Author Topic: ISO Info about 12v car lighter to Recharge a 120v AC Electronic Device. Thanks!  (Read 1221 times)

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Offline RoostaTopic starter

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So, here's the deal...I'm probably over thinking this, but I want to be sure before I make a purchase.Let's begin, shall we?

The Layout. . .
I'm buying Sony Xboom portable Party Speaker Model GTK XB60 to use when I go to and work electronic music festivals. Before I checked out on Amazon, it occured to me that I should check the power source configuration because I need to be able to charge in places that don't have electrical hookups. So obviously I need a speaker I can either recharge/power via a power bank, generator, or my car which is usually parked at my campsite or nearby the camping area. My preference is power banks they're relatively affordable for a decent one. (Anker 10kmAh w/dual usbA quick charge ports and will recharge my JBL Clip & Google Pixel 3XL from 0-100% 3 times each on a single full charge MSRP 69.99) However, it just so happens after tons of research, the one dang speaker I finally choose to buy recharges via 120v AC, 60hz 2 prong wall socket cord. The cord is removable (not fixed to the speaker) & the other end of the power cord that connects to the speaker is (not positive of the variant here, hoping I can get some clarification?) as far as I can tell a C7 female (notched ”figure 8” shape with 2 holes just like an 8) that plugs into the male coupling on the speaker (a recessed housing with 2 round prongs) I'm also confused about the gender on this connection because normally the pronged side is the male but in this scenario the end with the holes slides into a fitted housing but still slides over the prongs . Lol so idk, ANYWAAAAY...
What the ultimate goal here is to find the best method to recharge this large PA style Party Speaker that normally gets charged via a wall socket but instead with the 12v DC outlet in my car, a power bank with USB A ports, or through a small AFFORDABLE NON GAS Powered generator (can't have fuel powered genies at the pretty much every camping music festival I've ever worked because of the noise, pollution and almost guaranteed fire hazard because one or many people who don't know what they're doing do just that burn down a tent City because they didn't know what they were doing).

The Concerns. . .

I think the charging the speaker via the car would fine but be slow going and the car has to be on for hours just wasting fuel (took about 7 hours to recharge the afore mentioned Anker 10kmAh power bank from dead to full via usbA to micro USB in an Anker Fast charge 3A that fits into the 12v socket) I think the GTK XB60 has a 15kmAh battery inside so that's gonna take a looooong time to charge up! If I used a power bank to recharge it I need to find a USB A to C7 charging cord and a new power bank at least as many mAh as the speakers internal battery with probably the fastest recharge capability rating on the market which my bank account is already having nightmares about. And then the quiet gasless generator is probably the best option because they come with multiple charging ports usually with USB A, 2 prong wall sockets, micro USB, etc. They can store a lot of energy (the large powerbank style) or generate there own but the only kind I know about that's not gas powered are solar powered and almost none of them comeWITH a solar panel. All of this by the way is research I've been drowning in for the past month or so and I just want someone to be able to tell me definitively which method I've listed above will work the most efficiently, won't damage the brand new expensive speaker I'm buying by degrading the lifespan of the internal battery, won't cost as much as the damn speaker, and if there's some alternate option I haven't thought about!

The Question. . .

Out of the above methods which is the best option?

If I go the 12v DC car charger route, would trying to find a 12v to C7 (if that's even what that plug end is called) so I can plug the charging cord directly into the speakers 120v AC port? Or would buying a 12v converter or inverter (don't know the real difference between the two, I think converter since I want to convert the car batteries power from DC to the speakers normal AC but hopefully someone can clarify)be better so I can just plug the two prong into the converter/inverter box?

Is there an affordable power bank 15k mAh or larger that could recharge or help to off set how rapidly the speakers battery dies while in use? Again I have to have a way to plug the speaker in to the power bank!

Generators! I would love to have a generator so I could power lights and electronics while camping but they're expensive and most festivals ban them and any flammable fuel source like gas, diesel, kerosene, propane tanks larger than the personal Coleman tanks. They usually allow non-gas powered generators like rechargeable and solar powered but they're even more expensive and all of the ones I found don't come with the solar panel. Combined I've priced then at around $500 dollars to be fully set. . .that's 200 more than the speaker lol. Obviously it's an investment for the future and it could power a lot more than just the speaker but I just can't right now.

Is there anything I've ignorantly mispoken, used the wrong nomenclature, completely don't understand, overlooked, or just plain don't know that you've noticed? If so, please enlighten me! I'm a student of all things until I cease to be, and my father recently passed away so I no longer have access to 75 years of experience and wisdom regarding all things "handy man" that he regularly mentored me in.

