Dump Trailer

[SkunkWerX]

No criticism from me, PatG has given some very in depth info.
I was probably being a bit broad.

I also agree with Pat, you need some beefy wire gauge, not 12.

Think "jumper cable" gauge.

Even with the batteries in parallel, the draw will come from the place it's easiest and most readily available. Your Dump Battery won't be acting as any kind of fuse. If the dump battery is a little lower in power than the tractor battery, the current is going to flow from the tractor battery.

Example; with the current set-up, the Deep Cycle battery cannot give up enough current, rapidly enough for proper dumping, therefor, if you simply hooked your tractor battery in parallel, the dumper would draw a good portion of it's needs from the tractor, rather than the Deep Cycle.

 

[Iplayfarmer]

No criticism from me, PatG has given some very in depth info.
I was probably being a bit broad.

I also agree with Pat, you need some beefy wire gauge, not 12.

Think "jumper cable" gauge.

Even with the batteries in parallel, the draw will come from the place it's easiest and most readily available. Your Dump Battery won't be acting as any kind of fuse. If the dump battery is a little lower in power than the tractor battery, the current is going to flow from the tractor battery.

Example; with the current set-up, the Deep Cycle battery cannot give up enough current, rapidly enough for proper dumping, therefor, if you simply hooked your tractor battery in parallel, the dumper would draw a good portion of it's needs from the tractor, rather than the Deep Cycle.

I appreciate all the input. One thing that I think everyone is missing here is that the only time I had a problem with the dump was when the battery started to lose charge. The first few dumps were even with a partially drained battery due to a faulty charger (see post #286 ) and it still worked fine. Therefore the statement "the Deep Cycle battery cannot give up enough current, rapidly enough for proper dumping" is only true if the Deep Cycle battery is low on charge.

All I'm really looking for is a system to charge the battery rather than boost the power. I looked, and my battery is indeed a marine/RV battery, so it is a hybrid.

I'm sure that using 00 cable would be the least resistance, most efficient power transfer, and last the longest, but the cost of the wire, connectors, and couplers for it will likely outweigh the benefit. What I'm trying to reach here is an adequate compromise that will maintain the charge on the trailer battery throughout the few hours that it might be used.

Maybe what I'm looking for rather than solenoids or isolators is a system that limits the amps going to the battery such that there's sufficient to charge it after a dump, but not so much current during a dump that it will cause failure of the wiring.

The wiring on a camper trailer hook up that charges the trailer battery is not very heavy guage wire. How is that controlled?

 

[SkunkWerX]

I appreciate all the input. One thing that I think everyone is missing here is that the only time I had a problem with the dump was when the battery started to lose charge. The first few dumps were even with a partially drained battery due to a faulty charger (see post #286 ) and it still worked fine. Therefore the statement "the Deep Cycle battery cannot give up enough current, rapidly enough for proper dumping" is only true if the Deep Cycle battery is low on charge.

All I'm really looking for is a system to charge the battery rather than boost the power. I looked, and my battery is indeed a marine/RV battery, so it is a hybrid.

I'm sure that using 00 cable would be the least resistance, most efficient power transfer, and last the longest, but the cost of the wire, connectors, and couplers for it will likely outweigh the benefit. What I'm trying to reach here is an adequate compromise that will maintain the charge on the trailer battery throughout the few hours that it might be used.

Maybe what I'm looking for rather than solenoids or isolators is a system that limits the amps going to the battery such that there's sufficient to charge it after a dump, but not so much current during a dump that it will cause failure of the wiring.

The wiring on a camper trailer hook up that charges the trailer battery is not very heavy guage wire. How is that controlled?

Marine/Starting is what it should say. Marine/RV just means Deep Cycle. In RV's they call them "coach" batteries, meaning to run your lights and such.

Your tow vehicle will put a charge your Deep Cycle while you are working.
Then you will have to do a real charge to bring the Deep cycle back up to full.

 

[Iplayfarmer]

I looked at the fine print, and the battery says it's a "dual purpose deep cycle and marine starting battery"

 

[SkunkWerX]

I looked at the fine print, and the battery says it's a "dual purpose deep cycle and marine starting battery"

Starting!!! that's the word! Good deal.
Those are nice batteries.

OK, back to charging. The idea being, you can charge the battery at your garage over night. [x] check.

