Newb beginning first build

SockpuppetSockpuppet Registered Users Posts: 2
I'm looking to build my first Solar generator, but plan to accomplish such in steps. It is important that I have a means of emergency power now, and be able to power more than the 400 watts of my DieHard Platinum Portable Power unit.

Apartment living requires it to be somewhat more compact/portable. As such, it should be capable of being utilized in a camping scenario.

Does anyone have a recommendation upon a specific manufacturer for both a:
1. Deep Cell battery, and
2. Pure Sine Wave inverter, with the capability of a continuous range between 1000 and 1500 watts?

It isn't my plan to run such for long periods of time, but rather the capability to do such, along with the potential of adding capacity with another battery or batteries onto it in parallel. A Pure (or True) Sine Wave inverter is required, given the electronic nature of the medical equipment.

After I accomplish such, I'll ask about solar panels and a charge controller.

Thanks in advance for your help.

Comments

  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Newb beginning first build

    Welcome to the forum.

    You're going to need to define the requirements a little more specifically. For example 1000 to 1500 Watt pure sine inverters: there are lots of good ones. Should it have a built-in AC charger? That changes brands and price points. I'm going to point you to our host's OG inverter section here so you can peruse some of what is available: http://www.solar-electric.com/inverters-controllers-accessories/inverters.html

    Battery brands. There are several good ones, but what exactly you get is going to depend on how much capacity you need in Watt hours, how deep the discharge should be limited, how portable it needs to be, et cetera.

    I would hazard a guess you are looking for back-up/portable power for a CPAC machine. You'd be amazed at how many people need that! If this is not the application, please tell us what is and we should be able to tailor the help a little more precisely.
  • SockpuppetSockpuppet Registered Users Posts: 2
    Re: Newb beginning first build
    Welcome to the forum.

    Thank you, it is appreciated. I'm going to attempt to answer your questions in sections.
    You're going to need to define the requirements a little more specifically. For example 1000 to 1500 Watt pure sine inverters: there are lots of good ones. Should it have a built-in AC charger? That changes brands and price points. I'm going to point you to our host's OG inverter section here so you can peruse some of what is available: http://www.solar-electric.com/inverters-controllers-accessories/inverters.html

    I presume the inverters listed are closer to top of the line quality products, which also translates to a more costly product. I'm not opposed to the additional costs associated with a better quality product, but also don't wish to overspend for a less expensive product that would be adequate for the task.

    An inverter charger would be a nice feature, but would it be capable of simultaneously charging multiple batteries on household AC?

    I suppose that I can get away with my Portable Battery Charger/Maintainer, to maintain the batteries as required. I'm already pretty anal of charging my two Die Hard battery packs in my cars.
    Battery brands. There are several good ones, but what exactly you get is going to depend on how much capacity you need in Watt hours, how deep the discharge should be limited, how portable it needs to be, et cetera.

    If everything is perfect, I require to be able to potentially operate 700 Watt hours for 4 hours, before the capacity is discharged too low for operation.However life does often happen to present imperfect scenarios, so I wish to have some wiggle room on that number, to perhaps even include some comfort items.

    I can always build a system to be able to move it, but again, an apartment doesn't lend itself to a lot of space. As such, I'd prefer to keep it reasonably compact.
    I would hazard a guess you are looking for back-up/portable power for a CPAC machine. You'd be amazed at how many people need that! If this is not the application, please tell us what is and we should be able to tailor the help a little more precisely.

    CPAC? You must hold the same values I do. LOL.

    I wouldn't be amazed at all. I have too many years working public safety and nursing, witnessing a fair amount of people with sleep apnea.

    Seriously, I wish it were as simple as a CPAP or BiPAP application at roughly 50 Watts per hour. Without going too far, I potentially require to continuously power a ventilator, humidifier, and pulse oximetry; with intermittent operation of suction, nebulizer, CPT vest, and Gastrostomy pump.

    Each has its own internal power supply for a few hours of operation during utility interruption, but as with any device, its potential for failure or subsequent discharge exists.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Newb beginning first build
    Sockpuppet wrote: »
    I presume the inverters listed are closer to top of the line quality products, which also translates to a more costly product. I'm not opposed to the additional costs associated with a better quality product, but also don't wish to overspend for a less expensive product that would be adequate for the task.

    Well they range from the basic and inexpensive Samlex units (about $380 for 1kW 12V) to the more complex inverter-chargers such as the Outback (about $1700 for a 2kW 12V). In between there are some options like the Exeltech line (about $568 for 1kW 12V). Just to give you some idea of the kind of things that are available and what they may cost.
    An inverter charger would be a nice feature, but would it be capable of simultaneously charging multiple batteries on household AC?

