I built my “ham-in-the-box” radio kit that contains my Yaesu FT-8900R for use during emergencies, disasters and anytime there is a “grid-down” situation. And it works like a charm, I love it. Read more about it here < click here to read more >. And as long as there was normal 110 vAC utility power then I was all set because the unit has a MFJ Enterprises Inc. MFJ-4230MV AC power transformer built into it. But what about when the power goes off? Yeah, of course I accounted for the possibility, and this article will address the “power out” situation.
One thing that is a true “unknown” when the power goes out in emergencies and disasters is, 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 I just counted on it staying off…till it came back on. Yes, I am serious. So that led me to the easy answer for alternative power, solar.
I know that for some folks in some areas of the country that solar is a limited choice. And I can appreciate that so I tried to build into the system little redundancy that might help overcome the solar-challenges that people have in some parts of the country and world. Here in the southwest it is not a problem at all so it is a perfect solution for me.
So, as always, let’s define the mission for this alternative power source. The unit must be able to:
“Provide sufficient power to allow the use of the emergency radio kit for at least 40% of any given 24-hour period. During which transmission power usage will be approximately 20% of that time period.”
Requirements & Restrictions:
- Had to be very reliable.
- Had to come from readily replaceable parts.
- Had to have at least levels of redundancy.
- Had to be usable stand-alone or in conjunction with other equipment.
- Should be transferable to other equipment as power source.
- Should be able to charge other electronic components via cigarette lighter and USB ports.
In easier to understand terms: I want my radio to be operational for 6 hours per day, of which about 70 – 80 minutes will be time when I am actually transmitting. That is 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 decent margin of error. So I went with a 100 AH AGM deep cycle battery to allow myself plenty of wiggle room. But that isn’t all.
One of the problems are those times when usage exceeds what your expectations were. 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 is putting all my eggs in one basket; if that battery takes a dump then all of my power is gone. Hence, the whole concept of redundancy, two separate battery banks; 1) the 100 AH battery, 2) the other is 36 AH of AGM battery power (two x 18 AH batteries). The two separate battery banks are not connected.
The large 100 AH battery is an Energizer MAX. And that bad boy is big and heavy. I recharge it using a portable, folding 60w solar panel set-up. The charger controller unit has a “low voltage disconnect” built in. That unit prevents the battery from becoming too discharged and thus damaging the batteries. But I use it to trigger a relay that trips when the batteries become too discharged. And when that relay trips it switches over to the other set of batteries (two 18 AH PowerSonic AGM batteries).
When that switchover is made the larger 100 AH battery can then recharge without any drain on the battery. Once it comes back up to a full charge then the relay kicks again brining the 100 AH battery back online. That also means that the smaller battery bank goes off-line. And to keep those two 18 AH batteries charged up I have another dual 60w solar panel set-up.
But it doesn’t end there. Remember that the Ham-In-The-Box has a PWRgate built into it? Yup, that is the unit that switches between AC power and battery back-up. That makes it nice if the regular 120 vAC utility power goes out it switches automatically over to battery back-up. Sweet, eh? But there is a bonus to the PWRgate…it is also a battery charger when on AC power. So it will maintain the 100 AH main battery anytime AC power is available.
So let’s review the power options for the Ham-In-The-Box and Power-Box combination:
Option #1 – There is normal utility company 120 vAC power available. The Ham-In-The-Box runs off that power and keeps the 100 AH primary battery fully charged. If the AC power goes off the Ham-In-The-Box automatically switches over to the Power-Box.
Option #2 – I can hook up my Honda EU-2000i which then supplies AC power to the Ham-In-The-Box and keeps the 100 AH primary battery fully charged.. If the Honda shuts down the Ham-In-The-Box automatically switches over to the Power-Box.
Option #3 – The Ham-In-The-Box is running off of the primary 100 AH battery in the Power-Box. A dual panel 60w solar system is charging the 100 AH primary battery. Also, a dual panel 60w solar system is charging the two back-up 18 AH batteries. If the primary battery drops below an operational charge (goes dead for operational purposes) the system automatically switches over to the Power-Box back-up batteries.
Option #4 – The Ham-In-The-Box is running off of the Power-Box back-up batteries. A dual panel 60w solar system (or a single 30W panel) is charging those back-up batteries. Another dual panel 60w solar system is charging the 100 AH primary battery bringing it back up to full charge. Once it is up to full charge the Power-Box switches back over to using the primary 100 AH battery. And the Power-Box back-up batteries are then being charged back up to a full charge by the dual panel 60w or single 30W panel solar system.
Option #5 – I can use the Honda EU2000i with the Schumacher SC-10030A battery charger to recharge the 100 AH primary battery (approximately 2 – 3 hours) while the Power-Box back-up batteries are supplying power to the Ham-In-The-Box.
Option #6 – I can use the Honda EU2000i’s 12vDC outlet and plug a cord directly into either solar panel input port on the box and recharge the batteries directly.
I am sure there are more options that would work with this but these are the ones that make the most operational sense to me for an emergency, disaster and “grid-down” situation. But let’s now look at Power-Box and its design and components.
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 all three batteries. And as an added bonus, the storage box has wheels which are extremely important since the batteries are heavy. The storage box is also heavy plastic making it pretty much dirt and watertight.
- Battery #1 – Energizer Max AGM. 100 Ampere Hour, measures 13” x 7” x 9.5” and weighs in at an impressive 60 – 65 lbs (+/-).
- Battery #2 & #3 – Powersonic Battery TY12-18. Each battery is an 18 Ampere Hour, measures 7” x 3” x 6.75” and each weighs 13 pounds.
The combined weight of the batteries alone comes in at 85 – 90 pounds. So far the storage box can handle the weight just fine. Yeah, you are going to have to have help lifting it into the truck or SUV. That’s what friends are for 😉
For recharging the primary 100 AH battery here is the list of components:
- Dual 30w solar panels set-up as a folding, portable kit. (Glowtech System)
- Morningstar SL-20L-12V charge controller.
I went with a system from Discount Solar. The price was $135 and that included shipping. The portable system comes with a charge controller but not the MorningStar SL-20L-12V. The relay disconnect is integral to the system I am building so I simply by-passed the charge controller that came with the system. I did leave the charge controller on the unit for flexibility. I switched over all the internal wire connections to Anderson PowerPoles to be compatible with everything else I have. I will give detailed steps a little later, for now I am just listing the parts.
For recharging the back-up 18 AH batteries here is the list of components:
- 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 paying for the GoalZero name. Don’t fall for it. At the end of this series I will do a Q&A (FAQ) section and provide a tested alternative system that is a whole lot less money. But for now I am going with what I have on-hand. And I did the same thing with this GoalZero set-up and the wiring connection, I switched them all over to Anderson PowerPoles to be compatible with everything else I have. I will give detailed steps a little later, for now I am just listing the parts.
Next article in this series I will begin building the system and share the build along with the pictures.
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