Anyway, I think that's it. Below I'll attach photos of the specs for the speaker with accompanying photo of the actual speakers power input ports, and specs on the speakers power cord. I WANT TO STRESS THE FACT THAT I DO NOT WANT SUGGESTIONS THAT WILL DAMAGE THE SPEAKER OR ITS INTERNAL POWERBANK SUBSEQUENTLY DEGRADING THE RECHARGEABILITY AND OVERALL LIFESPAN. NO GAS POWERED GENIES ARE AN OPTION. SOLUTIONS THAT COST MORE THAN $200 ARE NOT VIABLE AT THIS TIME. YOU CAN GIVE ME A GOOD RIBBING ABOUT HOW OVERLY METICULOUS (probably obsessive) IVE BEEN IN MY RESEARCH AND MY GENERAL LACK OF KNOWLEDGE AND UNDERSTANDING OF ALL THINGS ELECTRICAL...BUT ONLY IF YOU HELP ME FIND A WORKING SOLUTION!!

Thanks for the help!
« Last Edit: September 08, 2019, 03:49:22 am by Roosta »
 

Offline MosherIV

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Hi
Welcome to the forum.
You have 2 choices
1. Find a car lighter socket to usb adapter that can output 1A or more (they are fairly common now)
2. Look for something called 'car inverter' They convert 12V to 120V AC, however they do not create true clean AC but more of a square wave. Some mains equipment do not like thus 'modified sine' mains.

If you charge from the car without the engine running, it will run the car battery down.
You may want to top up the car battery with a large solar panel.
 
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Offline Ian.M

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The Sony GTK XB60 Speaker nominally needs 120V to 240V AC, 55W and there is absolutely nothing to suggest that it may be able to accept low voltage DC input.   Its USB connection is for playing media files from USB mass storage devices and/or charging USB devices.  It cannot be used to charge the speaker.  Unless you are willing to hack it to bring the internal battery connections to the back panel, there is no way to charge it direct from DC.

You can probably use an inverter in your car to get 120V AC,  but even at only 55W load, an inverter that's 90% efficient will need over 5A at 12V, (possibly a bit less at 14V in with the engine running), so if you own a smaller vehicle, you'll need to be really careful.  e.g. the manual says it needs 4 hours to charge,  so if you shut it off immediately its charged and unplug the inverter your battery will be down by 20AH.  If the cheap inverter has a high quiescent current consumption and you dont get back to it to disconnect it as soon as the Sony battery is charged, you could easily be down 30AH overnight.  If the battery is in good condition and fully charged and you are driving the next day enough to recharge it, you'll get away with it, but if you don't drive the next day and ýour battery is getting on in years, or you need to charge it a second night, odds are you'll need a jump start to get off the field you are camping in.   OTOH if you drive a big truck with *LOTS* of battery ampere hours or a RV with a separate 'house' battery, you will probably be fine weekending.

The other issue is will it charge properly from the output waveform of a cheap inverter?  I've had various chargers that wouldn't unless you put a 40W or 60W incandescent bulb in parallel with them on the inverter output.  That would double the current consumption and make charging without the vehicle engine running extremely inadvisable.

IMHO it would be worth looking for amplified speakers (or an amp + separate speakers) that will accept 12V power in, then getting a Lead Acid Leisure battery (i.e. a deep cycle one) and a charging kit for it sold for use in small RVs, boats and caravans that will charge it off your vehicle alternator when the engine is running.  The Sony speaker has an internal battery of 2500mAH at a nominal 14.4V, or 36 Joules energy.   Even a crappy little 70AH leisure battery will have about 50AH usable capacity (you never want to run it right into the ground as that kills Lead Acid batteries) at an average of 12.5V which is 625 Joules energy.  That's 17 times more so even if the 12V speaker system is only half as energy efficient as the Sony, you'd still be able to run a week long festival just on one charge. Avoid SLAs and maintenance free batteries as the key to long battery life is to give it a really good gassing charge as soon as possible after you run it low, then top off the cells with distilled water to replace what was lost gassing off.   If you are really skint, a second hand car battery from the scrappy would probably be good for half that, and could keep you going for a three day weekend.  You'd also have readily available 12V for LED lighting, charging USB devices via a vehicle adapter etc.  OTOH the battery will be about twice the weight of the Sony speaker for a 70AH one  so its more heavy kit to hump around the field and venue.   A folding sack trolley is your friend!

