2 Battery System with dual charging options

[Noah Miller]

Thinking about 2 battery system for 15 LX570 to essentially run a fridge off of while camping. Off grid camping, charged with solar. On grid camping charged at campsite power (Battery tender or plug into battery charging system used for solar?). The reason I wouldn't use solar on-grid is it's usually forest camping in north GA, so can' be guaranteed sun on campsite.

List of needs for far: Solar Panel, deep cycle battery, 2 battery kit from one of a few places, and refrigerator.

I am unclear on charge controllers for 2 batteries, charging from solar and/or AC on those parts. Anyone do anything like this or can list parts I might need? Any vendors around Atlanta do this kind of work?

 

[PabloVTA]

read this one, and then search the forum for MPPT controllers, lots of great info.

 

[Noah Miller]

read this one, and then search the forum for MPPT controllers, lots of great info.

Wish I hadn't, I read it yesterday which got me started on my thinking....

I guess my question is with a solar setup (Panel, House Starting Battery, Secondary Battery, MPPT, relay to connect/unconnect batteries, Inverter), how can I use 110V AC to charge my system when no Sun exists (will have AC available in this situation)?

Can it be as simple as a battery tender/charger (have optimal 6 for Motorcycle already) plugged into deep cycle battery? Feels that simple, which is making me think I'm wrong.

 

[george_tlc]

Yes, it is simple. Just use a decent charger/maintainer hooked to your battery when near AC.

Solar charger connected to battery and connected to panel when using solar.

I use a manual marine switch to connect both aux and main batteries if I want them both charged (either from solar or from AC). Though for normal camping etc, only the aux needs charging since lights and fridge etc only feed from the aux, so no drain on the main.

cheers,
george.

 

[Cruiserdrew]

X2. What you want to do is easy. I recommend you do it in stages so it isn't too much at once.

Start with your dual battery combiner. I like the BlueSea ACR. It's a bidirectional charging relay that senses charging voltages and automatically combines the batteries. That solves your problem of charging both batteries. That means your alternator is capable of charging both batteries when underway, and your solar can charge your aux, then once it's charged will combine and top your main. Pretty slick. When it isn't charging, like when parked and the fridge is running, it separates both batteries. THere is lots of talk about which one to use-I have found the 7610 to be perfect for normal Land Cruiser use and have 3 installed in 3 different trucks. The one in my FJ60 is 4 years old and has been perfect. And BlueSeas warranty is "as long as you own it", not to mention it is super efficient when closed. Other systems like IBS, NatLuna, and TMax use far more power to keep the relay closed-an important consideration when on solar and you don't have a ton extra to work with!

Any solar charge controller will work. You only need 1. The Morningstar Sunsaver 10 or 20 is excellent, reliable and robust. The 10 is enough for up to 175 watts of panel or so. You want it near the battery if possible, but I have my charge controller inside the cab these days and back charge through the interior fuse panel. Your solar panel can be the folding type or any flat panel mounted on the roof. Folding 100 watt is a good place to start. I have pretty much gone to a roof panel of 160-180 watts. Plenty of power for 2 fridges. If you want to monitor your charging with blue tooth, the Victron 75/15 discussed here is great.

It's worth the effort to have an interior fuse panel. So a largish wire (i used 8 gauge) runs from your aux battery, to your interior fuse panel. Then your interior loads get run from that. So radios, fridge, lighting all run off the interior panel.

To charge from a 120V source you will need a charger-You probably don't need an RV 50 amp charger so something like this would work:
https://www.amazon.com/NOCO-GENM2-W...30888751&sr=8-2&keywords=boat+battery+charger

It will be hard to find a shop to do this, or at least do it well. You might consider doing it yourself so you know how it works.

Make sure all of your main wires are fused at the battery. The MRBFs are great for this.


So your steps:
1-Install #2 battery, with combiner relay and cabling
2-Add interior fuse panel
3-Add Solar charging
4-Add onboard 120v charging if desired.

 

[Noah Miller]

@Cruiserdrew thank you, this clears it up 100%. I read the install manual of the 7610, specifically the wiring diagram looks very straightforward.

Can I bother you for a picture of one of your dual battery setups with the 7610. Specifically the position you mounted it, wire gauge, fuse blocks and grounding. I'm going to scan all the other pictures of other setups as well.

Thanks again.

Noah

 

[Cruiserdrew]

Here is my most basic install. The wires from each battery (+) to the ACR are 2 gauge, fused with 150 amp fuses at the battery. The small visible fused wire you see is a ground. And the tiny green wire is the LED that lights up inside the cab when the relay is closed. This lets you tell at a glance if the system is functioning normally.

