AC power supply in an ammo can (from car battery)

[KeepOnTruckin]

On Totse, some dude put an car battery, an inverter, and some sort of AC power thing in a 50 cal ammo can. I really want to make one of these. Can someone provide the pictures or instructions?

Actually I think it was a marine battery- better suited for long current draws.

[Virus]

On Totse, some dude put an car battery, an inverter, and some sort of AC power thing in a 50 cal ammo can. I really want to make one of these. Can someone provide the pictures or instructions?

Actually I think it was a marine battery- better suited for long current draws.

There's no way in hell you're going to fit a 12 volt marine battery into a .50 BMG Ammo can or even a 20mm Grenade can for that matter.

As for making a portable 120 V AC power source, buy a deep cycle 12 volt battery, and an inverter that fits your needs. I'd then rig it to where one DPDT missile switch controlled the circuit from the batterey to the inverter. From there I would build a custom box out of non conductive material such as wood and have the outlets exposed, but covered by an external outlet cover required by code on houses.

Of course the entire thing will weigh greater than 50 pounds, but if you really want to that's what I would do.

[MunkeyQ]

There won't be any step-by-step instructions as it's very simple and will vary greatly depending on what inverter and battery you have. All you have to do is buy a suitable battery, a small inverter and connect the two together. By "AC power thing" I'm guessing you mean a socket on the outside.

As Virus said, you haven't got much chance of stuffing a marine battery inside an ammo case. Being metal and conductive isn't an issue unless you're an ass and don't bolt anything down - if it's going to be moved around, everything should be secure inside.

Your best bet is to find two or more smaller deep-cycle traction batteries, which can be positioned in the box with greater flexibility. Get sealed ones or ventilate the box well as you really, really, don't want hydrogen building up inside - when lead-acids are charged or heavily discharged, each cell vents small amounts of hydrogen.

No lead acid battery likes being completely discharged, so make sure your inverter has a low voltage cut-off to prevent this. Most decent ones shut down at 11.1 volts to make sure you can start your car again. It's a good idea to put a fuse directly after the batteries so you don't burn things if something goes wrong - and as Virus suggested, put a switch in the DC line before the inverter so it doesn't drain the battery slowly when not in use.

[KeepOnTruckin]

There won't be any step-by-step instructions as it's very simple and will vary greatly depending on what inverter and battery you have. All you have to do is buy a suitable battery, a small inverter and connect the two together. By "AC power thing" I'm guessing you mean a socket on the outside.

As Virus said, you haven't got much chance of stuffing a marine battery inside an ammo case. Being metal and conductive isn't an issue unless you're an ass and don't bolt anything down - if it's going to be moved around, everything should be secure inside.

Your best bet is to find two or more smaller deep-cycle traction batteries, which can be positioned in the box with greater flexibility. Get sealed ones or ventilate the box well as you really, really, don't want hydrogen building up inside - when lead-acids are charged or heavily discharged, each cell vents small amounts of hydrogen.

No lead acid battery likes being completely discharged, so make sure your inverter has a low voltage cut-off to prevent this. Most decent ones shut down at 11.1 volts to make sure you can start your car again. It's a good idea to put a fuse directly after the batteries so you don't burn things if something goes wrong - and as Virus suggested, put a switch in the DC line before the inverter so it doesn't drain the battery slowly when not in use.


Thats exactly the important info I was looking for. The first paragraph I got. The next 3 were the good ones

[13579]

There's no way in hell you're going to fit a 12 volt marine battery into a .50 BMG Ammo can or even a 20mm Grenade can for that matter.

As for making a portable 120 V AC power source, buy a deep cycle 12 volt battery, and an inverter that fits your needs. I'd then rig it to where one DPDT missile switch controlled the circuit from the batterey to the inverter. From there I would build a custom box out of non conductive material such as wood and have the outlets exposed, but covered by an external outlet cover required by code on houses.

