Manager - NA4M
Manager Notes

Reviews For: MFJ-4416 Battery Booster

Category: Power Supplies

eMail Subscription

Registered users are allowed to subscribe to specific review topics and receive eMail notifications when new reviews are posted.
Review Summary For : MFJ-4416 Battery Booster
Reviews: 13MSRP: 139.95
Battery voltage booster
Product is in production
More Info: http://
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
G4AON Rating: 2019-05-19
C version works great Time Owned: 0 to 3 months.
I finally got around to buying a battery booster after several years of grumbling about sagging Voltage and low TX power when portable.

The C version is a significant upgrade to the earlier models and is “keyed” using the keying output from your radio. There is a few mS delay before the inverter builds up the Voltage, which can be overcome by running the inverter all the time on CW. The inverter start time does give a slope to the envelope of the first “dit” sent on CW, although in my opinion it’s not worth worrying about.

Extensive CW transmissions at 100W output barely raised the heat sink or case temperature. The additional heat sinks (over the earlier models) are perhaps overkill, but I’d rather have them than overheating.

The output Voltage is well controlled and doesn’t “sag”. Having both Power Pole connectors and terminal posts on the input and output side, gives plenty of connection options.

I haven’t checked for spurious signals on receive with the inverter running, as it’s easy to wire a key line between the 4416C and a transceiver -plus you have less battery drain on RX by not running the inverter all the time.
PA4M Rating: 2017-06-04
Works good. Time Owned: 6 to 12 months.
Last year I bought a second hand MFJ-4416B battery booster on a ham radio flea market. During the IARU Region 1 fieldday CW contest I was active from my car. In my car I do have an additional 12V/100Ah battery installed. Without the booster the voltage drops below 11 Volts on my TS-480SAT. After a while the voltage becomes too low and the TS-480sat will power cycle.

But with the booster installed I can use my TS-480SAT at full power output all the time. The LCD backlight does not dim anymore on tx.
After 6 hours of non stop contesting at 100Watt I quit. The booster did not run hot and I did not notice any noise on the HF bands. (I was on a very quiet low qrm qth) The booster was switched on all the time, I did not use the RF switching.

I do not own any other MJF products but Iam very satisfied with this battery booster.
W4LCM Rating: 2017-02-15
2 Years, no problems! Time Owned: more than 12 months.
After 2 years of used The MFJ-4416B, is a must for any Icom radio owners or any radio that needs
13.8 volts in portable / field day operations to give you 100 watts.

The Rf sensing is great, allowed you to only used the booster on transmission only, saving you power
from the battery when you are only in received mode.

Simple and easy to install and operated.

This is a great product and I recommended.
AD0AR Rating: 2016-02-11
Better than expected Time Owned: 0 to 3 months.
I have a IC-7000. For us owners of these radios we are all familiar with the power struggle to keep the voltage as near 13.8v as possible.
Continuously adjustable output up to 14.5v ( could go higher)
Low voltage alarm (LOUD- can be bypassed)
Low voltage cutout (can be bypassed)
Input voltage alarm adjustable
RF sense input (not really needed after a simple mod)
Crowbar power protection prevents this thing from putting more than 15v into your radio. It will crowbar with a zener diode/SCR. Result? I feel safer.
This thing can take a 9-13V source and keep it where it needs to be for the radio. I have mine adjusted to 13.83v and it keeps it there rock solid.
RFI? Yes. I get a weak conducted RFI especially on 40M and a little on 60M. They are moving whistles that could kill a QSO.
MFJ was so kind to include a schematic in their online instruction manual that rapidly reduced the reverse engineering time required to see:
1. switching elements used
2. only a ground on a control line is all that is needed to put the unit into boost mode.

