Dump Trailer - How many dumps before battery is dead?

[Skyco]

I did replace the deep cycle marine battery with a dual purpose marine battery. Its made for starting and deep cycle and give the best of both worlds.

There ya go...I thought about that after I posted my bit about deep cycle vs starting batteries. For the record my 6x12 14,000 GVWR dump trailer came with a deep cycle, when it goes south it probably will get a starter battery (cheaper) or maybe the dual use (costs more) type:thumbsup:

BTW one online source says to use a deep cycle as a starting battery it need to be 20% larger for the same high amp draw.

 

[Eagleview]

I didn't read all the post's so please forgive if it has been stated .

You are simply draining the batteries way faster than they could possibly be recharged . The only real way to do it is to run heavy leads , permanent or with spring clamps from your tractor battery to the trailer battery . The alternator will then be doing most of the work helped by the batteries .

 

[Dmace]

I've posted this before but here it is again- I do NOT think a deep cycle battery is the best for a dump trailer. Why? A deep cycle is best at providing relatively small amounts of current over a long period. What is a starting battery best at? Providing large amounts of current for a short period.

Now think about a dump trailer- large amounts of current needed for a short period. Sometimes several hundred amps. Hmmmmm......

Regardless of the type of battery the OP's problem is to be expected...frequent dumping will take a LOT of battery capacity.

A Deep Cycle battery is simply a different type of plate which is solid vs. a "sponge-like" plate in Starting batteries. Now when you use a dump trailer, the typical raise cycle probably takes 15-30 seconds depending on load. That length of draw on a battery will easily drain it down to about 20%-40% of it's capacity which is EXACTLY what a deep cycle battery is for. A starting battery is only made to be drawn down to about 85-90% of it's capacity for a very short time (a couple of seconds max) before recharging. This is the opposite of what a dump trailer will do. Running a Starting battery on a dump trailer will NOT last as long as a Deep Cycle simply because it will be "deep-cycled" almost every time you lift the dump and that is NOT what a starting battery is made for.

For the record, Marine batteries are a "hybrid" of starting and deep-cycle batteries.

Thanks Dmace,

But will a charge system develop 13-14 volts at idle.

I know for a fact most small engine systems, like a motorcycle, will not.

You have to idle them up at least to 1500-2000 rpm to get that reading.

It depends on the vehicle but it should be reading at least 12.1 to 13 volts while idling and go up to 14.0 or more when at half the engine's rated rpms. For comparison, my 03 Dodge Ram idles at 750 rpms and produces 13.2 volts at the battery while idling and 14.6 volts at 2500 rpms. My Harley Dyna 1340cc idles at 1100 rpms and produces 13.2 volts idling and 14.5 at 3000 rpms.

 

[Skyco]

Check your math!
A typical battery is 100 amp hours.
So- lets say -worst case- one draws 200 amps for 30 seconds or seen another way 1/120 of an hour.
That isn't gonna take the battery down to "20%-40% of it's capacity" In fact a good battery, ie not worn out or defective, should do this many times before reaching even 40% of capacity.

And your statement- "For the record, Marine batteries are a "hybrid" of starting and deep-cycle batteries."

You can fix that for you by adding the word some after the first comma.
"Marine" batteries are available in 3 types- deep cycle, starting, and dual purpose starting/deep cycle.

I agree with Diamondpilot the "marine dual purpose" batteries are probably the best way to go. Especially if one is dumping a lot without recharge between cycles. Some deep cycle batteries just simply aren't designed to put out the massive current needed for a dump trailer. As I said one source says to use a 20% greater size battery if using a true deep cycle battery as a "starting" or dump trailer lifting battery.

Now personally I haven't used my dump trailer to dump frequently without recharge, I always have a road trip to get more material to bring it back up before the next cycle.

 

[JFS2295]

>>> I've sometimes will dump a load every 10-15 minutes.

As another poster stated, it sounds like you are using it more as a dump truck then what a dump trailer was intended for.

An electric/hydraulic power source even with stout storage backing is limited. If this was me and I was going to use the dump function as much as you do I would consider eliminating it altogether and go to a gas or diesel hydraulic power supply. You would have full capacity whenever you need it.

 

[Dmace]

Check your math!
A typical battery is 100 amp hours.
So- lets say -worst case- one draws 200 amps for 30 seconds or seen another way 1/120 of an hour.
That isn't gonna take the battery down to "20%-40% of it's capacity" In fact a good battery, ie not worn out or defective, should do this many times before reaching even 40% of capacity.

You can do all the "math" you want. A dump trailer WILL drain a battery more than 10-15% very easily. 5-10 loads with only a brief charging while the truck is running will easily drain the battery to half it's capacity. A starter battery just is NOT made for that kind of drain on a regular basis and will not last as long as a deep cell in that environment. Yes you do need to oversize the deep cell battery by 15-20% compared to a starting battery but it will still work better and last longer.
I guarantee a starter battery would not last nearly as long as my deep cell with all the cycles I put it through in my dump trailer. REAL WORLD experience not "math".

 

[zman007007]

DING DING DING Round 2 LOL calm down fellas :confused2:

 

[AlanB]

OP,

Have you gone back and verified that you are getting 12 volts + (whatever your charging cycle is) back there to your battery?

Every now and then we will blow a fuse, get a bad connection etc. and find that my charge from my truck is not making it's way back to the trailers battery.

Bad ground on trailer last time, bad connection on truck jack time before, blown fuse time before.

Make sure everything that is already there is working properly before getting too carried away.

We normally have longer drive cycles with ours (commercial use) but seldom have problems that it just won't work. Usually it is minor failures in the system.

Hope you get it sorted out.

 

[Cat_Driver]

Something is wrong. There are days I dump all day long every hour on multiple days and have never had a battery go down? Mine charges from the pigtail from the truck

 

[Skyco]

Unfortunately, discharge curves aren't linear. A battery is rated by a certain standard with a specified discharge current to achieve its rating. Discharge it less, and it will last longer. Discharge it with a heavier load, and it will last less that its rating.

Quite true. My problem was the implication one 15 to 30 second cycle will bring a starting battery down to 20-40% of capacity. Obviously repeated cycles can do this.

One thing I found researching all this is it is really impossible to properly charge a deep cycle battery from a vehicle! Deep cycle type batteries need a sequence to do it right, solved by plugging it in to a 3 step charger when finished using it for the day.

I picked up an interesting device yesterday on close out ($15 WalMart) - it is a Black and Decker "jump starter" device designed to plug into the cig lighters of two vehicles. It contains an invertor that takes the approx 12v from the donor vehicle and steps it up to a claimed 14.5 VDC at 8A to bring up the battery in the recipient vehicle.
Initial stumbling block is it has a 20 minute timer...I need to open it up and see if I can disable the timer or change it to a much longer interval. Might be an interesting solution to low charge output available at most 7 pin trailer sockets without the expense and difficulty of running heavy cables.