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Reviews For: MFJ-4416 Battery Booster

Category: Power Supplies

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Review Summary For : MFJ-4416 Battery Booster
Reviews: 16MSRP: 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
K3VAT Rating: 2021-12-14
Works great! Real asset for portable operation Time Owned: 6 to 12 months.
I've used the 4416 battery booster on many occasions and actually surprised that it works so well. Specifically, my transceiver operates best at 13.8 to 14.0 vdc (per the manufacturer). My big lead-acid battery (100 Ah) fully charged voltage is around 12.9 vdc. I use the 4416 and adjusted its output voltage under load (via the 4416's adjustable pot) to exactly 14.0 vdc. I can operate at 20-40W many hours on FT8 with no sag at the transceiver voltage input (always 14.0 vdc). Hopefully, the unit will continue to properly function as I'm starting up as a POTA activator soon and will take the 4416 with me. I detected NO noise with the 4416.
K6ELV Rating: 2020-12-09
Causes noise on HF, unreliable. Time Owned: 0 to 3 months.
This device completely failed after a little over 2 months of use. One day my radios wouldn't power on and when I measured the output of this it was only 500-millivolts even though I had 13.2-volts on the input terminals. It would no longer respond to the on/off switch either. $200 down the drain!

While it did work initially and was able to keep my voltage stable around 13.8 volts on transmit, it would cause all kinds of hash and noise spikes all over the HF bands.
I know for sure this device was causing the noise because as soon as I would turn the boost mode off, the noise would disappear.
For a device designed for amateur radio and costing $200 you would think they would include filtering but for some reason MFJ decided to cheap out.

Stay away from MFJ. Don't waste your money on this piece of crap. I will probably never buy an MFJ product ever again.
AA5PR Rating: 2020-08-24
C version unreliable Time Owned: more than 12 months.
Mine functioned for a while but failed in use. MFJ repaired it under warranty. A second failure occurred outside the warrant period, so I fixed it myself. In both cases the failure resulted in an internal short to ground. When I repaired it after the second failure I found that one of the power FETs had a source-drain short. I suspect the first failure was for the same reason.

The low-voltage shutdown circuit seems susceptible to RFI, which I noticed while operating on 2 meters. This manifests as a flickering low-battery light and annoying intermittent audio alert. I do not believe it is supposed to operate this way as an indication of borderline voltage.

It appears you can now buy a more expensive "super robust" booster from MFJ with "heavy duty" transistors. At the time of my review the published schematic shows no substantial change to the power converter portion of the design. It is worth noting that the unit returned to me after repair contained FETs with a lower power dissipation rating than the ones shown in the schematics, so it could be that MFJ is now shipping with the better part. Or not. Buyer beware.

Your money and time might be better spent building power cables with lower resistance. Check this first.

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.