Dual Battery: National Luna or IBS kit? (1 Viewer)

[SupraTuRD]

Very little design needed. Really, this is easy.
1-Mount the ACR somewhere convenient. The back of the #2 battery box is a good spot for a 7610, or on the firewall
2-Connect the grounds of both batteries together. #2 Cable works perfectly
3-Connect + terminal of one battery to the big terminal of the ACR Again, #2 cable
4-Connect the + terminal of the second battery to the other big terminal of the ACR #2 cable
5-Connect the ACR negative terminal with small fused wire to ground of #1 battery
6-Go have a nice microbrew

Note: you will want to fuse your + cables at the battery. I like the MRBF form Blue Sea, or ANL fuses in a quality holder. With 2 gauge wire, 150 amp fuses will be about right.

I have ACRs on 3 trucks, all working perfectly. Can't say enough good things. If you come through Sac, I'd be happy to help you make up cables-I have a mondo crimper for large cables that doesn't get enough use.

Thanks for the great information @Cruiserdrew !

I am currently in the process of installing the 7622. The instruction says to "use circuit protection only if ACR is not used for emergency cross-connect."

I'm assuming this is in reference to pushing the red button to connect the two batteries for a self jump start.

I understand that the 150A fuses may be adequate, but how does this setup work with a 12k winch that can draw close to 400A connected unfused to the start battery?

Thanks in advance.

 

[SupraTuRD]

Thanks for the great information @Cruiserdrew !

I am currently in the process of installing the 7622. The instruction says to "use circuit protection only if ACR is not used for emergency cross-connect."

I'm assuming this is in reference to pushing the red button to connect the two batteries for a self jump start.

I understand that the 150A fuses may be adequate, but how does this setup work with a 12k winch that can draw close to 400A connected unfused to the start battery?

Thanks in advance.

The scenario that worries me is winching a heavy load while combining the two batteries.

 

[Cruiserdrew]

Your choice, fuses or wires! Much safer to blow fuses. You could upsize the wire to 1/0, and fuses to 250 or so. That will be fine.

Actually just looked it up-it looks like you could fuse 1/0 to 285 amps with a margin of safety.

Remember that there is a time delay built into when a fuse will blow-ie not instantly. Even a 150 amp fuse will handle 300 amps for a time.

Here is a trip time delay graph for Blue Sea 150 amps fuses:

 

[Cruiserdrew]

And remember too, you can winch just fine off just the main battery. The scenario of having to winch with both batteries is like an almost never event.

 

[LC4LIFE]

I am getting ready to install the 7610, but am curious if there is anyone that just grounded the second battery to the engine block rather than the other battery (like the ACR instructions say to) or if there is a downside to doing it that way.

 

[Cruiserdrew]

I am getting ready to install the 7610, but am curious if there is anyone that just grounded the second battery to the engine block rather than the other battery (like the ACR instructions say to) or if there is a downside to doing it that way.

Will work fine. It's just that battery to battery is convenient. Can also do both, which is what I have done.

 

[RFB]

Ive got IBS with dual batteries and a snorkel. CD is right the blue sea unit is way more reliable the IBs has a battery monitor and with the rms is able to jumpstart your own battery but Ive already cooked the realy doing some wiring so dual odysseys extremes and aux fan, 4 sets of seperate switched rigids and a 50 in light bar and a fridge and 1000 watt inverotr, but I travle long stretches alone and need the gear. its not cheap you need to know your wiring(all mine myself) the NL or IBS if I didnt have IBS already installed I would have gone blue sea. my two pieces of copper clad zinc also I do have the SLEE relaocation wiper kit. and I always carry an extra relay, IBS is anything special except is 50 more than a regular relay.

 

[RFB]

How much #2 Wire should I order? Black & Red Colored Wire?

I ordered up the Blue Sea 7610, Crimps, and the OEM Battery Box, Will handle the Washer Relocation and bend battery hooks out of 1/4-20 All-Thread, Already cut the Angle that holds the battery out of Aluminum.

If you going to do it order up 12 and 12 red and black I cant tell you how much heavy guage wire my fj has in it now, always a need JMO

 

[dugsgms]

Forgive my ignorance on the subject but was thinking of addidng a second battery for the winch and inverter and was thinking of using the cole hersee 48530 48530 - Smart Battery Isolators Series - Battery Isolators from Battery Management - Littelfuse. Are there any disadvantages to using this as compared to others mentioned?

 

[SupraTuRD]

Your choice, fuses or wires! Much safer to blow fuses. You could upsize the wire to 1/0, and fuses to 250 or so. That will be fine.

Actually just looked it up-it looks like you could fuse 1/0 to 285 amps with a margin of safety.

Remember that there is a time delay built into when a fuse will blow-ie not instantly. Even a 150 amp fuse will handle 300 amps for a time.

Here is a trip time delay graph for Blue Sea 150 amps fuses:

Thanks Drew. So in the case of using a winch with your outlined setup with the 2 awg cables and 150A fuses, would we want to isolate the two batteries manually when using the winch (assuming that the winch is connected to the start battery with the appropriately sized cables)? This way all of the current to the winch would come from the start battery only... am I understanding this correctly?