    The inverter-chargers are designed to recharge their own battery banks, whatever that may be, when solar is not available but an AC source is. The value here is that their chargers are designed to work with many different ranges of deep cycle battery so they can be programmed for 'ideal' Voltage and time. Standard stand-alone AC chargers aren't really up to the job, so some life expectancy is sacrificed. The down side is that they are bigger, heavier, and more expensive. The OB is an inverter-charger, the Samlex and Exeltech are not.
    If everything is perfect, I require to be able to potentially operate 700 Watt hours for 4 hours, before the capacity is discharged too low for operation.However life does often happen to present imperfect scenarios, so I wish to have some wiggle room on that number, to perhaps even include some comfort items.

    Okay now we're talking real numbers. 700 Watts for 4 hours is a 2800 Watt hours AC. As a minimum requirement, that's actually pretty big. As in shift up to a 24 Volt system, and then you need 275 Amp hours minimum to meet that requirement at 50% DOD (which leaves almost no room for error). It's actually more power than my entire cabin uses in a day, including running a refrigerator and water pumps. This is looking portable only in terms of "do you have a large truck"? Even skipping the inverter-charger and going with the lightweight LiFePo (not all that easy to work with nor cheap) batteries this is substantial. Especially once you add PV (about 850 Watts).
    I can always build a system to be able to move it, but again, an apartment doesn't lend itself to a lot of space. As such, I'd prefer to keep it reasonably compact.

    See above. Compact is not going to be a major feature when you have to store up that much energy.
    CPAC? You must hold the same values I do. LOL.

    I wouldn't be amazed at all. I have too many years working public safety and nursing, witnessing a fair amount of people with sleep apnea.

    Seriously, I wish it were as simple as a CPAP or BiPAP application at roughly 50 Watts per hour. Without going too far, I potentially require to continuously power a ventilator, humidifier, and pulse oximetry; with intermittent operation of suction, nebulizer, CPT vest, and Gastrostomy pump.

    Each has its own internal power supply for a few hours of operation during utility interruption, but as with any device, its potential for failure or subsequent discharge exists.

    Okay, a bit beyond the CPAC demands then (some of them have much worse than 50 Watt requirement). Sounds like a whole palliative care ward you're trying to maintain. Well I've done some clinic systems for remote places ... but they didn't have to move about.

    I know they probably won't let you run a generator in your apartment but ... It's hard to beat fossil fuels for compact power storage.

    I wish there were a better answer here. How's the budget? LiFePo is more compact than standard batteries with a slightly wider usage range and more resistance to partial state of charge conditions, but approximately 3X the price of standard lead-acid batteries and somewhat more complex to set up and run. They are not for the faint of heart or beginners really.
  • BB.BB. Super Moderators, Administrators Posts: 29,489 admin
    Re: Newb beginning first build

    And to calrify:

    700 Watt*Hours for 4 hours is not the same as 700 Watts for 4 hours (4x more energy).

    I.e.,

    700 WH load / 4 hours = 175 Watt load for 4 hours

    vs

    700 Watt average load * 4 hours = 2,800 WH of stored energy (per Marc's/Cariboocoot's answer).

    For off grid power/stored energy--Conservation and energy minimization is your friend here. Using a Kill-a-Watt type meter to measure each 120 VAC load is a good start.

    Just to give you an idea of how many lead acid batteries you need to supply 2,800 WH per day reliably... This is for an emergency backup up power system, assuming 50% discharge (24 hour period/1 day of use/backup power):

    2,800 WH * 1/0.85 inverter eff * 1 day of stored power * 1/0.50 maximum discharge * 1/24 volt battery bus = 275 AH @ 24 volt battery bank

    Four of these 6 volt @ ~305 AH batteries in series would meet the above estimates:

    PVX-3050T (~$418 each, need 4x) each battery weighs ~91 lbs.

    Or, if you use a Honda eu2000i genst ($1,000 and ~50 lbs) plus a 1/2 gallon of gasoline worth of stored energy (really, would need about 1 gallon of gasoline per every 4-9+ hours of operation).

    Apartments without access to some place to store/run a genset--Very difficult to have any appreciable amount of stored electricity.

    If you have a serious power outage--Having some sort of backup location (friend's home, small R/V trailer+genset+solar+etc.) is really the only safe (and sane) backup solution for critical applications.

    Obviously, if you only needed 700 WH per day (vs 2,800 WH per day) of stored energy--The system would be 1/4 the size and cost (or the larger system would last ~4x as many days).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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