Harbor Freight car battery chargers any good?

[eccerr0r]

Re: Harbor Freight car battery chargers any good?

All lead acid batteries need equalization but you can't on AGM. What do you do when that AGM needs equalization?

Throw it away. :-(

(BTW equalization == "balancing")

[redwire]

Re: Harbor Freight car battery chargers any good?

Seems to be working ok so far. Checked this morning and the display is green and displaying 13v

After removing the charger the voltage on the battery with a dvm reads 13.12v is that normal right after a charge? Not used to seeing anything greater than 12.7v

It's normal for a lead-acid battery to have a "surface charge" which reads as slightly high terminal-voltage right after charging. It will drop down to around 12.8V at 100% state-of-charge.


The Harbor Freight 63350 charging voltages are all look too low There's no evidence it does the top-up to >14.4VDC, it does not do an equalization charge (flooded types need that) and a float voltage of 13.0V is way too low which is a problem.
This means it's charging the batteries to say 80% but doing nothing about sulphate build-up.
If you float a car battery at 13.0-13.2V it has a short life because of sulphate build-up and lack of equalization charge. Most people won't notice.
If you don't believe me, look at car battery datasheets, charging info. I have collected Exide, Trojan, US Battery, Panasonic, Magnavolt, Victron, Powersonic charging voltages. They are largely the same amongst the different chemistries such as lead-calcium, antimony, AGM etc.
Flooded PbCa is charge to 14.7V, float at 13.8V, equalize at 14.7-16.2V 1-3hrs every month. Value depends if deep-cycle, marine, starting etc. A good boil.
AGM/VRLA/Gel is charge to 14.4V, float at 13.5V, strictly no equalization unless really old and beat up.

[eccerr0r]

Re: Harbor Freight car battery chargers any good?

absorption phase = on a multiphase charger, the battery has reached terminal charging voltage, but still taking in charge slowly. Usually higher than 80% charged.
CA = Cranking amps. A fairly useless metric, but it's related to battery specific power, but nothing directly about capacity.
CCA = Cold crank amps, a metric also related to specific power, but when the battery is cold. Useful metric, but still doesn't tell anything directly about capacity.
RC = Reserve Capacity, which indeed is a metric of capacity.

If you take RC and divide by 2, it's very, very roughly the ampere*hour rating of the battery which then you can calculate how long a battery will take to charge from empty.

Due to the exact chemistry of the specific batteries, voltage can be slightly higher and lower. Flooded batteries tend to have a slightly lower voltage than AGM. In any case you do need to wait for an hour or after disconnecting to take a voltage reading to know exactly what's going on, it's OK to be at 13V, and AGM packs are frequently significantly above 13V when fully charged.

[ron350]

Re: Harbor Freight car battery chargers any good?

Caphair here is a picture showing what the Harbor Freight 63350 charger looks like in maintenance mode.

My 63350 goes through three stages.

When you hook it up the back light will flash red for a minutes.
Then the back light will stay red with the voltage numbers changing and the bars on the battery symbol going up and down.
When the charger decides that the battery is charged the battery symbol will show full (five bars) and the back light will turn green.

[caphair]

Re: Harbor Freight car battery chargers any good?

Seems to be working ok so far. Checked this morning and the display is green and displaying 13v

After removing the charger the voltage on the battery with a dvm reads 13.12v is that normal right after a charge? Not used to seeing anything greater than 12.7v

[petehall347]

Re: Harbor Freight car battery chargers any good?

How long would it generally take to fully charge a 12.3v battery at 2/4amps? The listing this charger claims? I picked one up and it's been sitting at 13.8v now for about 4 hours

i sometimes leave them on for a week to get them back up . others are on constantly and in use .

[televizora]

Re: Harbor Freight car battery chargers any good?

One review had blown capacitors, another said it's actually 12V 2A and 6V 4A so around 25W. The "4A" label is misleading.
That's the problem - a low battery will overload any charger and chinese stuff is already pushing parts too hard and poof.

Here is equivalent Lidl charger
https://www.youtube.com/watch?v=YsFQ_75nCYQ
And SMPS has good efficiency and usually small SMPS are able to provide good/adequate currents.

depends on the battery of course.
Though at 2A it could take a day to charge some of the bigger batteries. However at 13.8V it should be about full, though it may still be in absorption phase.

