Need an electrical solution: TV, Apple TV, M2P batteries, etc.

[7KJT7Y2I]

Solar panel ratings are almost useless in circumstances other than those where they are sized significantly larger than the max load requirement might be.

You need to factor in an inverter/charge controller and battery back.

Looking at your original wish list.........

Mavic 2 battery flown down to 15% SOC will require 44Wh.
Controller at 10% 14Wh.
Iphone 8+ full charge 9Wh

To get your 20,10,10 charge requirement for the above devices (allowing for conversion and charge efficiencies) you will need over 100Ah from a car battery. A car battery of this rating (over 250RC) will be over 40KG in weight and probably a lot larger than your idea of portable. 100Ah of LiFePO4 (4 100Ah cells series connected for 12.8V nom) will weight less than 9Kg and is much smaller than any Lead Acid wet or AGM solution.

I read that wrong...

Can you send a link to the kind of LiFEPO4 you'd recommend for this? I see what you mean -- 40kg is insane

I'm also looking at this generator. As much as I love the battery solution, while inefficient, there's a lot of simplicity with a low-power generator, like this 1000W generator. With that kind of power, I could also throw in my laptop, a few iPhones, and multiple MP2 batteries. It's relatively noisy and all of that, but I carry extra gas cans on my roof rack when I need to (RotoPax). I've been meaning to get a generator for my non-drone work, too. Emergency power, etc.

https://www.amazon.com/Rainier-R2200i-Portable-Inverter-Generator/dp/B07F6PDQP6/ref=sr_1_1_sspa?keywords=gas+generator&qid=1578433423&sr=8-1-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUExRkVBTzlOT0cyOFU1JmVuY3J5cHRlZElkPUEwNDk3MDI3MTFXNFdQODZFSzBEUSZlbmNyeXB0ZWRBZElkPUEwMzE2OTI5MjlYVVFNWURJREtKOCZ3aWRnZXROYW1lPXNwX2F0ZiZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=

 

[WithTheBirds]

I'm actually perfectly happy bringing multiple car batteries. One reason why I wanted that over solar (which I have separately, but enough to charge just a laptop, only 100W total panels) was so I didn't have to rely on sunlight, but also because it's a super robust option, if it's possible. The weight isn't an issue at all. I should have been more clear in the original post: For me, portable means it can fit in the back of an SUV. I want to be able to pull up move the 48" TV in a viewable position, and just share my screen the simplest way: sharing it over AirPlay from an AppleTV. Since I'll be bringing a router and Apple TV, I'm already going to build some kind of enclosure for that (probably just wood/plastics).

So given this, a car battery situation is fine. What kind of inverter do you think I'd need?

It is not just an issue of weight- lead acid starting batteries don't perform well for long when used for remote power. Even discharging half way will dramatically reduce service life and performance. And you really want the potential of a significant quantity of hydrogen gas in your vehicle cabin? No thanks.

The LiFePO4 cells are sealed, they can be discharged 80% or more with no issues, have a very flat voltage discharge curve and can be charged directly from the vehicle alternator. For max charge you will need a boost converter to get slightly higher terminal voltage and a balance charge board for best reliability. You might also need to upgrade your charging system including a higher output alternator.

100Ah cells (and larger) are made by many entities now. I have had no issues with CALB or Winston , I suspect most provide similar performance.

A small generator isn't a bad option either. The Honda's aren't obnoxiously loud like a lot now are, and most were, not that long back. Look for an inverter model.

There is no way around it- a reliable battery setup that suits your stated demands will cost more than you have in the drones, more than a generator, and is a reasonable amount of rooting around to install.

Have you considered a multi battery charger that can top off your batteries while driving? Would be the most economical option and allow for a downsize of the system required to run the TV.

 

[7KJT7Y2I]

It is not just an issue of weight- lead acid starting batteries don't perform well for long when used for remote power. Even discharging half way will dramatically reduce service life and performance. And you really want the potential of a significant quantity of hydrogen gas in your vehicle cabin? No thanks.

The LiFePO4 cells are sealed, they can be discharged 80% or more with no issues, have a very flat voltage discharge curve and can be charged directly from the vehicle alternator. For max charge you will need a boost converter to get slightly higher terminal voltage and a balance charge board for best reliability. You might also need to upgrade your charging system including a higher output alternator.

100Ah cells (and larger) are made by many entities now. I have had no issues with CALB or Winston , I suspect most provide similar performance.

A small generator isn't a bad option either. The Honda's aren't obnoxiously loud like a lot now are, and most were, not that long back. Look for an inverter model.

There is no way around it- a reliable battery setup that suits your stated demands will cost more than you have in the drones, more than a generator, and is a reasonable amount of rooting around to install.

Have you considered a multi battery charger that can top off your batteries while driving? Would be the most economical option and allow for a downsize of the system required to run the TV.

I've come to the conclusion that a generator is my best option. I already have a great gas container solution (RotoPax) so it's easy for me to bring pie tty of gas.

