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Harbor Freight VIKING 4 Amp Fully Automatic Microprocessor Controlled Battery Charger/Maintainer

In My Garage

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Joined
Jul 28, 2011
Messages
315
Location
ON
I bought one of them just after they came out a few years ago. I then bought another as a spare. Both were bought when they were on sale...about $25. It seems the regular price on these is like the stock market, all over the place....$37.99 last week, $39.99 today. Go figure!

Charger.jpg

Anyway the charger/maintainer has some great features and when they work as they should, you cannot beat the price.

Unfortunately, the one I use doesn't seem to go into maintenance mode anymore. In fact as the days go on, the battery voltage decreases by about 0.1V per day. Its a good thing the unit has a voltmeter display, otherwise how would you know. I also ran a data recorder on it. I have since the graph below ran it again and it is no different. I will connect my "spare"

Viking 4A Charger-Maintainer Graph - Text.jpg


Having worked with batteries and chargers, evaluating them at the government lab I worked in, these cheaper battery charghers are built to a price point. That would apply to a CTEK and Optimate, both of which I also have, as well as NOCO, Battery Tender, etc. BTW, the one of my CTEKs had the snap-action mode switch fail, a common problem as per YouTube.

BTW, the best battery charger we tested is the Xantrex TrueCharge II, but it is meant for boats and RVs in that it needs a power cable wired to it. No big deal, but some may find that inconvenient.

Earlier this year, I also bought a SOLAR Pro-Logix PL2320 charger/maintainer upon the recommendation of coworkers where I used to work (I'm retired now). A 6V/12V, 20A, 10A and 2A charger that handles AGM, GEL and STD batteries.
 
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laser3kw

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Nov 17, 2012
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7,276
Location
northen IL
I have that same unit. If the battery was dead - dead and below 9.5v, it would not make any attempt to charge. I would use my old "dumb" charger to bring the battery up to 10v and then let it finish it off and do cycle maintenance.
 
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dshop

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Joined
Feb 17, 2012
Messages
113
I have used this exact unit for 4 years now on a 6v Optima battery..not problem one.
I keep it on 3 weeks at a time, then shift it to my 2nd Optima.
Keeps everything charged up...I like it.
 
OP
I

In My Garage

Well-known member
Joined
Jul 28, 2011
Messages
315
Location
ON
I have that same unit. If the battery was dead - dead and below 9.5v, it would not make any attempt to charge.

Not the case as the battery was well above 12.5V when I connected the charger up beginning of November. Furthermore, my data recorder graphs show that it is charging, but then it looks like the charger is on but not charging.

This was the indication today prior to disconnecting the charger. I now have my spare HF charger connected. I'll see how it does.
HF Charger.JPG

And my last graph from the data recorder...
2021-12-05 - Viking Charger.jpg
 
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