So when I got my unit and checked the jumpered configuration, I could not but also notice that the switching elements used are a new, much more efficient mosfet than the one called out in the schematic!!!
Differences? BIG. The old mosfet had a RDS(on) resistance of .15 ohms.
The new mosfet being now used sports a RDS(on) of only .018 ohms.
Much more efficient, less heat generated, less losses in general.
Face it, when hooking this thing up we all have that dichotomy we come to. Do I connect it up to the HF or V/UHF side for the auto boost on TX feature? Obviously more power is consumed on HF, but I'm a purist and I LOVE systems engineering AND I plan to be using it on both V/UHF and HF.
I simply added a control line to connect my 7000 to the 4416b using the hsend and vsend wires.
If you want the gist of this mod email me from the email listed on

Observed losses: This thing consumes around 30mA idle in boost mode. Quite negligible and could probably be reduced even more if the LED is disconnected.
Cons: Only downside observed is that it consumes power even when not in boost as it is constantly monitoring the power rail. It draws around 10mA and will sound a alarm if the connected source drops below the jumper set low voltage. You betcha I will change that ;-)
See you on the ether!
In God we trust, all others we monitor AD0AR

NO0A Rating: 2014-02-26
Great Product Time Owned: 6 to 12 months.
I have owned the "B" version for several months. It supplies power to my Kenwood TS-2000, a Uniden scanner, and my PK-232 on my off grid wind/solar power system. Absolutely no problems. I leave it on all the time and, even though operating late at night with no solar/wind and the battery voltage sometimes drops quite low (below 11V), I always show 13.8 output. There is slight rfi from the unit, but, not objectionable and was expected.
KF5REI Rating: 2013-05-24
Looks like it's finally right Time Owned: 0 to 3 months.
I just finished installing the "B" version of this unit and everything went swimmingly.

I installed this in my pickup and hooked it up to my Kenwood TM-281, which is notoriously finicky when it comes to input voltage and transmitting high power. I set this up with the RF Sense line so it's on bypass until I actually key up. I also removed the old inline engine noise filter I had with the original setup.

The Kenwood runs fine on high power transmit now even with the engine off. There is NO whine coming from the unit or any noise at all. I did a radio check on high power and the other party reported clear signal with no noise or interference whether the engine was running or not, so the unit is definitely acting to filter engine noise as well, which is not surprising considering the technical approach for this unit.

So, older reviews notwithstanding, it looks like MFJ listened to its customers and is putting out a solid unit now.

N5TEN Rating: 2013-05-03
Works Time Owned: 0 to 3 months.
I like the on/off button and all the various options the unit has. I'm using it with my solar battery backup with powergate. The booster keeps the voltage stable, but makes racket when charging up which sounds like a missile flying over my head (into my audio/receiver). It makes this noise for a little while and then calms down.

The best part of this booster is the on/off button and possibility to use it with RF sensing.
N6WBL Rating: 2011-11-22
Works as described Time Owned: 6 to 12 months.
I have the MFJ-4416B (which I believe is the second generation), and I find that it works as advertised. I've used it portable so I could run full power off my gel cells and even a new LiFePo battery which has a better voltage profile almost not needing the boost. I haven't used the RF sensing or voltage sensing functions, just engaged all the time so the rig sees 13.8 volts and stays happy. And per the manual I find it to be over 90% efficient in battery draw over an afternoon of operating. Got it on a pretty good sale, and very happy with the purchase.
N6CZE Rating: 2011-07-29
MfJ-4416B Review Time Owned: more than 12 months.
Mine is the MFJ-4416B revised booster. It works exactly as advertised. My Icom IC-706MkIIG would reduce output when dry camping in a motorhome using the house batteries. At a full charge 12.6v the output was at 100 watts, but dropped as the voltage dropped. Installing the Battery Booster brought the XCVR to a full 100 watts output. No breakdowns, No blown fuses, No problems of any kind. A great product from MFJ.
W7DME Rating: 2010-11-24
Not good! Time Owned: 0 to 3 months.
I purchased this product with the understanding that it would not filter engine or other noise from the D.C. line. I installed it in my truck to work with my IC-7000.

The first thing I noticed was that I was receiving reports of a high pitched whine on my FM transmitted audio that was about 25% of my audio envelope. Hooking up my Tektronics scope to the DC feed, I noted that when the unit was on, it produced about a 1200Khz noise going out to the radio. I did not expect it to filter noise, but never expected it to add to the noise. On SSB, I did not receive any reports, but then other operators may have thought it was just a week carrier on frequency. Then, in a QSO with a Japanese station on 18 MHZ, the unit blew a fuse internally and stopped working. I replaced the internal fuse and it started working again, but I removed it and purchased another brand which has been working well for the last two weeks. No noise generated by that unit, and no failures. It also clean up truck generated noise. I will review that one in another forum.