that is via blue tooth only)... I do like having a visible gauge but it is slightly redundant for just Voltage and SOC monitoring.

 

[speakout525]

Hoping someone can recommend a good chassis ground in the rear cargo area preferably on the passenger side. I'm having trouble accessing a good spot, primarily due to existing drawer system and other things that are just in the way.

 

[sdnative]

Hoping someone can recommend a good chassis ground in the rear cargo area preferably on the passenger side. I'm having trouble accessing a good spot, primarily due to existing drawer system and other things that are just in the way.

There is one on the D-pillar, both sides.

Power to cargo area - what guage wire?

forum.ih8mud.com

 

[speakout525]

There is one on the D-pillar, both sides.

Power to cargo area - what guage wire?

forum.ih8mud.com

Awesome. Thanks - and I think I can actually get to that spot w/out having to remove entire sections of the drawer system!

 

[bloc]

I'm currently (get it?!) weighing out my options for this vs an ecoflow delta 2 + Victron 12/24 to charge it. My only electrical need for it will be an Iceco fridge.

Is there a conceivable way to have this all set up without being in the cargo area? If so it's a slam dunk for my needs. It seems like the charger could go under the dash or maybe behind one of the rear interior panels, but finding space for the battery would be a problem. For the record I don't want to ditch the subwoofer.

LiFePo's don't do well under the hood?

 

[daneo]

Running a LiFePo + Charger under-hood is certainly an option. If keeping the system out of the way is a priority and under-hood looks like the best option, I would suggest getting a battery with on-board temperature monitoring like some of those offered by Renogy. There's been quite a delta observed between under-hood air temperatures and temperatures of the actual cells themselves.

Engine Bay Temp Data Logging Thread

There was some discussion in the the 'what have you done this week' thread regarding the temperature impact to Li batteries mounted under the hood. I currently have an X2Power AGM in the Slee bracket. I mounted a little data logger to the engine side battery terminal just to see what was going...

forum.ih8mud.com

tl;dr I've been running LiFePo under-hood for five years and was only able to get it into shutdown mode with 8+ hours in low range in 90+ degree heat. The battery continues to operate fine once it cooled down. There are a lot of variables at play, but at least with temperature monitoring in the battery you can keep an eye on your specific situation.

 

[bloc]

Running a LiFePo + Charger under-hood is certainly an option. If keeping the system out of the way is a priority and under-hood looks like the best option, I would suggest getting a battery with on-board temperature monitoring like some of those offered by Renogy. There's been quite a delta observed between under-hood air temperatures and temperatures of the actual cells themselves.

Engine Bay Temp Data Logging Thread

There was some discussion in the the 'what have you done this week' thread regarding the temperature impact to Li batteries mounted under the hood. I currently have an X2Power AGM in the Slee bracket. I mounted a little data logger to the engine side battery terminal just to see what was going...

forum.ih8mud.com

tl;dr I've been running LiFePo under-hood for five years and was only able to get it into shutdown mode with 8+ hours in low range in 90+ degree heat. The battery continues to operate fine once it cooled down. There are a lot of variables at play, but at least with temperature monitoring in the battery you can keep an eye on your specific situation.

That’s great info, and thanks for the renogy suggestion.

Where is your charger located?

 

[daneo]

I have an “L” style mount for a BCDC1225 like this, except my mount has the BCDC on the longitudinal side. So my BCDC is between the starter battery and the radiator.

Toyota RedArc BCDC Mount

Need a SOLID mount for your Redarc BCDC unit? Look no further. The all-aluminum, American-made Blaze Off-Road BCDC Mounting kit offers a solid mount for your unit. Heavy-duty, corrosion-resistant aluminum construction Easy install, simply lift your factory battery, slide our mount in, tighten...

blazeoffroad.com

Redarc recommends the BCDC be mounted close to the aux battery, but I’ve had no issues with a 2m route vs the <1m route they specify. As the battery gets closer to fully charged, the current will reduce and voltage drop will be lessened.

I don’t see a reason that bracket and charger couldn’t be used at the Aux battery… mine just ended up by the starter battery.

Sorry for the verbose answer but this is the 200 section after all.

 

[bloc]

Thanks again @daneo that helps.