Opinions on Dual Battery Systems (NL vs. IBS vs. T-Max vs. BlueSea, etc.) - Looking to get one soon

[Mogwai]

Question, what are folks running that such large gauge battery cables are needed? I'm pretty sure most standard batteries themselves charge at something like... 5amps. AGM may charge at 30 to 40 amps? Winches are connected directly to batts. Fridges run at low amps, etc... What is it that's making it so higher than 2 gauge wire is needed? For example, 2 gauge at 8ft (the longest run) is only a .43 percent voltage drop. Anything below 2% is considered acceptable in the marine world. Plus, amp ratings are for continuous use, they can handle much more at peak for short periods of time (start for example). For reference OEM is like... 4 gauge.

And believe me, I'm all for overkill in the right situations!

 

[TonyP]

I'm considering the CTEK system. It not only manages charging from the alternator but can manage solar too. Pretty cool system. Not cheap though.

 

[elkeye]

Question, what are folks running that such large gauge battery cables are needed? I'm pretty sure most standard batteries themselves charge at something like... 5amps. AGM may charge at 30 to 40 amps? Winches are connected directly to batts. Fridges run at low amps, etc... What is it that's making it so higher than 2 gauge wire is needed? For example, 2 gauge at 8ft (the longest run) is only a .43 percent voltage drop. Anything below 2% is considered acceptable in the marine world. Plus, amp ratings are for continuous use, they can handle much more at peak for short periods of time (start for example). For reference OEM is like... 4 gauge.

And believe me, I'm all for overkill in the right situations!

I wanted to avoid the cost of having to replace 'undersized' cable!

Winches can draw up to 400 amps and these amps are typically supplied by the running alternator, the primary battery & the auxiliary battery (if linked).



IBS recommends for their 200 amp/12v dual battery system:


A direct connection of the minus pole of both batteries by a copper cable will improve the efficiency of the battery system. Use same wire section as used on plus cable connections. The chassis of the vehicle isn't good enough as conductor.


For 4WD's 25 mm² and with winches 35 mm² should be used. In vehicles for rally competition a section to 50 mm² may be useful.


FAQ's for IBS-DBS/DBi - IBS




Interestingly, IBS does not appear to indicate the max. wire length for the recommended wire section (mm2)!

While the longest run in a LC200 may be 8-11ft, you have to double that distance when calculating the voltage drop because of the by-pass wire between the negative terminals of the starter battery and auxiliary battery.

Calculate the wire size required to carry 100 amps @ 12-14 volts over the length of a cable measuring from your primary battery to the secondary battery and back (with a 2-3% voltage loss in the cable).

Calculate the wire size required to carry 150-200 amps @ 12-14 volts over the length of a cable measuring from your primary battery to the secondary battery and back (with a 2-3% voltage loss in the cable).

The cost difference between 2 AWG and 1/0 AWG (50 mm2) copper cable (or 1/0 AWG and 2/0 AWG copper cable) is not significant when considering the total cost of a dual battery system.

 

[elkeye]

I'm considering the CTEK system. It not only manages charging from the alternator but can manage solar too. Pretty cool system. Not cheap though.

What are the dimensions of the CTEK system you are considering? Where do you plan on mounting the CTEK system?

 

[Mogwai]

I wanted to avoid the cost of having to replace 'undersized' cable!

Winches can draw up to 400 amps and these amps are typically supplied by the running alternator, the primary battery & the auxiliary battery (if linked).



IBS recommends for their 200 amp/12v dual battery system:


A direct connection of the minus pole of both batteries by a copper cable will improve the efficiency of the battery system. Use same wire section as used on plus cable connections. The chassis of the vehicle isn't good enough as conductor.


For 4WD's 25 mm² and with winches 35 mm² should be used. In vehicles for rally competition a section to 50 mm² may be useful.


FAQ's for IBS-DBS/DBi - IBS




Interestingly, IBS does not appear to indicate the max. wire length for the recommended wire section (mm2)!

While the longest run in a LC200 may be 8-11ft, you have to double that distance when calculating the voltage drop because of the by-pass wire between the negative terminals of the starter battery and auxiliary battery.

Calculate the wire size required to carry 100 amps @ 12-14 volts over the length of a cable measuring from your primary battery to the secondary battery and back (with a 2-3% voltage loss in the cable).

Calculate the wire size required to carry 150-200 amps @ 12-14 volts over the length of a cable measuring from your primary battery to the secondary battery and back (with a 2-3% voltage loss in the cable).

The cost difference between 2 AWG and 1/0 AWG (50 mm2) copper cable (or 1/0 AWG and 2/0 AWG copper cable) is not significant when considering the total cost of a dual battery system.


