KISS Dual Battery Upgrade

[audyssey]

I've already purchased and committed to the GZ1000 as it is working great for me. Here's my experience:

The GZ 60W power supply has an input voltage of ~120VAC@1.5A

• My understanding is the rear AC powerport is 100W maximum
• I have been unable to charge my GZ1000 from this power port as the spec should exceed the 100W limit.
• I am able to run my ARB fridge off the AC powerport.
• It is interesting to me that this works for @tbisaacs.

As for @BigMF's questions:
1. I run my fridge with the AC plugged into the rear powerport and the DC port plugged into the anderson port on the GZ.

• I like this setup because it will auto switch back and forth between:
  • AC when the engine/alternator/inverter is running.
  • GZ DC when the inverter is off.

2. The input ports and output ports on the GZ are separate.

• Specifically on the GZ1000, there are 3 included input ports and all input ports can be stack.
  • On the included internal PWM charge controller.
    • maximum input for the 8mm GZ barrel connector is 120W
    • anderson power port connector 360W
  • If you add the GZ MPPT controller this adds an additional 2 ports and up to 25A.
    • maximum input for the 8mm GZ barrel connector via MPPT is 150W (I'm assuming 15V@10A)
    • anderson power port connect to 375-550W (15-22V @ 25A)-- the manual has been updated since I did my original research here, and the numbers are vague in the spec now. The total input for the controller is 25A and assume I'm using 10A for GZ connector, I think this leaves 22V@15A for the anderson power pole connector (330W). I could be wrong here.
  • Total input power could be (480W + 480W) 960W (or more?)
• The orientation of the anderson power pole connectors are different from the DC input and DC output (if you go that route.)
  • The default 12V should work, but using the anderson power pole, I find, is more secure.

3. I've run my fridge from the GZ 12V DC power while connecting 3 different input sources into the GZ1000:

• house/utility 120VAC into the 60W power supply
• 12VDC@10A from the GZ 12V car charging cable
• 120W from PV solar sources

As the GZ input and output circuits are isolated, there is no issue with charging/discharging simultaneously.

There's a few different products in this market segment. I think the GZ Yeti with the MPPT or Yeti Link is a nice (albeit expensive) option.

But if I had to buy from new all over again, there's new competition in this market space. The Delta EcoFlow 1000 and 1300 are priced and spec'ed to be competitive with the GZ1000 and would definitely be one of the solutions I'd research.

 

[BigMF]

Wow, that is a lot of useful info from both @tbisaacs and @audyssey. Thank you both so much for your time and input.

I was thinking about putting some windmills on top for windpower to charge the power pack but I don't think those are ready just yet.

 

[BAY2MTN]

I would like to avoid the dual battery setup if possible. For multi-week trips (admittedly in the distant future for me), do you think running something like the Goal Zero for the fridge would work long term?

This may belong in the SQOD thread but I'm new to mini-fridges, power packs, solar, etc:

1. Can you use the 115V port in the back to run the fridge while the truck is running during the day and run the fridge at night from the power pack while camping?
2. How do you charge the power pack during the day if it's powering the fridge?
3. Can you run the fridge and charge the power pack at the same time while the truck is running? Is there enough "juice" to do both simultaneously on one battery and stock alternator?

I'm a long way off from any of these things but like to ponder and research far in advance. Additionally, it might also help me while I plan the wiring for my upcoming compressor project.

Hey BigMF,

The other replies are excellent, and above my electrical knowledge. Along with the GZ product, I did see the Dometic PLB40 portable battery might satisfy your needs as well. Plug it into the DC, and the fridge into it. Charges while you drive, runs fridge as well.

Dometic PLB40

Dometic PLB40 - Portable lithium battery, 40 Ah

www.dometic.com

And can take solar input:

 

[RET2]

Hey BigMF,

The other replies are excellent, and above my electrical knowledge. Along with the GZ product, I did see the Dometic PLB40 portable battery might satisfy your needs as well. Plug it into the DC, and the fridge into it. Charges while you drive, runs fridge as well.

Dometic PLB40

Dometic PLB40 - Portable lithium battery, 40 Ah

www.dometic.com

And can take solar input:

Why wouldn't just plugging both into 12v power work better? That way the PLB would be always topped off?

 

[BAY2MTN]

Why wouldn't just plugging both into 12v power work better? That way the PLB would be always topped off?

Not sure I understand what you're suggesting. If the PLB40 is plugged into the rear seat DC, then where's the fridge plugged into? Is there another 12v plug other than the one in the front of the cabin? I think the PLB will be eventually topped off even w/fridge plugged in; perhaps Dometic can answer that.