What do you think the minimum generator power (or specs in general) needs to be? I would love it if I could throw in a few laptops into the mix, to charge too. I want to go as cheap as possible since I won't need it for anything other than what I've mentioned so far: Two laptops, drone batts, small/medium flatscreen, router, AppleTV

 

[WithTheBirds]

You are best placed to answer that question. Assuming you proceeded with the excersize of determining the connected load of all devices you plan to have powered on simultaneously.

If the intent is to go cheap forget it. The quality will be remembered long after the price is forgotten.

Look for an inverter type, they are more efficient- often with eco mode.

 

[Electromen]

This Battery Power Supply can feed 3,500 watts at 120 volts for 8 hours. It's not available yet but is coming soon from Milwaukee Tools. It is direct replacement for a generator.

 

[WithTheBirds]

This Battery Power Supply can feed 3,500 watts at 120 volts for 8 hours. It's not available yet but is coming soon from Milwaukee Tools. It is direct replacement for a generator.

Not possible.

Assume you run that unit with two XC406 440 wh battery packs (6Ah @74v each) and a generous allowance for 90% efficiency in the sine wave inverter... On a good day with brand new batteries you will be lucky to get 13.5 minutes (880/3500*.9/60).

 

[Electromen]

Not possible.

Assume you run that unit with two XC406 440 wh battery packs (6Ah @74v each) and a generous allowance for 90% efficiency in the sine wave inverter... On a good day with brand new batteries you will be lucky to get 13.5 minutes (880/3500*.9/60).

You must be very fast with a 15 amp power saw to cut 1,210 - 2x4's - in 13.5 minutes. One every 2/3 of a second.
The product isn't available yet. Time will tell.

 

[WithTheBirds]

You must be very fast with a 15 amp power saw to cut 1,210 - 2x4's - in 13.5 minutes. One every 2/3 of a second.
The product isn't available yet. Time will tell.

We don’t need time to tell... we know we have two 74 volt 6Ah batteries as the available power source. The maximum available power cannot exceed 880 Wh.... it is that simple.

You are assuming also that a 15 amp saw might be fully loaded to max rating cutting a 4 by 2 stud. It isn’t. Nowhere near it in fact. I run 18v drop saws on site and am amazed how many cuts we get out of batteries (saw runs two 6Ah 18 volt packs in parallel. Manufacturer claims 600 cuts (pine studs) for what equates to just under 220 Wh available battery.

It would seem the 1200 cut claim might be easily achievable. 3500W for 8 hours isn’t possible.

 

[7KJT7Y2I]

This Battery Power Supply can feed 3,500 watts at 120 volts for 8 hours. It's not available yet but is coming soon from Milwaukee Tools. It is direct replacement for a generator.

Thank you for the heads-up on this! This is the answer to all of my problems!!!! I can't wait to get one! ?

 

[WithTheBirds]

Thank you for the heads-up on this! This is the answer to all of my problems!!!! I can't wait to get one! ?

I bet you this solution isn't your answer.....

Do your research before you buy.

Unless you are already heavily invested in the Milwaukee pro tool system (have XC406 batteries and a charger) this is a poor value proposition.

The Inverter isn't available on the market yet. When it is you will find that two batteries and the charger alone will run you to around $1300 USD.

You may be able to run an 800W microwave for almost an hour though (based on claims in the marketing literature).

 

[teeroy]

A Honda EU 2000i generator would be the best choice in my opinion. They will run for 8 hrs on a single gallon of fuel in eco mode. They are light, whisper quiet, and have the pure sine wave invertor for your electronics. You can find them gently used for around $6-800.

If you're set on battery power, 2-6v RV or golf cart batteries connected in series to make 12v and a good invertor are the best bang for the buck.

 

[maelstrom]

To get your 20,10,10 charge requirement for the above devices (allowing for conversion and charge efficiencies) you will need over 100Ah from a car battery. A car battery of this rating (over 250RC) will be over 40KG in weight and probably a lot larger than your idea of portable.

Not so. There are plenty of 100Ah+ batteries available around the 20kg mark - see here for an example:

xr-2000

Leoch's XR-2000 is an AGM, dual purpose battery with great durability and superior performance in extreme temperatures. Part of the Xtreme Series.

batterystore.co.uk

For the OP, I’d suggest taking a look at leisure batteries used in caravans and motor homes. Many are 100Ah or more (some more than 300Ah):

The Best Caravan/Motorhome Leisure Batteries

There are many different leisure battery technologies for caravans and motorhomes, learn about the pros and cons of the different types of leisure batteries

www.hortoncommon.co.uk

 

[WithTheBirds]

Not so. There are plenty of 100Ah+ batteries available around the 20kg mark - see here for an example:

xr-2000

Leoch's XR-2000 is an AGM, dual purpose battery with great durability and superior performance in extreme temperatures. Part of the Xtreme Series.

batterystore.co.uk

For the OP, I’d suggest taking a look at leisure batteries used in caravans and motor homes. Many are 100Ah or more (some more than 300Ah):

The Best Caravan/Motorhome Leisure Batteries

There are many different leisure battery technologies for caravans and motorhomes, learn about the pros and cons of the different types of leisure batteries

www.hortoncommon.co.uk

You either misunderstood what I wrote or chose to ignore the context.