But, each time you dump, you are robbing the battery of some charge. Taking money out of the bank, so to speak. If it were only a few dumps, then you could simply charge it back up when it was parked. but if you are working on a good size project, numerous loads, there is a point of diminishing returns.

By hooking up to your towing vehicle (tractor's) system, you can be putting some money back into the bank while you are driving back and forth doing the dump work.

As PatG described, there are ways to wire this set up, such that, you don't drain your tractor's battery inadvertantly.

An inexpensive isolator is an easy thing to wire into the system. Allows the DUmp Battery to charge, but won't allow the tractor's battery to be sucked down.

Bottom line, you can have the tractor charging the Dump Battery while the tractor is running.

 

[2manyrocks]

On an RV, you get more of a slow trickle type charge when the RV is plugged into campground power. The RV can also be charged from the tow vehicle.

There is a very good book on RV electric power, batteries and charging methods. Sorry, I don't remember the name right off. It's been a while since I read it, but I think it said to use good quality batteries and that the most efficient and quick charging would be via the tow vehicle because of the higher amp input from the vehicle versus campground power.

The "isolation" unit you could get from an RV dealer at an high price or might find elsewhere for cheaper. RV campers want to avoid having the tow vehicle battery drained to nothing by the camper.

 

[mopacman]

My JD 140 has car battery in it. I would get a cheep set of jumper cables and hook to the tractor. That way you would have two batterys to run the trailer and use the charging system to charge both of them. Keep the tractor running at half RPM should help because the JD does not have an automotive alternator that puts out a lot at idle. The only reason you need a batt. isolater is to keep your batt. from running down when you are camping and cant start you truck to get home....Larry

 

[mopacman]

A way to reduce amp draw on the on the batt. would be use two cylenders. This would cut your Hydrolic pressure in half and amp draw in half. and make your lift operate half speed. If your pump slows down when at high pressure this might keep the pressure low enough to keep the speed up to make up for the slower dump speed. By doing this it would be better on the pump and batt......Larry

 

[sandman2234]

Sounds good, using two cylinders, but he already has the trailer built, so we are just trying to figure other ways to make what he has built work.
Sure wish you had been around when I built mine, as I had a pair of cylinders and a single scissor lift type cylinder. I went with the single, but often wish I had gone with the two and got more stability in the side to side motions.
David from jax

 

[Iplayfarmer]

A way to reduce amp draw on the on the batt. would be use two cylenders. This would cut your Hydrolic pressure in half and amp draw in half. and make your lift operate half speed. If your pump slows down when at high pressure this might keep the pressure low enough to keep the speed up to make up for the slower dump speed. By doing this it would be better on the pump and batt......Larry

The specs on the pump actually say that it can be adjusted for a higher pressure, lower flow. That may be an option. Thanks for that input.

 

[patrick_g]

I suspect that being of above average intelligence the owner of the VERY NICE little dumper will not ordinarily start out with a discharged battery. If that is a reliable assumption then the solenoid/relay approach is the better choice by far.

In RV applications the diode isolator is typically better so that the users of the lights, heater fan, TV, etc don't run the vehicles starting battery down (you don't usually park overnight with the engine running.)

Normal ops with the dumper will work fine with a charge line significantly lighter in gauge than jumper cables. With jumper cables you could probably eliminate the dumper's battery. I still recommend 6 ga as able to handle enough current to help out a little (8 may be OK too and you will not have a self destruct mechanism at 10 ga but please use at least 8... multi strand of course) The 6 or 8 will be more than adequate for charging while driving from A to B and let the alternator and tractor batt help some during a lift.

You don't actually absolutely have to have the solenoid as there is no big penalty for just connecting the two batts in parallel with 6 or 8 ga wire. You will probably seperate the two and not leave the two batteries hooked up together all the time.

There is a small difference in final charging voltage between the normal starting batt and a deep cycle or maint free. For that reason the two batteries should not be left connected together when a batt maintainer (little wall wart I recommended) or other trickle charger is left connected for an extended period. For the times when the two are connected together and being worked and driven around there will be nothing to worry about regarding the different final charge voltage. I assume you won't be using the dumper for more than intermittent service for periods not to exceed 12-14 hours without a break!!!