The other side of this is the 2 batteries grounded together and each to the engine. I feed the interior panel directly off the #2 battery.

You can make your install fancier with bypass switches and the like but you don't need too.

 

[terrx]

@Cruiserdrew - what fuse type and fuse holders do you use at the battery?

 

[Cruiserdrew]

@Cruiserdrew - what fuse type and fuse holders do you use at the battery?

I've been using ANL fuses, with holder from Blue Sea, but I think the MBRF fuses are better. Unfortunately less common, so you'll need to have spares on board, but they install right at the battery, and completely protect the wire run.

 

[little_joe]

X2. What you want to do is easy. I recommend you do it in stages so it isn't too much at once.

@Cruiserdrew this is one the most straight-forward, easy-to-understand explanations I've run across. Thank you very much for this!

I am going this route, and already have the 8ga run to a fuse panel in the interior. The BlueSea 7610 ACR is en route. I have one extremely stupid question, though (suspend logic for a moment):

If the starting battery should get drawn down, can you jump it off the other battery w/o causing any damage or having to do anything weird? I realize I could just switch batteries in order to start/drive, but am just curious...

 

[Cruiserdrew]

Yes-You can just jump it by jumping only the (+) battery posts.

Thank you for the kind words. PM if questions about the install.

 

[TonyP]

Check out the Redarc BCDC1225, it'll do a lot of what you're asking in a small package. I ran one and was happy with it. It can't charge via 120VAC though.

 

[RFB]

X2. What you want to do is easy. I recommend you do it in stages so it isn't too much at once.

Start with your dual battery combiner. I like the BlueSea ACR. It's a bidirectional charging relay that senses charging voltages and automatically combines the batteries. That solves your problem of charging both batteries. That means your alternator is capable of charging both batteries when underway, and your solar can charge your aux, then once it's charged will combine and top your main. Pretty slick. When it isn't charging, like when parked and the fridge is running, it separates both batteries. THere is lots of talk about which one to use-I have found the 7610 to be perfect for normal Land Cruiser use and have 3 installed in 3 different trucks. The one in my FJ60 is 4 years old and has been perfect. And BlueSeas warranty is "as long as you own it", not to mention it is super efficient when closed. Other systems like IBS, NatLuna, and TMax use far more power to keep the relay closed-an important consideration when on solar and you don't have a ton extra to work with!

Any solar charge controller will work. You only need 1. The Morningstar Sunsaver 10 or 20 is excellent, reliable and robust. The 10 is enough for up to 175 watts of panel or so. You want it near the battery if possible, but I have my charge controller inside the cab these days and back charge through the interior fuse panel. Your solar panel can be the folding type or any flat panel mounted on the roof. Folding 100 watt is a good place to start. I have pretty much gone to a roof panel of 160-180 watts. Plenty of power for 2 fridges. If you want to monitor your charging with blue tooth, the Victron 75/15 discussed here is great.

It's worth the effort to have an interior fuse panel. So a largish wire (i used 8 gauge) runs from your aux battery, to your interior fuse panel. Then your interior loads get run from that. So radios, fridge, lighting all run off the interior panel.

To charge from a 120V source you will need a charger-You probably don't need an RV 50 amp charger so something like this would work:
https://www.amazon.com/NOCO-GENM2-W...30888751&sr=8-2&keywords=boat+battery+charger

It will be hard to find a shop to do this, or at least do it well. You might consider doing it yourself so you know how it works.

Make sure all of your main wires are fused at the battery. The MRBFs are great for this.


So your steps:
1-Install #2 battery, with combiner relay and cabling
2-Add interior fuse panel
3-Add Solar charging
4-Add onboard 120v charging if desired.

does this bad boy handle and disperse solar charge aso or just battery battery 120v in??

 

[Cruiserdrew]

does this bad boy handle and disperse solar charge aso or just battery battery 120v in??

It does fine with solar charge into the AUX battery. In fact, that's normal. And when the #2 battery is fully charged, it will top the starting battery too, without affecting the #2 battery.

But any charge source on either battery above 13.0 volts, will cause the relay to close and combine both batteries and charge. Doesn't matter if a 12 volt input from a solar source or a 12 volt input from a 120 source. Mine run on both all the time.

 

[LBeckons]

X2. What you want to do is easy. I recommend you do it in stages so it isn't too much at once.

