Quite awhile ago I wrote a multi-part series of articles that laid out my portable power box. I described in detail how I built it and all of the components I used. It was a great project full of practical “how to” moments. And the outcome was a useful piece of prepper equipment for use during emergencies, disasters, or grid down events.
There was a major drawback…the articles were written over an extended period of time with sometimes weeks in between the articles. It did make it hard to follow. I also figured out a few more things, additional & different, along the way.
What I am going to do with this series of articles is edit and update the original articles and post them back-to-back. That should give you the opportunity to understand what I did and why…and then the cohesiveness of information to build one yourself. Let’s get started…
One thing that is a true “unknown” when the power goes out in emergencies and disasters is the question, how long will the power stay off? I tried to get a good feel for it but just couldn’t come up with a valid time estimate. That being the case, for evaluation purposes, I just counted on it staying off…till it came back on.
Yes, lame response but I am serious. So that led me to the easy answer for alternative power, solar. But, is solar power always available?
I know that for some folks in some areas of the country that solar is a dubious choice. And I can appreciate that, so I tried to build into the system a little redundancy that might help overcome the solar-challenges that people have in some parts of the country and world. Here in the southwest solar and plenty of sunshine it is not a problem at all, so solar is a perfect solution for me. But, I grew up in the mid-west where it could be cloudy for weeks at a time.
So, as always, let’s define the mission for this alternative power equipment. The unit must be able to:
“Provide sufficient power to use two mobile radios simultaneously and provide power sufficient to recharge handheld radio batteries, or run low power consumption electrical equipment. And do so independently of regular supplied utility company power.”
Requirements & Restrictions:
- Has to be very reliable.
- Has to come from readily replaceable parts.
- Has to have multiple levels of redundancy.
- Has to run off 120vAC power.
- Has to be auto-switching from AC to DC power when AC power fails.
- Has to keep the battery charged when AC power is available.
- Has to have solar recharging capability.
- Should be able to charge other electronic components via cigarette lighter and USB ports.
- Should be able to “daisy chain” power boxes in series to provide longer DC power availability.
In easier to understand terms: I want my radios to be operational for 6 hours per day, of which about 60 – 90 minutes will be time when I am actually transmitting. That could be pretty aggressive for transmitting time. My Yaesu FT-8900R uses a maximum of 8.5A during transmission. So I figure a 60 AH (ampere hour) rated AGM battery should handle the load with a fairly respectable margin of error. So I went with a 100 AH AGM deep cycle battery to allow myself plenty of wiggle room plus the addition of another mobile radio.
One of the problems are those times when usage exceeds expectations. I really want to make sure that I have enough “reserve” power to handle the radio usage when the demand is at its peak, such as the early stages of a disaster or during an “incident within an incident” occurrence. I could have simply bought a higher rated AH battery but that wasn’t practical. So I went with the ability to run multiple power boxes in series to provide for longer DC power life. But the primary DC power source is a large 100 AH battery which is an Energizer MAX. And that bad boy is big and heavy.
To address the requirement of auto-switching when the unit switches between AC power and battery back-up I had to go with an auto-switch device. That capability makes it nice if the regular 120 vAC utility power goes out, then the power box switches automatically over to the battery. Sweet, eh? But there is a bonus to the PWRgate…it is also a battery charger/maintainer when on AC power. So it will maintain the 100 AH main battery anytime AC power is available. Yes, it does all the fancy monitoring and multi-step charging/maintaining.
So let’s review the power options:
Option #1 – There is normal utility company 120 vAC power available. Everything runs off that power and it keeps the 100 AH battery fully charged and maintained. If the AC power goes off the unit will automatically switches over to the battery. There is zero loss of power during the auto-switching.
Option #2 – I can hook up my Honda EU-2000i which then supplies AC power to the box just as normal utility power would do and keeps the 100 AH primary battery fully charged.. If the Honda shuts down the unit automatically switches over to the battery.
Option #4 – I can use the Honda EU2000i combined with the Schumacher SC-10030A battery charger to recharge the 100 AH primary battery (approximately 2 – 3 hours)if needed.
Option #5 – I can use the Honda EU2000i’s 12vDC outlet and plug a cord directly into the unit. That connection is a direct connection to the battery providing recharging capability.
Let’s go over the actual box first. I chose the Rigid Professional Tool Storage System. This “system” is a group of very sturdy tool boxes designed to work together. The base unit is the Mobile Gear Cart. It is the box that all the other pieces ride on. It measures out at: 22” x 18” x 19”. That is plenty large enough for holding the large Energizer battery. And as an added bonus, the storage box has wheels which is extremely important since the battery is heavy. The storage box is also heavy plastic making it pretty much dirt and watertight.
- The battery – Energizer Max AGM. 100 Ampere Hour, measures 13” x 7” x 9.5” and The weighs in at an impressive 60 – 65 lbs (+/-).
The weight of the battery is significant, approximately 60 pounds. The storage box can handle the weight just fine. The box is actually pretty balanced to moving it around. Yeah, you might have to have help lifting the box into the truck or SUV. That’s what friends are for 😉
Option #1 – I went with a system from Discount Solar Glowtech60 Solar Kit. The price was $135 and that included shipping. The portable system comes with a charge controller.
Option #2 – For another option of solar charging capability:
- Two GoalZero Boulder30 30w solar panels (can be used individually or daisy chained together).
- GoalZero Guardian 12v charge controller.
This is a straight up system purchased from GoalZero a couple of years ago. The equipment is top-notch, high-quality stuff to be sure. Unfortunately you are mostly paying for the GoalZero name but the quality is there for sure.
Next article in this series I will begin building the system and share the steps along with plenty of pictures.
Associated Articles –
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