80 series dual battery question
- Thread starter KE5QVT
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ntsqd
Heretic Car Camper
Have you searched the 80 Series 'Mud section? I know of a couple installs documented over there.
Otherwise the prime thing is how you're going to wire the batteries. Manual switch, automatic switch, solenoids of many different flavors, direct, etc.
My own preference is for a Voltage Sensing Relay (VSR) (sometimes referred to as an Automatic Charge Relay or "ACR") in parallel with a manual marine battery combiner switch, but there are many other ways that are equally right depending on your preferences.
Otherwise the prime thing is how you're going to wire the batteries. Manual switch, automatic switch, solenoids of many different flavors, direct, etc.
My own preference is for a Voltage Sensing Relay (VSR) (sometimes referred to as an Automatic Charge Relay or "ACR") in parallel with a manual marine battery combiner switch, but there are many other ways that are equally right depending on your preferences.
flyingwil
Supporting Sponsor - Sierra Expeditions
Tom,
In the winter edition of Overland Journal they did a Dual Battery System Review. They tested and rated the Hellroaring System, National Luna, Painless, Perfect Switch, SurePower, Wrangler NW, and Xantrex battery isolator/combiner units. The National Luna was selected as Editor's Choice, and the Value Award went to the Xantrex units. I personally use a National Luna kit and think the Xantrex is a great because it offers a number of features not found on even the National Luna, such as adjustable voltage cut-in and higher amperage capabilities. However, the Xantrex units are being discontinued however Xentrex will continue to provide warranty coverage on the units.
In the winter edition of Overland Journal they did a Dual Battery System Review. They tested and rated the Hellroaring System, National Luna, Painless, Perfect Switch, SurePower, Wrangler NW, and Xantrex battery isolator/combiner units. The National Luna was selected as Editor's Choice, and the Value Award went to the Xantrex units. I personally use a National Luna kit and think the Xantrex is a great because it offers a number of features not found on even the National Luna, such as adjustable voltage cut-in and higher amperage capabilities. However, the Xantrex units are being discontinued however Xentrex will continue to provide warranty coverage on the units.
spressomon
Expedition Leader
The new Power Gate dual battery isolator/rectifier has kept my 100 series batteries protected: Reliable, small form factor, virtually no wasted current, runs cool and no mechanical/moving parts. Just works.
Pskhaat
2005 Expedition Trophy Champion
I have a simplified system. The 80 has an "alternator good" line that asserts after the engine is up, running, and the alternator is up to voltage into which you can tap at the port-side fender and feed to a relay to connect a primary and auxiliary battery. Getting a full system is generally a better option but I've been running the aforementioned setup for about 11 years without issue.
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Mlachica
TheRAMadaINN on Instagram
I've ran a perfectswitch in my tacoma and now I run it on my 80 and love the simplicity. The install is a little more involved but it's not too bad at all. It takes little space and there's no moving parts.
I've also installed the National luna kit on my brother's 100 series. It's really easy to install and comes with nearly everything you need for the install except the batteries and tools to do it. I like the theory behind the isolator.
Check out my install in thread, the link is in my sig.
And do a search on the forum, you'll find plenty of info. Don't forget the OJ article as well.
I've also installed the National luna kit on my brother's 100 series. It's really easy to install and comes with nearly everything you need for the install except the batteries and tools to do it. I like the theory behind the isolator.
Check out my install in thread, the link is in my sig.
And do a search on the forum, you'll find plenty of info. Don't forget the OJ article as well.
LC/LR4Life
Adventurer
I'd get the PowerGate system. Google em up and give em a call.
cruisertoy
Explorer
Being a newby on the dual battery systems, I guess my question is this: Are all the expensive monitors.... worth the extra expense? I realize there is peace of mind knowing that the lights are on and at any moment you know the status of both batteries. Besides some little lights and an alarm on some of the units, why wouldn't someone just use a Rectifier or solenoid to charge both batteries and put a manual switch under the hood in order to jump from the Aux battery to the main battery if needed? I subscribe to the KISS method most of the time, so is there a simple way to do the dual battery without all the bells. Basically just a bomb proof, leave it alone to do it's job system. Again, I'm a newby so be easy on me. My subscription to OJ doesn't start until this next issue so I missed the whole dual battery writeup.