View attachment 1418062

Hypothetically that all makes sense. My question was, what are you running that you need even 100 constant amps? Let alone up to 200? Winch gets connected directly to a battery, and through its own cables, and while the vehicle is running, is it common practice to connect, or disconnect the 2nd battery while winching? I've never heard of anyone having issues running a winch on a single OEM battery/alternator, and OEM cable is 4 gauge. I'm just curious is all..And I'm certainly no electrician. I know 1/0 is fairly standard around here but never really heard a good justification other than "it doesn't cost that much more". Maybe those who run huge amps for sounds systems?

 

[TonyP]

What are the dimensions of the CTEK system you are considering? Where do you plan on mounting the CTEK system?

In the bay somewhere. There's a fair bit of room in the 200's bay. Not a ton but enough for a CTEK (both modules), 2nd battery and wiring. Everything else (compressor, fuse box, ect) will be in the side compartments of my drawer system. On the roof I'm thinking a hard shell (Alu-Cab) with solar.

This is the CTEK I'm thinking. 100A Off Road - CTEK Battery Chargers

Apparently it boost the charge from a stock alternator too but I haven't done a ton of reading into it.

 

[TonyP]

Hypothetically that all makes sense. My question was, what are you running that you need even 100 constant amps? Let alone up to 200? Winch gets connected directly to a battery, and through its own cables, and while the vehicle is running, is it common practice to connect, or disconnect the 2nd battery while winching? I've never heard of anyone having issues running a winch on a single OEM battery/alternator, and OEM cable is 4 gauge. I'm just curious is all..And I'm certainly no electrician. I know 1/0 is fairly standard around here but never really heard a good justification other than "it doesn't cost that much more". Maybe those who run huge amps for sounds systems?

I agree with @Mogwai If you're pulling more than 100A from a single cable excluding winch support you need to rethink your plans. That's hardcore stuff. I'm a fan of overbuilding but that's out of the park. Also, keep in mind your linking techniques. Soldering isn't ideal for high amp applications. There's a reason battery cables and winches are crimped not soldered. Invest in a hydraulic crimper if you're planning on doing your own electrical work.

 

[Markuson]

Question, what are folks running that such large gauge battery cables are needed? I'm pretty sure most standard batteries themselves charge at something like... 5amps. AGM may charge at 30 to 40 amps? Winches are connected directly to batts. Fridges run at low amps, etc... What is it that's making it so higher than 2 gauge wire is needed? For example, 2 gauge at 8ft (the longest run) is only a .43 percent voltage drop. Anything below 2% is considered acceptable in the marine world. Plus, amp ratings are for continuous use, they can handle much more at peak for short periods of time (start for example). For reference OEM is like... 4 gauge.

And believe me, I'm all for overkill in the right situations!

Huge cables help minimize voltage drop. On my rig, I'm running a 1500 Sine Wave inverter waaaay in the back, and juuuuust manage to run what I want, despite the longer-than-recommended cable length (which also contributes to voltage drop). Fat cables drop less, and it's most often voltage drop--rather than lack of raw battery power--that shuts things down in back. I have 4 gauge running to the back, but should really have 2 or even zero. Luckily, I'm making it work well with 4. I can run a full power microwave back there if I want.

 

[beretta]

I recently finished my triple Oddesey setup utilizing a MOSFET dual rectifier from Power-Gate. I'm really happy with the results and reserve power that seems to be endless. Scott Stolper (@perfect switch) is much better than I at explaining why mosfet units are better at managing battery circuits than the others.
12 Volt & 24 Volt Battery Isolators | 100 - 600 Amp Currents

 

[mark71]

I recently finished my triple Oddesey setup utilizing a MOSFET dual rectifier from Power-Gate. I'm really happy with the results and reserve power that seems to be endless. Scott Stolper (@perfect switch) is much better than I at explaining why mosfet units are better at managing battery circuits than the others.
12 Volt & 24 Volt Battery Isolators | 100 - 600 Amp Currents

View attachment 1418333 View attachment 1418334 View attachment 1418335

Triple batteries?

Plans to become a hybrid cruiser?

Seriously, that's awesome!

 

[beretta]

Triple batteries?

Plans to become a hybrid cruiser?

Seriously, that's awesome!

I wish. I'd probably get better mileage.

 

[mark71]

I wish. I'd probably get better mileage.

Is that your final mounting solution, or do you have something planned?

 

[beretta]

Is that your final mounting solution, or do you have something planned?

Mounting location for which component?

 

[gaijin]

Mounting location for which component?

Let's start with your passenger side battery. It looks like it is held in place with zip-ties, but that can't be right, could it?