Fact is that any battery ordinarily understood to be designed for, or applied to, the purpose of starting a vehicle engine ("car battery") won't supply 100Ah if it is less than 20Kg in weight.

The first link you supplied is for an AGM battery. Might start a petrol engined vehicle but not ideal for the purpose. It is also interesting to note that, according to the published specs, the 100Ah rating might only be realised if the maximum discharge rate is 10A. A serious practical limitation for may use cases.

 

[maelstrom]

You either misunderstood what I wrote or chose to ignore the context.

I'm not an expert on batteries but the other website I linked has an extensive article about leisure batteries which would seem to be ideal for the what the OP requires. The article linked a number of leisure or dual-use batteries which seem to meet his requirements. These batteries are not necessarily designed to produce the output required for starting a vehicle regularly but are used in caravans and motor homes to provide and alternative source of electricity when an external source is not available. If that isn't what the OP is looking for, then perhaps I just misunderstood the problem.

 

[7KJT7Y2I]

I bet you this solution isn't your answer.....

Do your research before you buy.

Unless you are already heavily invested in the Milwaukee pro tool system (have XC406 batteries and a charger) this is a poor value proposition.

The Inverter isn't available on the market yet. When it is you will find that two batteries and the charger alone will run you to around $1300 USD.

You may be able to run an 800W microwave for almost an hour though (based on claims in the marketing literature).

Looks like I got a bit too excited! I see what you mean. Thanks for the advice. I need to go the more economical route, and I'm not already invested in the system.

Running a TV,to allow others to see my live drone video at my vehicle (this aspect is for rescue operations) and charging up a large amount of drone videos, I may still need to go with an actual generator. I thought that a powerful, huge battery could keep me going for a few days, but ultimately nothing beats actual fuel for these purposes. I wish all batteries displayed their actual energy capacity, in amp-hours! In most cases voltage and wattage aren't as big of an issue for me. But it's absolutely critical that I know (of course, under ideal conditions) how many times I can charge X batteries, with a known mAH capacity!

 

[DanMan32]

Actually Whr is more useful as it is constant as you convert between voltages.

IOW a 1000Ahr battery produces 1200Whr at 12v. If you need 120v, the current goes down but the wattage remains the same, not taking into account for conversion losses. So you get 10Ahr at 120v, but still 1200Whr.
Of course you also have to consider maximum capable watts or amps throughout the conversion.

 

[7KJT7Y2I]

Actually Whr is more useful as it is constant as you convert between voltages.

IOW a 1000Ahr battery produces 1200Whr at 12v. If you need 120v, the current goes down but the wattage remains the same, not taking into account for conversion losses. So you get 10Ahr at 120v, but still 1200Whr.
Of course you also have to consider maximum capable watts or amps throughout the conversion.

This is always so confusing. I just wish I knew a clear answer as to "this battery will charge X times with Y device". I wish it were simple!

 

[WithTheBirds]

Actually Whr is more useful as it is constant as you convert between voltages.

IOW a 1000Ahr battery produces 1200Whr at 12v. If you need 120v, the current goes down but the wattage remains the same, not taking into account for conversion losses. So you get 10Ahr at 120v, but still 1200Whr.
Of course you also have to consider maximum capable watts or amps throughout the conversion.

My guess is you have an issue with you maths or typing and you meant to refer to a theoretical 100 Ah battery (not 1000 Ah).

It would seem that the terms "capable watt" or (capable Amp for that matter) whether through a conversion process or otherwise are rarely if ever used in discussing power system design.

Useful considerations for the battery include the Cost, Capacity, C rating, life expectancy (age related), Cycle life and deep discharge performance as probably the most relevant and important.

If we are talking about the suitability of a whole power delivery system knowing current delivery capacity (Amps) at the relevant working voltages is the universal standard for system design. Inverter efficiencies and power factor correction (where applicable) are also important obviously.

 

[DanMan32]

I see what I did. 1000Ahr@12v is 12000Whr, not 1200Whr.
12000Whr@120v would indeed be 100Ahr.

 

[DanMan32]

This is always so confusing. I just wish I knew a clear answer as to "this battery will charge X times with Y device". I wish it were simple!

Well first total the wattage of all your devices and how long you need to power them.

W=V x A
WHr = V x AHr

Whr = W x hrs

So if you want to run 100 watts for 8 hours, you need 800Whrs.
If you're using a 12v battery, you need 66.6Ahr 12v battery (800Whr/12v = 66.6Ahr).