Hope this has helped. If any of this is of further interest and not explained clearly, ask questions and I'll try to be more clear.

Oh, and one other thing... for completeness and to address some wrong info posted. Which ever batt is charged the most does NOT mean that it will supply all the power to run the system. The more fully charged batt will be discharged into the less charged and the result will be less power available than before the interconnection (batts are not 100% efficient.) In normal use (with the 8 or 6 ga interconnect) the batts will track each other in voltage quite closely, within a small fraction of a volt. A few feet of #6 can conduct MUCHO amps before it drops more than a couple tenths of a volt.

Reader's Digest version: When connecting the dumper to a tow vehicle, connect the tow vehicles 12 volt batt to the dumper's 12 volt bat (in parallel) using #6 or #8 multistrand wire for both positive and negative, avoiding using the hitch for a ground connection. Disconnect the interconnection when placing the dumper's deep cycle batt on a maintainer (wall wart.)

Pat

 

[Iplayfarmer]

I suspect that being of above average intelligence the owner of the VERY NICE little dumper will not ordinarily start out with a discharged battery. If that is a reliable assumption then the solenoid/relay approach is the better choice by far.

In RV applications the diode isolator is typically better so that the users of the lights, heater fan, TV, etc don't run the vehicles starting battery down (you don't usually park overnight with the engine running.)

Normal ops with the dumper will work fine with a charge line significantly lighter in gauge than jumper cables. With jumper cables you could probably eliminate the dumper's battery. I still recommend 6 ga as able to handle enough current to help out a little (8 may be OK too and you will not have a self destruct mechanism at 10 ga but please use at least 8... multi strand of course) The 6 or 8 will be more than adequate for charging while driving from A to B and let the alternator and tractor batt help some during a lift.

You don't actually absolutely have to have the solenoid as there is no big penalty for just connecting the two batts in parallel with 6 or 8 ga wire. You will probably seperate the two and not leave the two batteries hooked up together all the time.

There is a small difference in final charging voltage between the normal starting batt and a deep cycle or maint free. For that reason the two batteries should not be left connected together when a batt maintainer (little wall wart I recommended) or other trickle charger is left connected for an extended period. For the times when the two are connected together and being worked and driven around there will be nothing to worry about regarding the different final charge voltage. I assume you won't be using the dumper for more than intermittent service for periods not to exceed 12-14 hours without a break!!!

Hope this has helped. If any of this is of further interest and not explained clearly, ask questions and I'll try to be more clear.

Oh, and one other thing... for completeness and to address some wrong info posted. Which ever batt is charged the most does NOT mean that it will supply all the power to run the system. The more fully charged batt will be discharged into the less charged and the result will be less power available than before the interconnection (batts are not 100% efficient.) In normal use (with the 8 or 6 ga interconnect) the batts will track each other in voltage quite closely, within a small fraction of a volt. A few feet of #6 can conduct MUCHO amps before it drops more than a couple tenths of a volt.

Reader's Digest version: When connecting the dumper to a tow vehicle, connect the tow vehicles 12 volt batt to the dumper's 12 volt bat (in parallel) using #6 or #8 multistrand wire for both positive and negative, avoiding using the hitch for a ground connection. Disconnect the interconnection when placing the dumper's deep cycle batt on a maintainer (wall wart.)

Pat

Well, there's the answer to the original question: #6 or #8 wire. Of course I learned a lot in the mean time as usual.

I've got a 1.5 amp trickle charger/maintainer that I plan to use for keeping it charged when it sits.

 

[SkunkWerX]

Well, there's the answer to the original question: #6 or #8 wire. Of course I learned a lot in the mean time as usual.

I've got a 1.5 amp trickle charger/maintainer that I plan to use for keeping it charged when it sits.

It appears that we are back around to the simple umbilical hook-up that was recommended a while back. It should work fine. As PatG stated, the assumption is that they will be uncoupled unless actually in use.

As long as you begin with a dump battery that has been charged, you will be fine, as the tractor will only be replenishing the charge that is drawn by the dump motor each time it cycles. Once both batteries are wired together (with proper gauge wire), they are acting more like one battery, with a one key fact still remaining, the electrons will flow via the path of least resistance, ie; the easiest path.