Incidentally, when it comes to home comforts, I wouldn't advise running a 12V fridge as they typically average several amps draw, so running one for 24H will need a really big battery.  You are better off freezing down in advance 2L bottles filled with 1.8L of water then squished till its at the top before putting the cap on so they dont burst as they freeze., then putting a layer of them in the bottom of á large well insulated coolbox with a thickish layer of newspaper on top so they don''t freeze your provisions.  You want the total ice volume to be about a third of the coolbox capacity. That's certainly good enough for long weekends.    Fill the bottles with potable water and you can drain off the melt water into a thermos flask every morning for chilled drinking water. 
« Last Edit: September 08, 2019, 10:46:34 am by Ian.M »
 
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Online IanB

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Just to mention, the reason that speaker has a mains plug and charges from the mains is because it is BIG. Not only is it big, but it also has a BIG battery inside it, which is how it can run for up to 14 hours on a charge. So this is a BIG speaker, with a BIG battery, that requires a BIG power source to charge it. Did I mention the whole thing is BIG?

So forget the idea of charging it from piddly little sources like USB power banks or solar panels. It isn't going to be practical at reasonable cost. Little portable power sources won't have enough juice to charge something big that needs a mains plug. In fact, you will notice the speaker has a USB outlet for charging phones and stuff from its internal battery. This speaker is meant to provide its own power that it brings with it.

I don't see an easy way to recharge it unless you can find access to a mains outlet at reasonable intervals. How long will you be away from connected mains supplies between uses?

(Technically, I see that it uses a 14.4 V, 2500 mAh, 32 Wh lithium ion battery as a power source, which is similar to the kind used in power tools. So theoretically they could have designed it to use plug in power tool batteries where you can carry spares. But they didn't do that, so you seem to be stuck with the internal battery.)
« Last Edit: September 08, 2019, 10:46:54 am by IanB »
 
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Online IanB

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The Sony GTK XB60 Speaker nominally needs 120V to 240V AC, 55W...

This specification is weird. Firstly, the manual says it will take about 4 hours to fully recharge the battery, and the battery is 36 Wh capacity, so the charging power should be about 9 W plus losses. Secondly, the manual says it will run for 3-5 hours at maximum volume on battery power, which implies a power consumption of around 7 to 10 W. So where is the rest of the 55 W going when it's plugged into the mains? I guess we could have 10 W for music, 5 W for lights, and 10 W to recharge the battery, which is 25 W or so. Maybe they are just being very conservative.

 
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Offline Ian.M

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You are probably right and the actual consumption charging in standby mode is more likely somewhere around 22W.  I got that number by figuring if it can run four hours 'flat out', its going to take as much again to charge it while running 'flat out' + the 55W must include 10W for its 2A USB socket.  I wouldn't expect its internal charger to be very energy efficient as there is little incentive to make it so.

Also the Sony speaker isn't cheap - you could get an óff-brand 12V 2x50W  Bluetooth capable amplifier, + reasonable speakers + a cheap 70AH leisure battery, + an overnight mains charger for it + a 12V input 2A per output USB power bar + a folding sack trolley to tote it all around on for a similar price.  Later adding solar or wind generator capacity to keep the leisure battery topped off is also simple and easy when the battery is 12V Lead Acid.

Setting up with a proper battery to battery charger cabled to a fitted battery box in the trunk to transport and charge leisure batteries in your car is *NOT* cheap, but one can get away with a cheap plastic battery box strapped down in the rear footwell, and a lead from the lighter socket with a beefy Schottky diode (>10A) and both filaments of a car headlight bulb paralleled (mounted in a proper socket in a vented tin can inside a second can with glasscloth lagging so it isn't a fire risk), in series to prevent reverse current and limit the max charging current (to avoid popping the ligher socket fuse) to charge it.  It will only charge significantly when the engine's running, and may not be worth it if you aren't going to be driving at least one hour each day.

