Charging batteries while driving?
- Thread starter dawsonc61
- Start date
teotwaki
Excelsior!
maybe tell us a little more.
What vehicle do you have?
How many amps can the alternator handle?
Are the two yellowtops in addition to your vehicle's main battery?
Are the two yellowtops located in a trailer, pickup bed or....?
How much current will be pulled from the yellowtops while charging them?
What vehicle do you have?
How many amps can the alternator handle?
Are the two yellowtops in addition to your vehicle's main battery?
Are the two yellowtops located in a trailer, pickup bed or....?
How much current will be pulled from the yellowtops while charging them?
I'm definitely a noob when it comes to most things electrical, especially DC. I didnt know if i just needed a hot wire from the car battery or alternator to a DC battery charger (if the is such a thing).
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teotwaki
Excelsior!
"Noob" is A-okay on this forum. We are all here to share and learn.
Please answer my initial questions as best as you can so that I can try to help you. We would want to connect a wire to your alternator but don't want to overload it. Your alternator is the DC battery charger in your car.
Most important:
- What vehicle do you have?
- What engine?
- Are the two yellowtops in addition to your vehicle's main battery?
- Are the two yellowtops located in a trailer, pickup bed or....?
We can figure these out next:
- How many amps can the alternator handle?
- How much current will be pulled from the yellowtops while charging them?
Casper
Adventurer
Not trying to be mean, but he did answer the initial questions you asked. They are the red part in his post above yours. (sorry, I missed it the first time as well) :coffeedrink:
Casper
:smiley_drive:
teotwaki
Excelsior!
No not mean... I'm just stupid (LOL):elkgrin:
Sorry! Maybe I should have increased the font size! I'll try to answer the questions I didn't know.
78Bronco
Explorer
Are you talking about a dual battery setup like this
http://www.sleeoffroad.com/technical/tz_dual_batteries.htm
There are other systems out there aswell that will put a toggle swicth in your cab so you don't need the giant marine battery switch in the system.
http://www.redarc.com.au/smart_battery_isolators.htm
http://www.sleeoffroad.com/technical/tz_dual_batteries.htm
There are other systems out there aswell that will put a toggle swicth in your cab so you don't need the giant marine battery switch in the system.
http://www.redarc.com.au/smart_battery_isolators.htm
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teotwaki
Excelsior!
Okay, with my ears red, I'll start over with the answers that were provided
2003 Jeep Wrangler Rubicon 4.0 L
The two yellowtops are located in the tounge box of my trailer
I'm sure other Expo folks can chime in so let's start with a general layout.
Some casual Googling says the alternator may be rated at 117 Amps. Keep in mind that it has to run your engine and charge the battery under the hood too.
A really simple system would be to connect to the battery with a large 4 gauge cable and a large amperage fuse, maybe 100 Amps. From there you'll want some decent large gauge (4 to 8) stranded cable to run along the frame and back by your towing receiver. At that point you'll want a good connector (exact type to be determined but see pix). On your trailer you could use a simple diode type battery isolator to connect the two batteries to the charging line. I would put additional in line 60 Amp fuses, one on each battery.
diode isolator
quick connect plug
http://www.moroso.com/catalog/categorydisplay.asp?catcode=42224
car audio typical 100 Amp fuses and holder available at auto stores
http://cgi.ebay.com/4-8-GAUGE-AGU-F...in_0?hash=item1c0c3972cb&_trksid=p4999.c0.m14
There are lots of dual battery threads on the forum that have lots of info in them.
2003 Jeep Wrangler Rubicon 4.0 L
The two yellowtops are located in the tounge box of my trailer
I'm sure other Expo folks can chime in so let's start with a general layout.
Some casual Googling says the alternator may be rated at 117 Amps. Keep in mind that it has to run your engine and charge the battery under the hood too.
A really simple system would be to connect to the battery with a large 4 gauge cable and a large amperage fuse, maybe 100 Amps. From there you'll want some decent large gauge (4 to 8) stranded cable to run along the frame and back by your towing receiver. At that point you'll want a good connector (exact type to be determined but see pix). On your trailer you could use a simple diode type battery isolator to connect the two batteries to the charging line. I would put additional in line 60 Amp fuses, one on each battery.
diode isolator
quick connect plug
http://www.moroso.com/catalog/categorydisplay.asp?catcode=42224
car audio typical 100 Amp fuses and holder available at auto stores
http://cgi.ebay.com/4-8-GAUGE-AGU-F...in_0?hash=item1c0c3972cb&_trksid=p4999.c0.m14
There are lots of dual battery threads on the forum that have lots of info in them.
teotwaki
Excelsior!