Of course the entire thing will weigh greater than 50 pounds, but if you really want to that's what I would do.

This man knows what he's talking about. 12 volt marine batteries are HUGE, I'm sure you want a 12 volt car battery.

Even then, I'd try to find a gellcell battery, not a lead-acid car battery.

[MunkeyQ]

This man knows what he's talking about. 12 volt marine batteries are HUGE, I'm sure you want a 12 volt car battery.

Even then, I'd try to find a gellcell battery, not a lead-acid car battery.
Car batteries will die very quickly indeed if you deep cycle them repeatedly. They're not designed to be discharged past 70% - the plates will sulphate over and become very fragile if you bring it into deep discharge.

Gelcell batteries can come in both standby and deep cycle varieties. The same goes really - get a deep cycle version or it'll die sooner than you expect with deep cycling.

And Virus isn't a man. ;)

[13579]

Car batteries will die very quickly indeed if you deep cycle them repeatedly. They're not designed to be discharged past 70% - the plates will sulphate over and become very fragile if you bring it into deep discharge.

Gelcell batteries can come in both standby and deep cycle varieties. The same goes really - get a deep cycle version or it'll die sooner than you expect with deep cycling.

And Virus isn't a man. ;)

Indeed, the only problem with Gelcells I'm aware of is that they take some kind of special charger (According to my dad).

And shoot, sorry about that Virus. I actually wasn't sure for a moment, so I guessed. *Notes in mind*

[asilentbob]

I'm still working on this type of project... I might have posted this here before... but I can't remember... It might have been back at Totse... or another forum. Or it may have been someone else... Really can't remember...

I have:
*a .50 cal "SAW" (fat) ammo can
*Spray painted white.
*drilled holes in one side and installed one of those all weather power outlet covers with foam and wide temperature range silicone sealant. Its just a hole for running wires in and out of should I need to use the battery in less than ideal weather.
*Added some spray on rubber stuff to the bottom for grip along with some fabric mesh stuff to give an even grippier texture. As advice, clean the inside and outside of the can very well first, then sand off the coating on the bottom of the box, spray a layer of the rubber on, add fabric mesh, spray again, let dry, and repeat spraying as you see fit, THEN painter tape the area off and spray paint the rest of the box. You MUST use painters tape, masking tape will stick to spray paint and/or spray on rubber and tear it off when you try to remove it fucking everything up.
*12v 33Ah absorbed glass mat (AGM) sealed deep cycle battery Werker brand (overpriced)
*Cut slab of wood in the bottom of the case to keep the battery from sliding around, however this does nothing in the case of the box flipping over. The battery is rugged, but heavy and could crush the electronics in the box. At some point I'll probably add some sort of battery retaining bolt lattice.
*Watt's Up meter http://www.powerwerx.com/product.asp?ProdID=3809&CtgID=3575 (dig around you can find cheaper after shipping on ebay sometimes)
*200W cheapo inverter. I'm looking to power small things, and a small inverter was the main concern with space at a premium. (400W surge, unfortunately not sinusoidal output, replaceable fuse, low voltage cutoff lower than I would like)
*30A Anderson Power Pole connectors used most of the time, and added to cig outlet adapter, misc types of electrical connectors, etc so that it can easily be used with a few other standards.
*I have a AC adapter hooked up to the battery at all times that keeps it maintained for long term storage, float charger ish. However at some point I'd like to get a 2 or 3 stage proper battery charger for it, mount it in the box, and have a weather proofed cord outside the box that would coil up and stay put on the side of the box. Kinda hard to describe.
*At some point I might add a provision so that hooking up jumper cables to it is easier if I happen to need it to try to jump start a car, which wouldn't be ideal since it isn't really designed for it, but it should still have enough cranking amps assuming the host cars battery isn't completely dead.
*Originally had a solar charge controller and small solar panel hooked up in the box to try to use that to keep it topped up, turns out that the panel doesn't give enough voltage for the charge controller, so it wont work properly.