As I was about to have a 2nd battery setup installed at Mudrak (nonresponsive), so this option is starting to look more attractive given reduced cost (I wouldn't do the install myself), and more portable for other uses.

 

[RET2]

Not sure I understand what you're suggesting. If the PLB40 is plugged into the rear seat DC, then where's the fridge plugged into? Is there another 12v plug other than the one in the front of the cabin? I think the PLB will be eventually topped off even w/fridge plugged in; perhaps Dometic can answer that.

As I was about to have a 2nd battery setup installed at Mudrak (nonresponsive), so this option is starting to look more attractive given reduced cost (I wouldn't do the install myself), and more portable for other uses.

I just assumed that you had run power to the back area, sorry. BTW using the stock 12V receptacle isn't and ideal option. Sorry.

 

[BAY2MTN]

I just assumed that you had run power to the back area, sorry. BTW using the stock 12V receptacle isn't and ideal option. Sorry.

why is it not ideal?

 

[RET2]

why is it not ideal?

In most cases the wiring to the outlet is borderline from a fridge draw standpoint and the cigarette type plug connection tends to vibrate loose when off road. Each fridge draws different amounts of current, some are real misers others are power hogs. There are other variables such as content and filled volume. Not trying to make this sound difficult because it's really not. Search this forum and you will find alot of info, some good, some not. You will just have to find what works in your usage.

 

[BAY2MTN]

In most cases the wiring to the outlet is borderline from a fridge draw standpoint and the cigarette type plug connection tends to vibrate loose when off road. Each fridge draws different amounts of current, some are real misers others are power hogs. There are other variables such as content and filled volume. Not trying to make this sound difficult because it's really not. Search this forum and you will find alot of info, some good, some not. You will just have to find what works in your usage.

Got it.

I think in this scenario, (PLB40 + fridge) the battery is plugged into that lighter plug, and fridge is plugged into the battery, which sounds like it is well regulated (and the actual two-pin connection is sturdy, per video).

I think this is a great entry option for many. I started down the IBS dual battery management path, and started to question the need until I have more electrical demands (multiple aux lights run with engine off, and future winch).

 

[Scylth]

First, thanks @TeCKis300 for the thread. I like the simplicity, and the little bit I know about electricity makes sense. Long term, I'm think I'm going this direction.

Short term, I'm wondering if a battery system similar to PLB40 (vehicle port to PLB40 to 60L fridge) is the better option until I have time to do the dual battery install. So, a few questions:

1) Seems like to properly charge the PLB40 I'd need to run a separate/dedicated power line to the back of my vehicle that could charge the PLB40 appropriately to keep the fridge running. I assume this means matching charging draw to proper wire size, connector, and fuse?

2) I already have a Dobinson drawer system, and if the PLB40 fit into one of the side panels, that would be ideal. But it doesn't. If all I'm wanting to do is run the fridge, other than a battery, what would i need to build something that would mimic a PLB40? Just a charging regulator for the battery (plus wiring mentioned above)?

Thanks in advance.

 

[Scylth]

These are a good option too, and I'm sure some will roll their eyes at Chinese/Alibaba but the reality is, for lithium batteries and solar components China leads the pack. Here's almost 200aH for less than $600. Good for 4000 cycles. Add a BMS (you can get one for $40) and an inverter and you got yourself a pretty nice setup. Double up those batts and add a larger inverter and now you're overlanding .
US $590.32 6%OFF | 4PCS NEW 3.2V 190Ah lifepo4 battery LFP lithium solar 4S 12v200ah cells not 100Ah for pack EV Marine RV Golf EU TAX FREE

758.2€ 19% OFF|Grade Een 4Pcs 2021 Nieuwe 3.2V 200Ah Lifepo4 Batterij Met Qr Code Lfp Lithium Solar 12V 24V 202ah Cellen Niet 280Ah Ev Marine Rv Golf|Vervangende batterijen| - AliExpress

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After a little research and measuring, this set will fit perfectly in the side pocket of my Dobinson drawer set. What else would I need to run a fridge? Here are my thoughts:

1) 8 gauge wiring and fuse from car battery to drawer compartment
2) BMS between wiring and lithium battery
3) Inverter between lithium battery and fridge? If i'm running the fridge on 12 v, it seems like I don't need an inverter, but I need something give steady, clean power to the fridge, and prevent other electrical issues, right?

 

[grinchy]

After a little research and measuring, this set will fit perfectly in the side pocket of my Dobinson drawer set. What else would I need to run a fridge? Here are my thoughts:

1) 8 gauge wiring and fuse from car battery to drawer compartment
2) BMS between wiring and lithium battery
3) Inverter between lithium battery and fridge? If i'm running the fridge on 12 v, it seems like I don't need an inverter, but I need something give steady, clean power to the fridge, and prevent other electrical issues, right?