There's also the security issue: The Sony speaker is highly attractive to thieves.  A homebuilt wooden box with a 12V amp, USB charging sockets and an 18Kg leisure battery in it + separate cheap speakers from Goodwill,  is is much less so and is also readily recognisable and difficult to dispose of for drugs money.   Remove any lifting handle or carry strap and padlock the sack trolley  in its folded position so it cant be used and hide it and odds are you could go off for lunch without it growing legs and walking away on its own!
« Last Edit: September 08, 2019, 11:29:40 am by Ian.M »
 
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Offline RoostaTopic starter

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Well, lol, I think that's the fastest and probably the most detailed answer for any question I e ever dropped in a forum. Thanks so much for your time and explanation. Since I posted this I watched a slew of YouTube videos on the ins and outs of power inverters, portable power banks, and gasless genies. I basically gathered just about as much as you're saying in that it's just not practical to recharge without a wall a a mains power source without dropping $500 plus on a yeti or Honda 500wh or higher portable power supply. As far as other high consumption appliances go while camping, the speaker would be the highest consuming. No fridge necessary! I'm a chef and use the dry ice submerged in regular ice with a piece of particle board between it and my food and drink (with reeealllly tight locking deli containers to keep all of the food in so they don't become carbonated.... Except for some fruit cause youver never had a clementines until you've had a carbonated clementine!)
These camping festivals generally allow entry at some point on Thursday (Wednesday if I work the event) through Sunday (Monday if I work) so 3 to 4 full days. That being said, I'm usually at my Basecamp primarily from mid morning (awake with the sun usually but sometimes get a rare op to sleep til about 9am) until around 2pm, into the festival grounds until just before sunset, eat dinner and recoup at camp until around 9 and then head back into the music grounds where I usually stay until the music ends (1am) and depending on how I'm feeling I either head back to camp to party with neighbors or head to the campgrounds parties in vip and rv camping areas. I obviously wouldn't be carrying this speaker around with me but when I'm at camp definitely during the day I would be listening at 50-60% for let's say 6 hrs total per main days and to be on the safe side let's say 3 hrs on arrival day and packout day. I would also like this particular speaker because time and time again DJs do popup sets in the camp grounds as a kind of gift or thanks for the fans and show of community but a lot of times they just can't gather up enough equipment from campers to get a decent Soundsystem going due to the ban gas genies and professional audio equipment but this speaker falls within the parameters for allowable sound equipment because it's classified as "portable rechargeable" and it's one of the only ones that also has an audio in and out jack. But it's no good if I can't recharge it. Sometimes you get lucky and the camp grounds have those big portable road construction lights with their own built in generators to light the portapotty areas and to give ambient lighting to the camp grounds for security purposes but a lot also don't have them. The ones that do in my experience also have 120v power outlets so the grounds crews can plug equipment in if they need to and you will see people huddled around them all hours of the day recharging their phones and such but it's about 50/50 on them being there are not.

To clarify, you're saying that if I did go the car inverter route, is there one you would recommend for my situation? Also, I want to make sure that I'm clear in understanding that the speaker consumes 55w when recharging while the speaker is off or is it less but consumed 55w if I were to be using the speaker while plugged in? Also you said that it could damage the car battery if I don't charge the speaker fully and again remove the speaker immediately after reaching full charge even while the car is idling? The car btw is a 2011 Ford mustang 4.0L v6 with a standard Duralast battery that's pretty new (6 months or so...not sure of the ratings will check and lyk).

Well that's about all I got for you. If you really think it's just not worth the trouble and I should look at other speakers then I definitely will but j think that was about the smallest lowest consumption speaker in it's class that had the audio output and portability that I was looking for. Even the JBL boombox which is hakd the size has a mains power cord. Anyway thanks again for your help!
 

Offline MosherIV

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Quote
I want to make sure that I'm clear in understanding that the speaker consumes 55w when recharging while the speaker is off or is it less but consumed 55w if I were to be using the speaker while plugged in?
No! We are not sure what the 55W means. The sums do not add up to 55W from our assumptions about amplifiers and chargers.
Frankly, we do not know. (At least that is my understanding of what has been posted).

Quote
Also you said that it could damage the car battery if I don't charge the speaker fully and again remove the speaker immediately after reaching full charge even while the car is idling?
No! If you use an inverter to charge from your car, you will serverly run the car battery down. You may not even be able to start your car after 3 days/charges. You should re-charge the car battery by running the car for a 2/3 of hours in between each charge if you want to do this.

It would be more efficient to find speakers that run from DC. Then find battery banks to run the speaker from. LiPo or LiIon give you better energy density than lead acid. You can then take 3/4 of these banks to the weekend. Charge them up before you go. Look at the hobby radio control world (hobbyking though other retails are available) for cheap high energy banks and chargers.