When we were thinking you had strictly a deep cycle, it was looking like the path of least resistance may have been the tractor battery, as a strictly deep cycle battery would not pass the high current demanded by the pump motor as easily as a starting battery.

Now that we know you have a Deep Cycle Starting battery that concern is pretty much old news.

I'll still recommend the trolling Motor Male/Female connectors for their relative stoutness/gauge/ and economy. I have used them in these types of battery-to-battery and battery-to-load appllications and they do a good job.
They make for an easy plug-in operation when you are ready to hook-up.

You will probalby find them with pigtails as large as 8 ga.

Good Luck and let us know how it goes.
You have a great Dump trailer there!

 

[patrick_g]

with a one key fact still remaining, the electrons will flow via the path of least resistance, ie; the easiest path.

Excellent advice in all respects except one small technical nit which we seem to be hung up on.

The dumb wires and electrons don't act like a computer.

One of my favorite Einstein quotes is: "Make everything as simple as possible, but no simpler. I don't always achieve this but it is of interest.

The statement "Electricity takes the path of least resistance" is often made and nearly as often shouldn't be made and is frequently just not true or is not the whole story!

Electricity takes all available paths, including the one of least resistance but not excluding others.

If electricity "O N L Y" took the path of least resistance then you could only have one light or appliance on at a time because only one of the loads could be the path of least resistance. In a car you could only have one light on at a time and blowing your horn might turn off the radio or ignition coil. This is not the case.

Current flow is proportioned according to resistance in the parallel branch circuits. Similarly both batteries in the setup discussed here make a contribution. The way they share the load differs depending on their internal resistance, and external resistance (connecting wires.)

In the attached drawing (If it got attached) you see a batt and three loads in parallel (typical way they are used.) Meter #1 will register all the amps flowing from the battery which will equal the sum of the amps flowing in each of the three parallel circuits.

You will NOT see the current taking (just) the path of the least resistance. You will see the total current flow divided proportionally between all the parallel circuits in inverse proportion to the resistances of the individual loads.
Resistance total is equal to 1/(1/R1 + 1/R2 + 1/R3)

Total current is equal to the battery voltage divided by the total resistance as figured with the above method.

Similarly if there are multiple batteries in a circuit the current is apportioned according to the resistances. Batteries have internal resistance. This is what causes them to not be able to supply infinite amps.

Deep cycle batts have higher internal resistance and so will supply less amps when heavily loaded. combo batts, i.e. deep cycle and starting rated batts have lower internal resistance and plate construction to support some high current draw as well as deep cycle action. They are neither fish nor fowl neither a really good deep cycle batt nor a really HD starting batt but are sometimes the compromise you need.

With the tow vehicle batt and alternator connected to the dumper batt with some decent wire the dumper batt will be helped during a lift. if the wire used is too small the resistance will prevent the alt and veh batt from helping as much. Between lifts the charge rate of the dumper batt will not be so critically effected by wire size selection (12 ga vs 6 or 8) since the current will be much less.

If it were mine I'd use a couple runs of 6 but 8 will be pretty good. 10 or 12 ga wire won't save enough money to warrant losing much of the assistance of the alternator and tow vehicle batt. Again, use multistrand.

Pat

P.S. I wouldn't leave a 1 1/2 amp maintainer hooked up ad infinitum to the dumper battery. The el cheapo units supply less than an amp and are much less likely to cause a long term problem (under $10 at HF on sale) I have a good US made 1 1/2 amp maintainer and it is OK for my dual batt setups on my diesels but I prefer the little ones for long term use on single batts.

 

[currierej]

I'm following, this represents a lot of my thoughts.

 

[John_Mc]

P.S. I wouldn't leave a 1 1/2 amp maintainer hooked up ad infinitum to the dumper battery. The el cheapo units supply less than an amp and are much less likely to cause a long term problem (under $10 at HF on sale) I have a good US made 1 1/2 amp maintainer and it is OK for my dual batt setups on my diesels but I prefer the little ones for long term use on single batts.

The better quality ones are fine to leave connected long term. Unlike the cheaper ones, which put out that current constantly, the better "smart chargers" continuously sample the battery and adjust as necessary so they won't boil off your electrolyte or otherwise damage the battery. I've been using several BatteryMinder smart chargers of various sizes for years with good results (including a specialty charger left connected almost all the time to a $500+ 24V aircraft battery).