I suggest you fuse at battery and at service point.

 

[Mogwai]

After a little research and measuring, this set will fit perfectly in the side pocket of my Dobinson drawer set. What else would I need to run a fridge? Here are my thoughts:

1) 8 gauge wiring and fuse from car battery to drawer compartment
2) BMS between wiring and lithium battery
3) Inverter between lithium battery and fridge? If i'm running the fridge on 12 v, it seems like I don't need an inverter, but I need something give steady, clean power to the fridge, and prevent other electrical issues, right?

Nice, good to see someones trying this, I'm right at the point of doing so myself, the little Group 35 AGM I've been running (2) dometic drawer fridges off is shot, less than a year, won't run the fridges for even 12 hrs before the low voltage cutout kicks in on one of them. So onto lithium.

You'll need a "4S" BMS for those batts - it's been a while since I've looked into this, but I'm happy to help put together a parts list. Though... mostly I'd be researching what "Will Prowse" has already done/tried and going w/ a setup that has been proven, and is simple. His YouTube channel you can get lost in for hours, and his "solar" focussed website may give you other ideas as well.

I assume you are planning to connect it to your alternator to charge via car while it's running? If so, you'll prob want/need some sort of solenoid/battery disconnect (like a Blue Sea ACR). That is unless you think you'll have enough power that by say adding a 100 - 150W solar blanket (Lensun ETFE) would be enough, you could forgo connecting to your car's alternator (this is the route I'm going). Do you expect to ever want to add solar? Do you want to be able to plug into "AC" power when available to keep the fridges running (or start them getting cold) from grid or generator power? You can keep it super simple, or crazy future proof where you can sort of take any power in, and serve out various DC/AC out.

1st step, decide on 12V or 24V. Most fridges will run on either, benefit of the latter of course is lower amperage, smaller wires, etc... but you'd have to add a step down to supply 12V (easy and cheap) for basic USB and other 12V applications. If you ever want to add an inverter, having a 24V system will provide some benefits there as well.

Lastly, I'm not sure if something like this will fit in your space but more recently I've been looking at these "all-in-one" units (these things are CHEAP for what you get, and get good overall reviews - source on eBay): All-in-One Solar Power Packages

PPS... start a new thread, so we don't complicate OPs KISS thread more than we already have

 

[Scylth]

Nice, good to see someones trying this, I'm right at the point of doing so myself, the little Group 35 AGM I've been running (2) dometic drawer fridges off is shot, less than a year, won't run the fridges for even 12 hrs before the low voltage cutout kicks in on one of them. So onto lithium.

You'll need a "4S" BMS for those batts - it's been a while since I've looked into this, but I'm happy to help put together a parts list. Though... mostly I'd be researching what "Will Prowse" has already done/tried and going w/ a setup that has been proven, and is simple. His YouTube channel you can get lost in for hours, and his "solar" focussed website may give you other ideas as well.

I assume you are planning to connect it to your alternator to charge via car while it's running? If so, you'll prob want/need some sort of solenoid/battery disconnect (like a Blue Sea ACR). That is unless you think you'll have enough power that by say adding a 100 - 150W solar blanket (Lensun ETFE) would be enough, you could forgo connecting to your car's alternator (this is the route I'm going). Do you expect to ever want to add solar? Do you want to be able to plug into "AC" power when available to keep the fridges running (or start them getting cold) from grid or generator power? You can keep it super simple, or crazy future proof where you can sort of take any power in, and serve out various DC/AC out.

1st step, decide on 12V or 24V. Most fridges will run on either, benefit of the latter of course is lower amperage, smaller wires, etc... but you'd have to add a step down to supply 12V (easy and cheap) for basic USB and other 12V applications. If you ever want to add an inverter, having a 24V system will provide some benefits there as well.

Lastly, I'm not sure if something like this will fit in your space but more recently I've been looking at these "all-in-one" units (these things are CHEAP for what you get, and get good overall reviews - source on eBay): All-in-One Solar Power Packages

PPS... start a new thread, so we don't complicate OPs KISS thread more than we already have

Thanks for the advice, I’ll start a new thread,am going to make a few calls Monday to some parts suppliers before I do.

 

[Bunga]

You folks are wizards! Hats off to audyssey who thinks (for better or worse) just like I do. And then Mogwai on the batteries. I found the stock lead acid (LA) to be super weak, despite its massive size. I learned about Slee here and immediately added as second battery tray. So I have had to jump from the back-up to stock. Just FYI I tried 2 lithium portables and they could not start it!

