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View Full Version : Power needs for work Sprinter.. I'm new. :-)


Who8TheHam
08-07-2010, 06:58 PM
Hi all. I am a very new Sprinter owner. I just bought my 2007 Sprinter Wagon (144" High top van) and would like to furbish it with a desk and some shelves for my Mobile Sharpening Business. That part is simple enough. However, I know absolutely nothing about power needs. As far as I know it has the factory battery which is under the seat. There is a flat-like item with attached wires, etc. in the engine compartment where I suspect an additional battery can go. I do not know what that is. The previous owner installed a 19" DVD system and a 300W inverter in the passenger area. My question is this:

I plan on operating a plain ole' 100W swing arm magnify light that will be on whenever I am working. In addition, I would like to have enough power to operate a low-budget belt grinder/polishing machine if needed. IS the current set-up viable for my power needs? The grinder will only be used for a few minutes at a time and will not be used a lot I suspect. I was considering a larger inverter but don't know if I would need more batteries. If so, I have no way to charge batteries overnight as I live in a community where I dont have access to power. I was also looking into "quiet generators (i.e Honda 2000is)" but dont like the noise idea. My budget is around $600 US. Any suggestions? Thanks a bunch!!!

-Joey-Bag-O-Doughnuts

"If it aint broke, don't fix it....." Huh? Then where is all the fun?

piper1
08-08-2010, 03:31 AM
A 1500W inverter and 1 extra battery should do the trick. You can buy a decent group 31 size AGM battery from a big truck dealer and mount it and the inverter under your grinder. You may be able to get away with a smaller inverter but start up loads from electric motors are kinda tough on inverters so going a bit bigger than you need helps them last.

I would recommend hooking your extra battery to the main battery under the drivers foot area and installing a high amperage circuit breaker in the line somewhere that can act as a shut off as well (keep you from killing the main bat). These are available from truck dealers and some electric supply places (and likely on e-bay). 100 amp will do just fine.

Battery can be had for around 200, inverter for 2-300 (varies greatly) and the big circuit breaker likely for 50-100. A bit of heavy guage wire and ends and your off to the races.

NelsonSprinter
08-08-2010, 05:55 PM
:2cents: I wouldn't recommend putting an extra battery under the grinder. Batteries produce Hydrogen gas and a spark from the grinder may produce an unwanted explosion inside. :yell: Oh the HUMANITY'
If you can get a lower powered bulb like an incandescent 25W or LED 10W with as much light as the 100W, you will save the battery plenty!
YOU NEED to tell us the wattage or amps of the grinder to know if the invertor is enough for your needs. :thinking:
It never hurts to add a battery, but a 'deep cycle' is needed not a truck battery. :thumbdown:

knighty
08-09-2010, 12:18 AM
could you not get a 12v or 24v grinder ?

that makes things much easier, that way you can power it straight from a big battery/a couple of big batteries (if it's 24v you need a charging gizmo, but they're small/easy/cheap :-)

(could also use a 12v/24v light to match)

you could even buy a mains grinder, and swap the motor over for a 12v/24v one

Who8TheHam
08-09-2010, 12:38 AM
Thanks all for the info but I am worried about the 'charging' aspect of having more than one battery. I do not have access to charging at night as my Sprinter is parked on a busy street and not near a garage. And I don't believe I would be driving enough between jobs for the alternator to charge all batteries efficiently. Of course I say this without having any idea of what I am saying. :-P Please help

:cheers:

seans
08-09-2010, 12:43 AM
You stated your requirements well; this should be pretty easy.


As far as I know it has the factory battery which is under the seat.


I think you're on the edge as to whether you need a second battery. You might be better off with an auxiliary battery, battery isolator, and sufficiently sized (and short) cables to power an inverter. The risk is that if you use it while the vehicle is off, you'll be draining your main vehicle battery, and its life may be much shorter. If you pull too much current when the engine is running, you might shorten the life of the alternator. Being stranded because of the battery or alternator would erase the savings of not installing a second battery, isolator, and sufficiently sized cables. You will probably want to go this route if you plan to have an assistant (who may not follow precautions to prevent battery or alternator problems) operate this stuff eventually.

But if you are frugal with power, and can take precautions, it might work out fine. If you want to try the one-battery route, you might also invest in a clamp-on DC ammeter from Sears (about $70 IIRC.) You could then get the inverter and see if using it with all other accessories off and the van running exceeds the current handling capacity of the alternator. If not, you might be good to go without the second battery.


I plan on operating a plain ole' 100W swing arm magnify light that will be on whenever I am working. In addition, I would like to have enough power to operate a low-budget belt grinder/polishing machine if needed.