Some pics:
(Not entirely sure how the forum software will handle these in IMG tags)
http://i41.tinypic.com/u33wl.jpg
-The grip on the bottom.
http://i39.tinypic.com/35aq17a.jpg
-Overhead view with solar charge controller and panel that used to be attached. Obviously the wire should be routed in such a way as to make it stay out of the way.
http://i44.tinypic.com/e6dhq8.jpg
-Watt's Up meter showing current voltage, amp draw, and watt draw, and amp-hours passed through the meter, note that the position the amp-hours reading is at is cycled through watt-hours, peak voltage, peak amps, and/or other crap that I can't remember and haven't had a need for quite yet.
http://i43.tinypic.com/23j4g2p.jpg
-Powerpoles and solar panel closeup
http://i44.tinypic.com/6h26hl.jpg
-Weather resistant fuse junctions are your friend
http://i42.tinypic.com/2hg8rqb.jpg
-Inverter. I haven't found a good way to mount it in the box yet, it has a small fan for cooling inside it and I might have to make some sort of custom plastic mount that won't interfere too much with the air flow while directing the cables where the need to go, etc.
http://i44.tinypic.com/2mgm2vo.jpg
-The space where the inverter would go. Theres also about an inch of space along the side of the battery. I really wish I could have put the inverter there, but I couldn't find a thin enough and cheap enough inverter at the time. They were all just slightly too thick or not powerful enough.

If your going to attempt this sort of thing, I'd recommend you find a slightly bigger ammo can than a "SAW". Though again it all depends on what your goals are.

[KeepOnTruckin]

yep that is exactly what I remember

[asilentbob]

On the marine battery note... A big marine battery for starting and running all the electronics on the boat would probably be out of the question, yes. However, IIRC smaller separate deep cycle batteries are sometimes used for the trolling motor on fishing boats, this way if you run the battery down you don't have to worry about trouble starting the motor. Not really sure on that though.

On the missile switch note, I have a cheaper one that I got and have been thinking about adding it on, however IIRC its amp rating is a bit low, so this is something you must remember to consider in such a project.

Yup, gell cells generally need some sort of different charger, where-as sealed AGM deep cycle batteries should be just fine on the standard easy to find chargers. I originally wanted to put a lower amp-hour rated Nickel-Iron battery in the case, but thats not going to happen anytime soon, fucking expensive beasts... You have to be sure you understand that with lead-acid batteries, if one is 100Ah rated... your probably not going to get 100Ah out of it every cycle without damaging it... Depending on the use and frequency of use... you might get 80% of that... or more likely about 20-50% of that.

Other options are NiCd or NIMH D cells in series and parallel to get the desired voltage, however charging gets a bit trickier. NiCd would be great for high current applications, and generally D cells are about 5Ah. Energizer, Duracell, and other more mainstream NIMH D cells are around 5Ah too, though you can find 10Ah and higher online. 12Ah is the highest I can remember. With these and the other rechargable cells I'll mention you can discharge them fully. Their states Amp-hour rating is what you can actually expect to get out of them.

Li-ion might be a good choice. IIRC many laptop battery packs are made up of the exact same size and type of cell. I think the charging circuits are in the laptops, don't know how hard it would be to extract one... BUT if you work somewhere where you get alot of junked laptops, I think it would be a VERY cool project. A .50 cal can packed with a ton of those, charge regulator(s), inverter, etc would be able to have a really high Amp-hour density.

Li-Poly flat battery pads and regulator boards could make for really kick ass light very high amp-hour density pack too. I really wish I knew enough electronics to work that stuff out. It would be really expensive, but it would also be very small and light.

LiFePO4 is supposed to be 10x greater cycle life than SLA. You can find 10Ah single cells on ebay and online. 4 of these wired in series makes a 12.8V battery. It would be expensive like other "new" battery chemistry, but pretty damn cool.