It looks as if he will have three batteries total, one under the hood and two back in his trailer.
Maybe throw a solar panel on the trailer to help keep the batteries topped off?
78Bronco
Explorer
It would depend on how much draw the batteries will require when you start charging them. I would go with the quick disconnect shown on the previous page. The big plug will ensure no melt downs during heavy charging tasks.
Here is a chart that will show you the size of wire to use over distance based on amperage draw.
http://www.offroaders.com/tech/12-volt-wire-gauge-amps.htm
The batteries in the trailer can be wired together constantly.
I've heard bad things about the diode isolators frying and killing batteries and vehicle electronics.
I would go with the redarc system so you can switch the charging function off while the engine is not running. If you kill you vehicle battery while out in the boonies you can connect the batteries in the trailer for jump starting just by flipping the switch.
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Bullseye240
Adventurer
I agree with this one and you can make a set of jumper cables that plug into it by simply buying two sets of the plugs. Then you dont have to open your hood to give someone a jumpstart. I have that setup on my Blazer and love it. People are always impressed with it when I don't open the hood to start theirs.
ntsqd
Heretic Car Camper
I am going to guess that the two batteries in the trailer are wired in parallel as a single battery bank, and can be treated (for a simple system) as one very large battery.
The reason for asking how much current is being drawn off the batteries while they are being charged is that what ever this current is directly subtracted from the charging current. Say that the trailer has a fridge in it. That means that the trailer battery(ies) have current demand of somewhere between 2 amps and 20 amps and those amps will not be used to charge the battery(ies).
The 7 pin trailer light connectors have a terminal for charging any trailer battery. This is a quite common feature of the larger RV type trailers. The problem with using this method of connection is that the terminal size limits the current to about 10 amps maximum. That is normally OK, you just won't be self jump-starting through that small of a connector.
The diode bridge type of isolator can result in poor battery life unless equipped with a voltage sensing terminal. Diodes have a "cracking voltage" which is the minimum voltage that has to be applied for them to turn on. This voltage is lost, it never makes it to the battery(ies), which reduces the maximum charge potential. In general more sophisticated battery management has moved away from using diodes.
My own preference is to use a "Voltage Sensing Relay" also known as an "Automatic Charge Relay." These devices sense primary battery voltage and allow it to be recharged after starting before connecting the trailer/auxiliary battery(ies) to the alternator.
http://www.delcity.net/store/Voltage-Sensing-Relay-!-Single-Sense/p_793852.a_1
http://www.westmarine.com/webapp/wc...rue&storeNum=5002&subdeptNum=9&classNum=12106
The reason for asking how much current is being drawn off the batteries while they are being charged is that what ever this current is directly subtracted from the charging current. Say that the trailer has a fridge in it. That means that the trailer battery(ies) have current demand of somewhere between 2 amps and 20 amps and those amps will not be used to charge the battery(ies).
The 7 pin trailer light connectors have a terminal for charging any trailer battery. This is a quite common feature of the larger RV type trailers. The problem with using this method of connection is that the terminal size limits the current to about 10 amps maximum. That is normally OK, you just won't be self jump-starting through that small of a connector.
The diode bridge type of isolator can result in poor battery life unless equipped with a voltage sensing terminal. Diodes have a "cracking voltage" which is the minimum voltage that has to be applied for them to turn on. This voltage is lost, it never makes it to the battery(ies), which reduces the maximum charge potential. In general more sophisticated battery management has moved away from using diodes.
My own preference is to use a "Voltage Sensing Relay" also known as an "Automatic Charge Relay." These devices sense primary battery voltage and allow it to be recharged after starting before connecting the trailer/auxiliary battery(ies) to the alternator.
http://www.delcity.net/store/Voltage-Sensing-Relay-!-Single-Sense/p_793852.a_1
http://www.westmarine.com/webapp/wc...rue&storeNum=5002&subdeptNum=9&classNum=12106
Awesome info guys, I appreciate it. Yes The batteries are going to be run in paralell and yes I will have a fridge running while driving. It's the new 50 qt ARB but I'm unsure how many amps it draws. I will probably run these plugs:
I like the idea of rigging up a set of cables that plug in instead of messing with the hood. One of my buddies did this with his dual battery setup in his jeep. I also like the idea of being able to jump myself by plugging the jeep to the trailer! Very cool!
Like I said before, Thanks for all the ideas!
I like the idea of rigging up a set of cables that plug in instead of messing with the hood. One of my buddies did this with his dual battery setup in his jeep. I also like the idea of being able to jump myself by plugging the jeep to the trailer! Very cool!
Like I said before, Thanks for all the ideas!
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