 

Offline Ian.M

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IanB is of the opinion that it will use much less than 55W when charging.  My revised opinion is it will use somewhere around 18 to 22W when charging in standby (or off if it will charge when off).   That's around 2A + the inverter's quiescent current consumption when charging.  If you can get back to it to disconnect it after four hours charging, any reasonable condition vehicle battery that started off well charged should be able to handle 25AH of discharge, so you should be able to get away with charging it three times without running your vehicle.  Maybe a few times more depending on the vehicle battery capacity.  It seems that's a good match to your usage.  OTOH if your vehicle battery is on the way out and you haven''t realised yet, you could easily end up needing a jump start.

However smart load sensing inverters that will run properly on such a low load, + shut off cleanly with a low enough quiescent drain not to risk flattening your battery don't come cheap, don''t come in low wattage rating and usually require installation as most lighter socket wiring is too small for anything except the cheap low wattage inverters. 

We could probably help you design and build a four hour time delay relay with under-voltage cutout to put between the lighter socket and a cheap  inverter so you can start the charging before you head out at 9PM without any risk of it flattening your car battery overnight if you forget to check back to disconnect it before hitting the sack.

Using an inverter to charge it will only damage your car battery if you drain the car battery too far and too often.   20% of a good battery's capacity is nothing to worry about.  It *wont* drain your battery at all if you are driving, but many modern cars barely keep up with their usual electrical loads when idling so idling to charge may not be viable short of changing out your alternator pulley and belt to get more 'grunt' at idle speed.  You'd be better off charging with the engine off then doing a beer or pizza run and keeping the RPM up while driving to put back what it used.

OTOH the suggested rig with a 12V amp and a leisure battery could deliver *LOTS* of sound, and if you build it up with line level 1/4" jack and XLR input and through sockets you could well become the goto guy for sound for popup gigs.  If that falls afoul of the no pro audio gear rule, build it up with a 3.5mm input jack (very domestic) and put the XLR and 1/4" jacks on a small (pocket sized) separate box you can keep hidden till needed, with a 3.5mm to 3.5 mm link cable.

If its only going to sit in your basecamp or be dollied over to the center of the campground for a popup gig, the extra size and weight wont be much inconvenience (provided you have space in your vehicle for it), and you wont have to take it back to your vehicle to charge it each night.  It would also do  proper stereo with enough speaker separation to sound good.

*GOOD* LiPO packs and chargers for them don't come cheap.  Also  the venue's health and safety Nazis may have a downer on very large LiPO packs because of the (small) fire risk.  If money was no object, a LiPO pack based system would be ideal and you could probably get the weight down to around 1/2 of a Lead Acid battery based system.  However the pack voltages don't play well with 12V equipment that doesn't have a wider than usual input voltage range.  e.g. a 4S 14.4V nominal pack will be at around 16V fully charged, dropping to 12V when discharged. A 3S pack statrs off at around 12V and drops to 9V.   As long as all your '12V' equipment can tolerate 16.5V in, the 4S pack is the far better choice.  If not, you need a highly efficient regulator.

One hack that might be worth considering would be to get a used GTK XB60 with a dodgy battery and hack it to connect an external 4S LiPO pack velcroed to the back of it in place of the internal battery.   Two budget packs, and 12V and mains quick chargers for them and you'd have good odds of being able to keep it charged.   
« Last Edit: September 08, 2019, 04:54:49 pm by Ian.M »
 

Offline Ian.M

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Its also worth noting that any vehicle that is also sold in Germany that doesn't have all LED lighting should have at least 25AH of reserve battery capacity that can be used cyclically without short-term damage to the battery.   This is because there is a legal requirement to display parking lights during the hours of darkness if parked on most roads there.   Typically on cars for the German market without dedicated LED parking lights,  the indicator switch can be used to select which side to display sidelights with the ignition off, to halve the overnight current consumption.  As sidelight bulbs are typically 10W and there are about 17 hours of darkness in Berlin in midwinter,  running 2 bulbs overnight will take at least 25AH. 

Of course if the US market spec. has a smaller battery, or the German spec battery is getting really old, you can't count on the extra capacity. 

When replacing a vehicle battery, I generally get the largest, highest CCA battery that will fit the tray or box and isn't *TOO* much more expensive than the OEM battery as extra capacity can give you an extra couple of years before replacement and vastly increases the odds of not needing a jump start if you leave the lights on while you are at work, or go off and leave it unused for over a month.
 
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Online IDEngineer

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I just did a ton of research on a similar project so I have a few tidbits to offer. Might not be a complete solution but at least it's data for you to stir into the mix.

