MFJ-4416B Battery Booster

MFJ-4416B BATTERY VOLTAGE BOOSTERMFJ-4416B battery voltage boosterI really have mixed emotions and opinions on this piece of equipment. In one aspect this is a great piece of equipment that can play an important part of a prepper’s power equipment inventory. On the other hand, it can destroy perfectly good batteries that are expensive to replace. That left me in a tug-of-war on the overall recommendation on this piece of equipment. So I will leave my “buy or no-buy” recommendation till the very end of the article.

First let me describe what this this gem does. The whole concept of this “battery booster’ is to do just that…boost low battery voltage levels to more operational levels for your electronic needs. Specifically, your radio operational needs. Here are the specifics on how it does that.

Your radio has voltage needs for power. My Yeasu FT-8900R needs a little over 10 vDC to continue to operate. MFJ-4416B battery voltage boosterBelow that and it will automatically shut down. That can be a bad thing if you need to stay on the air. So the MFJ-4416B steps in to handle that situation.

The 4416B is designed to take DC voltage as low as 9 vDC and boost it to the level that is required by your equipment. So take the example of my Yaesu FT-8900R, it needs 10+ vDC but the battery is only putting out 9.2vDC. The MJF-4416B boosts that voltage up to a usable level, 11 or 12 vDC (user selectable).

The two most basic elements of this unit are; 1) available voltage going into the unit, and 2) the level of voltage the unit can output. The 4416B can accept voltages as low as 9vDC. It can also be set to output voltages between 11 and 13.8 vDC. If you set the output voltage at 12, any voltage greater than 12v will pass though vs. being stepped-down.

But here is an interesting twist…there is an RF sensor built into the unit. Let me back-track for a minute. Your radio draws a fraction of the power when in receive mode vs. transmit mode. So you really don’t need to “boost” voltage/power when receiving. The RF sensor allows the unit’s regulator to be by-passed unless you are transmitting when the most voltage/power is needed the most. The RF sensor connection is nothing more than a “T” placed inline with your antenna coax and hooked to the 4416B.

There is also a built-in user adjustable feature of a LVD (low voltage disconnect). The LVD option can be set at 9, 10, or 11 volts. I like this added feature. A stand-alone LVD can easily run $50 – $90.

Here is the downside, if you run a SLA AGM battery down to even 11 volts you have damaged the battery and reduced the lifespan of that battery (reduced recharge cycles). If you run down a regular lead acid battery to 10 or 11 volts you are probably OK. You run them down to 9 volts and you’ve just shorted their life considerably.

Here is the upside, if you are running alkaline batteries the 9v input capability (LVD) just gained you a MFJ-4416B battery voltage boostersignificant additional amount of life out of your battery. Who cares how low you run an alkaline battery down to. The alkaline battery only has one life anyways, you might as well squeeze every last minute of operating time out it while you can.

And there is another upside as well, if you are really, really needing the operational time from your radio and you just have to keep it up and running, the booster will allow you to do that. So you will get additional operational time out of your batteries; albeit, you may destroy them in the process. But, it might be worth it.

While doing my research I did find some not-so-complimentary issues with “noise” going out, especially when using the RF sensor. However, those issues were all over 6 years old or more. And from what I can tell it was all with the original version of the 4416 not the 4416B version which is what I tested. I did a quick search and couldn’t find any vendor still selling the original version. Although you might see one come up on eBay, I doubt anything other than the “B” version is being sold.

An interesting side-benefit to using this booster is kind of interesting. Radios generate heat based on incoming voltage among other things. If a radio can operate on 12v it will generally run cooler at 12v vs. 13.8v. With the 4416B you can use your batteries at 12v, the 4416 booster set at 13.8v in conjunction with the RF sensor. So anything 12v or over passes through while in non-transmitting mode. But at 12v your radio is in receive mode at 12v, it is not being automatically being boosted to 13.8v. Well, not being boosted to 13.8v until you hit the PTT key. While transmitting the 4416 will boost to 13.8v to give you maximum output wattage and then return to whatever your battery is putting out (12v or greater). Nice way to keep your radio a bit cooler.

MFJ-4416B-remoteThere is a remote control option available for this battery booster. Sweet little set-up for convenience sake should you choose to go with this battery booster. MFJ-4416BRC gives you full remote control of your MFJ-4416B Super Battery Booster plus it allows you to monitor battery voltage and battery booster output voltage.

You can place the battery booster near your battery or other convenient location close to your radio. The MFJ-4416BRC lets you turn booster and low battery alert on and off. It has boosting and low battery LEDs to let you know what is going on with the booster.

It requires a Cat-5 cable to connect the remote to the battery booster. It measures a compact 5″w x 2″d x 3″h and mounts with 4 screws. I think this is an absolute “must-have” if you are using the booster for your primary rig. Just makes sense to monitor what is going on with your power. If you are using the 4416B to begin with, you obviously have a serious need. Why not be able to monitor exactly what is going on with your batteries and your booster; performance monitoring.

So here is where I would use the MFJ-4416B battery booster:

  1. When my rechargeable batteries wouldn’t be harmed running down to 9, 10 or 11 volts (user selectable).
  2. When I was boosting alkaline batteries and they were throw-a-ways once I was done with them.
  3. If I had to keep my radio up and running, even when battery voltage was running low. This would be an emergency operations type of situation.
  4. I was in procession of a decent supply of 12v rechargeable batteries, car batteries or similar.

Here is where I would not use the MFJ-4416B battery booster:

  1. I was running AGM, SLA batteries that would be harmed by over-discharging them.
  2. I would not use this booster in any other situation or application other than to keep a radio up and running. I can’t think of any other piece of electronic gear that would be worth potentially destroying 12v rechargeable batteries.

I like the product and own it. Obviously, or I wouldn’t be able to do a review on it. But, the usage of a battery booster is limited in scope and focus. Using it in the wrong application can cause you to spend a whole lot of money replacing your AGM, SLA batteries. And in disaster, emergencies and during “grid-down” batteries might be a bit hard to come by.

Technical Information –
  • Battery Booster Width: 7.750 in.
  • Battery Booster Height: 4.000 in.
  • Battery Booster Depth: 2.125 in.
  • Battery Booster Weight: 1.30 lbs.
Sales Pitch (straight from the website) –

Keeps your transceiver operating at full efficiency and performance by eliminating low or marginal voltages in the mobile environment.  MFJ 4416B super battery boosters keep your transceiver operating at full efficiency and performance by eliminating low or marginal voltages in the mobile environment. They accomplish this by boosting input voltages as low as 9 V up to the desired 13.8 V at 25 amps peak with a typical efficiency of close to 90 percent. Even at their compact, lightweight 1.3 lbs., they are designed to be rugged, reliable, and easy to use. The MFJ 4416B super battery boosters include Anderson PowerPole connectors and high-current, 5-way binding posts for both the DC input and regulated output. An internal 30 amp input fuse protects them from excess output current demands. There are also selectable limits on the minimum voltage that can be accepted, protecting you from over-discharging a battery and possibly damaging it. They also include output over-voltage crowbar protection, should regulation be lost. An RF sampling port can be connected to your transceiver’s transmission line with a UHF-T connector, which is sold separately. An additional efficiency enhancement feature is a user-adjustable output voltage control, which lets you set the output voltage anywhere between 12 and 13.8 V. When setting the output at 12 V, input voltages greater than 12 V will pass through, but the efficiency of the regulator is higher, and lower input voltage means that your transceiver will run cooler. They typically save over 30 watts in heat dissipation during transmit, and even 3-4 watts during receive.






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