I found out from several folks here that the AUS HKB electronic bypass (adjustable diode with fuse) was the way to go to maintain charge. They are available to order right now. So, I'm planning on shifting from LA main, deep cycle LA backup and sealed lead acid solar battery (SLA), to SLA for the starting battery with the alternator diode from AUS, the LA deep cycle for backup house, and Battleborn lithiums for the fridge and backup to the whole system with Blue Sea switches. I'll start out with the BB as my solar battery on 300 solar and then see how it goes. Pretty convoluted to say: The fridge stays on house power until camp, then the solar battery runs it until the next driving stage.

I know about all the heat issues with SLA, but the factory battery and charging system barely works for me with no real load. I have a mylar thermal blanket on the SLA already.

Everyone struggles with these same issues, running complex systems with DCC charging and very fancy solar hybrid converters. Just look at the offshore boating blogs, or the serious RV folks.

 

[TeCKis300]

^No disrespect, but I'd recommend you start your own thread. Lots going on there with not much in common with the keep it simple strategy, KISS, of this thread. Which is to avoid many of the pitfalls and work-arounds associated with dual batts.

I'd highly discourage the diode strategy. It's misdirected for many reasons including:

1) Does not correct the charging profile of the alternator regulator that is meant for flooded lead acid
2) Exacerbates the issue with SLAs - mixing excess voltage combined with the excess heat underhood further increases likelihood of it venting and prematurely degrading the life expectancy of the battery. Hot environments actually require reducing voltage as proper temperature compensation
3) You do need some form of a DC-DC charger to support two batteries at two different states of charge or chemistry

Much of what I've learned comes from the RV community and experience. It's only now that there's been enough time with dual batt installs on these boards that people are experience premature SLA/AGM failure, and understand perhaps we've been doing it wrong.

 

[ohsix]

What's the best battery tray setup for going to the KISS setup as outlined in the original post?

My OEM battery is getting weak and due for replacement. I like the idea of running dual, matched, lead-acid batteries.

I see Slee makes a 2nd battery tray for passenger side (description says fits group 35) as well as a replacement tray for the driver side (description says fits group 31) . I also see that TJM makes a 2nd battery tray (description doesn't say what size it fits) for passenger side. What combination of battery trays gets me to matched, lead-acid batteries and what size would those batteries be?

Also, any recommendations on where to purchase the cable and connections for the KISS dual battery setup?

 

[ohsix]

What's the best battery tray setup for going to the KISS setup as outlined in the original post?

My OEM battery is getting weak and due for replacement. I like the idea of running dual, matched, lead-acid batteries.

I see Slee makes a 2nd battery tray for passenger side (description says fits group 35) as well as a replacement tray for the driver side (description says fits group 31) . I also see that TJM makes a 2nd battery tray (description doesn't say what size it fits) for passenger side. What combination of battery trays gets me to matched, lead-acid batteries and what size would those batteries be?

Also, any recommendations on where to purchase the cable and connections for the KISS dual battery setup?

In case anyone else is interested, I'll reply to my own question. The Slee battery trays only fit the batteries they are advertised to fit (group 35 pass side, group 31 driver side) according to them. So, no way to do dual 27s or 31s with the Slee trays. I didn't have any luck tracking down specs for the TJM tray. What little I did find makes me believe they are hard to buy in the US. I found a few stories of ordering from Australia and waiting up to 2 months for delivery.

Based on my research, it looks like a group 31 will fit in the OEM battery tray. My plan is to just replace my OEM battery with a group 31 and revisit the dual battery idea when it comes time to replace again.

 

[TexAZ]

It takes a lot of trimming to get a group 27 to fit on the passenger side. The power steering reservoir has to move, the airbox has to be trimmed. If you want to go with something other than slee, just check summit racing. Look for battery relocation kit. It will have the tray, cables and end lugs.
You can get a hydraulic crimper from harbor freight to crimp the battery lugs onto the cable.

 

[radman]

In case anyone else is interested, I'll reply to my own question. The Slee battery trays only fit the batteries they are advertised to fit (group 35 pass side, group 31 driver side) according to them. So, no way to do dual 27s or 31s with the Slee trays. I didn't have any luck tracking down specs for the TJM tray. What little I did find makes me believe they are hard to buy in the US. I found a few stories of ordering from Australia and waiting up to 2 months for delivery.

Based on my research, it looks like a group 31 will fit in the OEM battery tray. My plan is to just replace my OEM battery with a group 31 and revisit the dual battery idea when it comes time to replace again.

How's the paint coming along on the rear bumper?