My son is an internationally ranked drone racing pilot and we travel (fly and/or drive, sometimes internationally) to a lot of races. His aircraft run on 4S/5S/6S LiPo packs and during practice he will burn through a pack every five minutes (two minutes in the air plus a couple minutes between sessions), which means we must have the ability to recharge these packs in real time. We use multichannel LiPo balancing chargers that consume ~100W per battery being charged, so we are quite often drawing 400+ watts to charge four batteries at a time. Availability of AC power is not reliable at many of these venues.

My first thought was a small (~1KW) gas generator, of which there are a few models that would fit into a standard rollaway suitcase; I figured this was an ideal solution because then we'd be totally self-sufficient even at remote events. Alas, the airline industry flatly refuses to carry gasoline engines in luggage, checked or carry-on, even if the engine is brand new and has never seen gasoline. Just a flat NO. (The one exception was during one of the larger hurricanes... a couple of airlines made a temporary exception for people who wanted to bring generators to help, but they required the box to be factory sealed, AND their staff would cut open the box at check in to confirm the unit was brand new without gasoline, AND you couldn't return with it.)

The other option was an AC inverter, as already mentioned in this thread. If we drive, we have our car... and if we fly, we have a rental car... so no matter what, we have a source of 12VDC and the ability to recharge it. I did a bunch of tests on inverters and determined that they really aren't kidding when they sell "pure sine" inverters. Several of our balancing chargers, and my Hakko soldering station, would not run on "standard" inverters but ran fine without complaint on those marketed as "pure sine". By "pure" they mean low-ish distortion, and most of them publish a spec that is generally <=3% THD. I haven't personally analyzed that but some online reviews suggest that number is reasonably accurate - and the "testers" I care about (our chargers and soldering equipment) are happy.

We now have a 1200W inverter that we take to meets. I picked up a cheap set of battery jumper cables from Harbor Freight and attached ring terminals to one end in place of one set of battery clamps, which allows us to connect straight to the battery terminals. We've used this setup on multiple vehicles at multiple events now and it works perfectly. We "batch charge" our packs so we don't have to run the engine 100% of the time; he burns through a few batteries, we start the engine and charge everything, then turn off the engine. We've done a couple of 2-3 day events this way (so the drain on the car is over an extended period of time) and never had any issues with draining the battery too far, failure to start the engine, etc. I did some heavy load tests to push the limits since the car is idling and not running the alternator at high RPM, and it was only as I approached 1KW of load (a big space heater plus chargers) that I saw any effect - and that effect was a drop in voltage coming off the alternator, which got down under 11V. Loads at or below 500W saw no change in input voltage, which means the alternator was able to keep up with the current draw even at idle RPM's.

If I had it to do over again, I'd drop the size of our inverter to ~600W. This would save size and weight, which are important in airline luggage. That said, our 1200W unit is under six pounds and the cables only add another pound or so. It's a pretty sweet solution.

Most "cigarette lighter" outlets on cars these days are rated for 10A and fused for 15A, so you should be able to draw ~120W that way and not have to mess with jumper cables at all. If your load really is 55W or less as has been suggested in this thread, you should be able to do that via the cigarette lighter and a 200-400W pure sine inverter that costs around $100. (Our 1200W unit cost under $200 shipped to our door via Amazon.)

Second possibility: A fuel-burning generator. Yes, I know you said those are frowned upon by many of your venues, but consider this:


https://www.ryobitools.com/outdoor/products/details/900-watt-propane-inverter-generator

Your original post suggested that "personal Coleman propane tanks" might be acceptable. This little generator runs on exactly that! You screw a little propane bottle right into it and away you go. It also comes with an adapter for standard BBQ tanks, and there are kits to recharge the small tanks from the large ones, so this approach would give you a ton of options and flexibiliity. This Ryobi lists for $300 but I've seen folks online say it goes on sale for under $200 occasionally, so with some prudent searching you could make this quite affordable. The Ryobi isn't the only "mini propane bottle" generator I've seen, either, so look around.

There's two options for you to consider. Hope this helps!
« Last Edit: September 08, 2019, 03:18:08 pm by IDEngineer »
 
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Offline james_s

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What sort of vehicle are we talking about? It's very common in RVs and boats to have separate starting and house batteries, the latter is used to power accessories and they are isolated so that you cannot drain the starting battery by running other things. Depending on the type of vehicle and the sort of locations you use, you could conceivably mount 100W or more solar panels on the roof and generate enough power to charge the speaker and run a small fridge without having to run the engine constantly. When more power is needed, idling the engine to charge the batteries does not burn a great deal of fuel and most car engines are fairly quiet.
 


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