RoundOut
Explorer
The system I installed is pretty much what you described. I have a combiner switch inside the cab that is a "DPDT Center Off" switch. It uses the center position as stock, one on position to combine the batteries when the key is in the "accessory" or "run" position, and the other on position to combine the batteries all times. The switch powers a solenoid that does the actual combining. Problem is, there is no way to gauge the voltage of just the secondary battery, no way to automatically prevent overcharging of the secondary battery, and no way to trickle charge the secondary battery. I plan on installing some fixes for these deficiencies in the future, but for now, I just manually switch it to the on position for a few minutes every week.
One note on something you mentioned... Consider locating your combiner switch in the cab instead of under the hood. That way, it is accessible to you without getting out.
.
cruisertoy
Explorer
Couldn't you buy an external voltage regulator and put it after the relay? I know on my fj40 the original electrical system had an external regulator that was fairly cheap. This should regulate the second battery just as your altenator regulated the first.
ntsqd
Heretic Car Camper
My basic premise in everything that I do is to not leave myself traps to fall into. If everything is manually operated and I forget to do one of them, then that's a "trap." Some things I only want to operate manually, but there are things that should happen without my oversight. Like battery charging.
Diode bridge isolators are a nice idea with one large pitfall. There is a voltage penalty for crossing the bridge. Unless the charging system's regulator is adjusted to offset this loss the batteries will never get fully charged. I experienced this in an early dual battery system that I had in my '66 Econoline van. The batteries always were down, and at the time I didn't understand the problem.
I see the VSR/ACR's as an automated version of the simple continuous duty solenoid method. They do not combine the batteries until the starting battery has reached a set level of charge. So they're like a person sitting there watching the voltage level of the starting battery and then throwing the switch when it has reached some given voltage level, rather than simply coming on when the ignition is turned on.
For me, having a manual battery combiner switch under the hood instead of remoted to the dash means that I'm much less likely to forget that the batteries are combined and run down both of them. Some folks want that control on their dash, but for me that is a recipe for eventual disaster as that switch will get bumped to some unintended setting and not noticed until there's a problem.
Charge regulators, whether internal or external, vary the excitation voltage of the alternator's field to control voltage output. There can only be one of that style of regulator per alternator.
When paired, thru any method that does not cause a voltage difference between the batteries, the regulator will 'see' both the combined voltage of both batteries and not over-charge either battery. If there is a voltage drop or resistance of any significance in the cables to a battery, then that battery will look artificially low to the regulator, and it will attempt to charge it up to the correct voltage. So classically over-charging of only one of several batteries is not the fault of the regulator, but of the cabling and related hardware.
Diode bridge isolators are a nice idea with one large pitfall. There is a voltage penalty for crossing the bridge. Unless the charging system's regulator is adjusted to offset this loss the batteries will never get fully charged. I experienced this in an early dual battery system that I had in my '66 Econoline van. The batteries always were down, and at the time I didn't understand the problem.
I see the VSR/ACR's as an automated version of the simple continuous duty solenoid method. They do not combine the batteries until the starting battery has reached a set level of charge. So they're like a person sitting there watching the voltage level of the starting battery and then throwing the switch when it has reached some given voltage level, rather than simply coming on when the ignition is turned on.
For me, having a manual battery combiner switch under the hood instead of remoted to the dash means that I'm much less likely to forget that the batteries are combined and run down both of them. Some folks want that control on their dash, but for me that is a recipe for eventual disaster as that switch will get bumped to some unintended setting and not noticed until there's a problem.
Charge regulators, whether internal or external, vary the excitation voltage of the alternator's field to control voltage output. There can only be one of that style of regulator per alternator.
When paired, thru any method that does not cause a voltage difference between the batteries, the regulator will 'see' both the combined voltage of both batteries and not over-charge either battery. If there is a voltage drop or resistance of any significance in the cables to a battery, then that battery will look artificially low to the regulator, and it will attempt to charge it up to the correct voltage. So classically over-charging of only one of several batteries is not the fault of the regulator, but of the cabling and related hardware.
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