Start with your dual battery combiner. I like the BlueSea ACR. It's a bidirectional charging relay that senses charging voltages and automatically combines the batteries. That solves your problem of charging both batteries. That means your alternator is capable of charging both batteries when underway, and your solar can charge your aux, then once it's charged will combine and top your main. Pretty slick. When it isn't charging, like when parked and the fridge is running, it separates both batteries. THere is lots of talk about which one to use-I have found the 7610 to be perfect for normal Land Cruiser use and have 3 installed in 3 different trucks. The one in my FJ60 is 4 years old and has been perfect. And BlueSeas warranty is "as long as you own it", not to mention it is super efficient when closed. Other systems like IBS, NatLuna, and TMax use far more power to keep the relay closed-an important consideration when on solar and you don't have a ton extra to work with!

Any solar charge controller will work. You only need 1. The Morningstar Sunsaver 10 or 20 is excellent, reliable and robust. The 10 is enough for up to 175 watts of panel or so. You want it near the battery if possible, but I have my charge controller inside the cab these days and back charge through the interior fuse panel. Your solar panel can be the folding type or any flat panel mounted on the roof. Folding 100 watt is a good place to start. I have pretty much gone to a roof panel of 160-180 watts. Plenty of power for 2 fridges. If you want to monitor your charging with blue tooth, the Victron 75/15 discussed here is great.

It's worth the effort to have an interior fuse panel. So a largish wire (i used 8 gauge) runs from your aux battery, to your interior fuse panel. Then your interior loads get run from that. So radios, fridge, lighting all run off the interior panel.

To charge from a 120V source you will need a charger-You probably don't need an RV 50 amp charger so something like this would work:
https://www.amazon.com/NOCO-GENM2-W...30888751&sr=8-2&keywords=boat+battery+charger

It will be hard to find a shop to do this, or at least do it well. You might consider doing it yourself so you know how it works.

Make sure all of your main wires are fused at the battery. The MRBFs are great for this.


So your steps:
1-Install #2 battery, with combiner relay and cabling
2-Add interior fuse panel
3-Add Solar charging
4-Add onboard 120v charging if desired.

Real cool, I have a 100w panel and my aux battery is in the back isolated. I'm thinking about moving it to the engine bay and would live something like this. I'm not getting enough sun to charge my battery with the current weather, is it optimal to have to of the same battery or can I keep my whatever starter battery and tie in my 100amp hour AGM, or do I need matching batteries?

 

[glocker21]

Thinking about 2 battery system for 15 LX570 to essentially run a fridge off of while camping. Off grid camping, charged with solar. On grid camping charged at campsite power (Battery tender or plug into battery charging system used for solar?). The reason I wouldn't use solar on-grid is it's usually forest camping in north GA, so can' be guaranteed sun on campsite.

List of needs for far: Solar Panel, deep cycle battery, 2 battery kit from one of a few places, and refrigerator.

I am unclear on charge controllers for 2 batteries, charging from solar and/or AC on those parts. Anyone do anything like this or can list parts I might need? Any vendors around Atlanta do this kind of work?

You might want to consider the KISAE DMT1230 Abso 30A DC-DC Battery Charger. It acts as a beetery isolator and MPPT charge controller that you can use with Solar as well as charging via your alternator. They make the DMT1250 as well that has a 50A output current. both the 30a and 50a are user selectable ( DMT-1230 30A / 20A / 10A / 5A (User Selectable) and the DMT-1250 5-50A (5A Step - User Selectable)

 

[meatloaf]

@Cruiserdrew, any advantage in using the Blue Sea ACR 7622 over the ACR7610 other than having the in cab control? I am looking to run a dual battery system and I like your idea of keeping it simple.

Thanks!!

 

[Cruiserdrew]

@Cruiserdrew, any advantage in using the Blue Sea ACR 7622 over the ACR7610 other than having the in cab control? I am looking to run a dual battery system and I like your idea of keeping it simple.

Thanks!!

The in cab control is cool (though failure prone at the switch) and the self jump is theoretically cool(though I've never needed that feature). But the 7610 is smaller, less expensive, less complicated and works extremely well. I installed the first one in 2015 and it's still going strong in my FJ60. I have 3 in service and will continue to recommend them without reservation.

 

[meatloaf]

Thanks @Cruiserdrew ! Which batteries are you using or have you used? A lot of posts here on mud say you have to use similar batteries on both sides?

 

[Cruiserdrew]

I use Marine Start/DeepCycle batteries. I do not use $$ batteries. THe ones from batteries plus work pretty well.