It is important to keep your AC loads as light as possible, and it seems like you're going to do that.

The areas where you may be challenged will be the higher current requirements to start the grinder motor, and how much current it requires to keep it running once started. Do you know this? Multiply by 10-12 and this is the current the inverter will require from the 12V system.


The grinder will only be used for a few minutes at a time and will not be used a lot I suspect.


This is good; the less you use it, the better it will be. You should turn everything off as soon as you no longer need it.


I have no way to charge batteries overnight as I live in a community where I dont have access to power.


You will need to be able to drive enough to keep everything charged; again, the need for conserving power.


I was also looking into "quiet generators (i.e Honda 2000is)" but dont like the noise idea.


And mounting it will be expensive.


My budget is around $600 US.


Which is why I did not suggest solar cells or other things to address this.

As for an inverter, maybe you can be our guinea pig and try out the Xantrex ProWatt 2000. This should be more than enough to start your grinder motor. It also has a relatively low current draw when there is no load (but you still want to turn it off when not using it.) I think the ProWatt 1000 may be too small.

This model is new, and some of us want to know how well it works. It is a pure sine wave inverter. It looks like they can be found on Google for under $400. Up until recently, pure sine wave inverters were MUCH more expensive than this! I would not recommend using a modified sine wave inverter for driving your grinder motor. Let us know how it works out.

You should mount the inverter as close to the battery as possible, and run wires to it that are as thick as possible, since big wires are needed to carry the large current required to start and run your grinder motor. Put the inverter where it is closest to your power source, since it is much easier to run lightweight extension cords from your inverter to your tools than run heavy expensive battery wire from your inverter to your battery.

With the engine running, you can clamp the ammeter to the cable between the battery and alternator, and find how many amps are pulled with different loads (AC, lights, etc) turned on and off. Then turn on the inverter and grinder and see how much it adds.

I will go out on a limb and say that if you cannot shave enough loads to keep the current draw to no more than 75% of the alternator rating (assuming that alternators must be derated when they get hot, and honestly, 75% is a guess, it may be too low or too high) then you should invest in an AGM house battery, tie-downs to keep it secure in an accident, and a battery isolator that disconnects it if it draws too much current. That might push you a little over your limit.


"If it aint broke, don't fix it....." Huh? Then where is all the fun?


With that attitude, I can suggest you try the single battery solution first, because if you measure properly you might not break things, and if things break, you'll have lots of fun when it comes time to replace your battery and/or alternator (it is not hard to do yourself, but the alternator is not cheap.)

icarus
08-09-2010, 12:48 AM
Go test fire a honda eu 1000 or 2000 or even 3000 depending on your peak load. These generators are so quite that you won't be able to hear them over the grinder noise. The 1000 will use less than 1/4 of a gallon of fuel in 4 hours at half load. The 2000 a bit more. They can be had new for under $1000 used for half that. the 1000 weights ~29 lbs, the 2000 perhaps 40.

Comes under the category of KISS. Couldn't be easier.

Icarus

Aqua Puttana
08-09-2010, 02:08 AM
Who8theham,
Nice name by the way.

There's lots of great information about Sprinter power options in the replies to this thread and even more if you search from the blue bar above now that you have a starting information base.

What comes to my mind when someone says mobile sharpening service is kitchen knives, mower blades, scissors and other relatively small items. Mower blades being one of the big ones. If that is the case maybe my comments apply, if not just ignore them.

I checked Sears because I have a very small but effective bench grinder I bought there many, many years ago. I carried it with me when I pretended to do repairs out of a Walk-in van. It was very light duty, but did 99% of what I ever needed.

A search shows they no longer carry the model I have, but they do have one that looks interesting to me.

25388

http://www.sears.com/shc/s/p_10153_12605_00912800000P?prdNo=13&blockNo=13&blockType=G13

A grinder starts in much the same mode as a fan. There is really not a heavy prolonged loading as the motor rotates the wheels up to speed. The heavy load comes on if the material is held hard against the wheels and they slow down. So what I'm saying is that the start currents are not extremely high and of a long duration as they would be with an air compressor for instance.