 

[Cruiserdrew]

Thanks Drew. So in the case of using a winch with your outlined setup with the 2 awg cables and 150A fuses, would we want to isolate the two batteries manually when using the winch (assuming that the winch is connected to the start battery with the appropriately sized cables)? This way all of the current to the winch would come from the start battery only... am I understanding this correctly?

You don't need to. As the voltage drops with a high load, the ACR will sense this and open itself thus separating the batteries. I think anytime the voltage in the system is below 12.75 volts, the relay opens.

 

[SupraTuRD]

You don't need to. As the voltage drops with a high load, the ACR will sense this and open itself thus separating the batteries. I think anytime the voltage in the system is below 12.75 volts, the relay opens.

I believe there's a time delay built in so the automatic isolation might not happen right away.

 

[Dave 2000]

I believe there's a time delay built in so the automatic isolation might not happen right away.

Correct, the time delay will cause load to be seen across two batteries. I simply placed cube fuses at the terminals, this also protects the cable in the event of a front end shunt, neat, simple and reliable.............you know just in case.

Regards

Dave

 

[86tuning]

....
I understand that the 150A fuses may be adequate, but how does this setup work with a 12k winch that can draw close to 400A connected unfused to the start battery?....

The scenario that worries me is winching a heavy load while combining the two batteries.

My winch is connected to the primary battery. Under winching loads, the batteries may disconnect, IMO, not a big deal. Whatever happened when I only had one battery? As for batteries sharing the load, the winch may draw 400A, of which ~80A is supplied by the alternator, and the batteries supply the other 320A, split in two, so ~160A each. The math works out fine.

FWIW my dual battery setup isn't fused between the batteries. FWIW your factory single battery setup isn't fused between the starter and the battery either. And my winch wires aren't fused at all. So in a bad enough collision, If the wires are cut, there may be a fire. Oh well. Good thing the 2/0 winch wiring has heavy heavy insulation on it. Too bad it runs to the front bumper.

Edit: Also, what everybody said about using marine equipment. There is no substitute for the Blue Sea ACR units. They're awesome. Good enough for million dollar boats. Good enough for my priceless 80.

I am getting ready to install the 7610, but am curious if there is anyone that just grounded the second battery to the engine block rather than the other battery (like the ACR instructions say to) or if there is a downside to doing it that way.

Mine's grounded to the engine block, and to the fender. Since the charging current is from the alternator (bolted to the engine) it makes more sense to me, along with the shorter wires. There's already enough going on at the start battery terminals for me to not want to go there

 

[PabloVTA]

need to re-name this thread to @Cruiserdrew 's Dual Battery Kit and FAQ.

 

[shadowsixniner]

I've had the IBS system installed for the last 3 years and it is rock solid! Yes you pay a few more bucks, but it has never let me down. My AGM deep cycle battery is always charged up and the manual boost feature is nice if your main battery dies. 10/10

 

[Dave 2000]

My winch is connected to the primary battery. Under winching loads, the batteries may disconnect, IMO, not a big deal. Whatever happened when I only had one battery? As for batteries sharing the load, the winch may draw 400A, of which ~80A is supplied by the alternator, and the batteries supply the other 320A, split in two, so ~160A each. The math works out fine.

FWIW my dual battery setup isn't fused between the batteries. FWIW your factory single battery setup isn't fused between the starter and the battery either. And my winch wires aren't fused at all. So in a bad enough collision, If the wires are cut, there may be a fire. Oh well. Good thing the 2/0 winch wiring has heavy heavy insulation on it. Too bad it runs to the front bumper.

Edit: Also, what everybody said about using marine equipment. There is no substitute for the Blue Sea ACR units. They're awesome. Good enough for million dollar boats. Good enough for my priceless 80.

The mathS would be right in the perfect world but unfortunately this is not the case.

Voltage drop across cables between batteries, your 80 amp alternator will not be supplying 80 amps, so a little re-think needed here.

Re Blus Seas gear you are spot on, see my thread link in Sig, I have been rating them for years.

Regards

Dave

 

[willbt]

Hey Guys, awesome information in here. ...And sorry to revive an old thread, but I have a question.

If I were to install the BlueSea ACR 7622 unit, do I have to install the remote switch? It seems that I can control the ACR using the lockout knob on top of the unit itself, yes? From reading the BlueSea instructions for this ACR, it seems that if I were to need to self jump, I could just press the yellow knob button while in the Remote position and this will combine the Starting and House batteries, correct?

 

[Dirty Koala]

Hey Guys, awesome information in here. ...And sorry to revive an old thread, but I have a question.

If I were to install the BlueSea ACR 7622 unit, do I have to install the remote switch? It seems that I can control the ACR using the lockout knob on top of the unit itself, yes? From reading the BlueSea instructions for this ACR, it seems that if I were to need to self jump, I could just press the yellow knob button while in the Remote position and this will combine the Starting and House batteries, correct?

You don't need to use the remote switch, that is just for conveniance.

 

[shadowsixniner]

Lots of good options and recommendations in this post. I have been using IBS's system for the last 4 years and it has never given me an issue to this day. If I was to do do it all over again though I would try the Blue Sea ACR and see how it goes. It doesn't have the in cab display but as mentioned there are other ways around that if you want to check your battery voltage levels.