I think if you stay with a small grinder you will find a very large inverter and battery system will not be necessary.:2cents: Have fun. vic

With that attitude, I can suggest you try the single battery solution first, because if you measure properly you might not break things, and if things break, you'll have lots of fun when it comes time to replace your battery and/or alternator (it is not hard to do yourself, but the alternator is not cheap.)
Sean,
You're pulling the typical "vic" sarcasm faux pas. You forgot the :bounce: :hugs: :thumbup: stuff with the sarcasm. vic::clapping::cheers:

piper1
08-09-2010, 03:28 AM
I wouldn't recommend putting an extra battery under the grinder. Batteries produce Hydrogen gas and a spark from the grinder may produce an unwanted explosion inside. <snip>
It never hurts to add a battery, but a 'deep cycle' is needed not a truck battery. :thumbdown:

If he goes to a truck dealer and asks for an AGM battery they will sell him a Deep Cycle or perhaps Dual Purpose battery (either will work) and it will be a "nice" size and cheap. AGM's also produce negligible amounts of hydrogen as their design uses any hydrogen produced to re-wet the internals (what little liguid there actually is). AGM's will only vent hydrogen if they are over charged for lengthy time periods, hence they are quite common now in new trucks for their inherent safety (mount right in the bunk in some cases). AGM's also accept charge very quickly to an 80% level meaning with the appropriate size cable and depending on how low the OP drains it, it could have sufficient charge to be re used in less than 1 hour. As mentioned before, a group 31 AGM is cheap, so if it does get ruined by constant under charging, it's cheaper to recycle it and get a new one than employ expensive flooded batteries that need to be baby sat.

I'd much rather have an isolated extra $150 battery than place an inverter load on my slightly more than $150 Sprinter electrics on a regular basis.

Just my :2cents:.

nebep
08-09-2010, 03:41 AM
I have a 2000W Tripp-Lite inverter, powered by a Optima Yellow top.

I use a RYOBI bench grinder off of that day in and day out. It does well.

Definitely look into an LED rig of some sort for your lighting. I'm sure it's out there, you just might have to do some digging.

Another option may be a CFL lighting setup. 100W equiv. would be about 30W actual draw if I'm not mistook...This would help.

On this particular truck, I have a solenoid tied to the ignition, so, when the truck is started, the circuit allows current to flow from the front to the back battery.

How long is each stop? Most of the time I'm not stopped for very long and just let the truck idle. I think my back battery in this truck is about done - it has served well for about 7.5 years.

Since all equipment is 110V - I have a way to disconnect the inverter and use "shore power" if it's readily available and I may be sitting still for a while at one place.

seans
08-09-2010, 01:30 PM
Sean,
You're pulling the typical "vic" sarcasm faux pas. You forgot the :bounce: :hugs: :thumbup: stuff with the sarcasm. vic::clapping::cheers:
Yes, I forgot the smilies :bash: Nothing but love in these forums :hugs:

What I liked about Who8TheHam's signature is that it sounds like he's willing to experiment and find out what works :cheers: even if occasionally an experiment fails resulting in some extra expense :cry: which is how I've been doing it as I build out my van :professor: though some of the failures, while educational, came with a price tag (new alternator) :bash: but also led to my acquisition of some tools I've wanted for a long time (Honda eu2000i generator, for example) :bounce:

Aqua Puttana
08-09-2010, 09:42 PM
Yes, I forgot the smilies :bash: Nothing but love in these forums :hugs:

What I liked about Who8TheHam's signature is that it sounds like he's willing to experiment and find out what works :cheers: even if occasionally an experiment fails resulting in some extra expense :cry: which is how I've been doing it as I build out my van :professor: though some of the failures, while educational, came with a price tag (new alternator) :bash: but also led to my acquisition of some tools I've wanted for a long time (Honda eu2000i generator, for example) :bounce:
Sean,
Very gentlemanly of you to re-issue and ham it up for him... us. :thumbup: :hugs: :clapping: :bounce: :cheers: :lol: :laughing: :smirk: :rad: :tongue: :professor: :D: :drink: :popcorn:

:whistle: vic

Who8TheHam
08-12-2010, 04:40 PM
All great replys folks. Thank you greatly!! I took all your suggestions into consideration and have thus far done the following: I found an energy saver 42" reach shop-light with 7" magnifyer that only uses three 9W high efficeint bulbs. Huge Wattage savings there. I also found a fan (for comfort) at Walmart that only draws .6 amps at 120V (72 Watts???) which will be much cheaper than an air conditioning unit (I live in Southern Calif where there is'nt much humidity). In additon, I've been looking at the Ryobi 4 x 36 in Belt/Disc Sander from Home Depot that uses only 4.3 AMPs (or approximately 516 Watts). I will use shore power as much as possible while working (close to a home, alley behind restaurant, etc.). So now I am looking into a 1000 watt sine wave inverter or the Honda 2000 IS Super Quiet Inverter Generator. I will keep you posted and thanks for all the great ideas!! -Joe.