Last time my battery was depleted by leakage currents in my car, with this kind of charger it took me almost a day to charge it up to acceptable level. 72Ah...
3Ax8=24Ah. 3Ax16=48Ah. At this point the battery was sufficiently charged, so the car can start without any problems. The rest of the capacity the car alternator restored after driving out of the town with 80-90km/h.
But I love to buy batteries at least 20% bigger in capacity than what the car really requires and it is recommended. If the manual says at least 48Ah, I will install 62Ah. If it says 52Ah or more, I will directly put 72Ah. The price difference between the capacities is not that large and usually putting the biggest battery that fits guarantees you that when the battery becomes worn off and it's capacity drops, it will not drop so quickly below the point, where the battery is still adequate to start the car.
Some people say that this overloads the alternator. But the simple logic shows that if you consume 10Ah from 48Ah battery and 10Ah from 72Ah battery, the alternator in both cases will need to restore exactly 10Ah. But in the first case it is about 1/5 of the capacity and in the latter 1/7 of the capacity. And during the winter this is significant. And if you deplete your battery significantly, you have to charge it with external charger anyway, unless you plan to drive long distances soon. Or there is some kind of electronics/wiring malfunction in your car. That eats battery capacity. And this usually is radio, alarm, electronics not going to stand by mode or plain things like forgotten lights.
So, if you have battery problems too often, check the alternator - if it's charging adequately, the voltage it provides. Check for anything that drains it - radio not turning off and what the stand by consumption is by using mustimeter in amp meter mode. If everything checks out and it's fine, then it is time to replace the battery.

[redwire]

Re: Harbor Freight car battery chargers any good?

Make sure the mode is correct for either Gel/AGM or flooded/standard.
Example BCI Group 35 battery is 45-60Ah and 12.3V is roughly 60% state-of-charge, so at least 14hrs to fully charge.

It should climb up to 14.4V before backing down to float. I think the display backlight is red until it thinks it's charged the battery, then it goes green.

[caphair]

Re: Harbor Freight car battery chargers any good?

What’s absorption phase? The battery is probably around 500 CCA

Just want to make sure the charger isn’t faulty or anything

[eccerr0r]

Re: Harbor Freight car battery chargers any good?

depends on the battery of course.

Though at 2A it could take a day to charge some of the bigger batteries. However at 13.8V it should be about full, though it may still be in absorption phase.

[caphair]

Re: Harbor Freight car battery chargers any good?

How long would it generally take to fully charge a 12.3v battery at 2/4amps? The listing this charger claims? I picked one up and it’s been sitting at 13.8v now for about 4 hours

[eccerr0r]

Re: Harbor Freight car battery chargers any good?

Are people using AGM car batteries or flooded? Seems these chargers need to know what type else they will over/undercharge them?

hmm... the battery that got destroyed, I added about 600mL (!!!) water into it and it started taking a charge. I wonder what it's self discharge, CCA, and RC are now. Probably still needs to be replaced.

[redwire]

Re: Harbor Freight car battery chargers any good?

One review had blown capacitors, another said it's actually 12V 2A and 6V 4A so around 25W. The "4A" label is misleading.
That's the problem - a low battery will overload any charger and chinese stuff is already pushing parts too hard and poof.

[petehall347]

Re: Harbor Freight car battery chargers any good?

i have a few of these sort of chargers and 2 are in constant use .never had a problem with any of them . only ones i had a problem with are the 3 that i was given to fix and i made them worse . and it cost me nearly the price of a new charger in parts .yes my own fault but my heart isnt in fixing things for more than they cost for a new one .

[redwire]

Re: Harbor Freight car battery chargers any good?

The super cheap Harbor Freight/Cen-Tech 12V battery float charger #42292/022-0192/61911/63161/62813 is almost always a piece of junk. It's a LM7805 jacked up to 13.5V linear regulator, with parts from the bowels of guangdong.

OP's Harbor Freight Viking 63350 I haven't seen a full teardown, reviews are just by dough heads. Many are complaints about them failing.
It looks wrong going to a (12.5V standard) 13.0V float with AGM? https://www.youtube.com/watch?v=ygG1cwYfj7U&t=337s so I am not optimistic. Seems to be some problems with it entering maintenance mode.

I'm going to make yet another car battery charger on my own because of the junk out there. In the pandemic lockdowns, need proper float charging at least a 2-stage (bulk/float). I have a 15V 4A PSU coming and just have to write some firmware.
My old $7 Aliexpress 12V 2A unit runs so hot but it works nice has a 14.6V then drops to 13.8V setpoint.

[televizora]

Re: Harbor Freight car battery chargers any good?

"Smart" chargers get confused and either restart the bulk charge/top up/equalize routine again, while other chargers do nothing and just stay in the float state. Both are wrong - the first will overcharge and the battery uses water, the second method the battery sulfates.

You can't expect 15EUR charger to be very smart. They fulfil they function, but have some shortcomings or flaws. The situations you mentioned are complex and lets be honest, most of the people need charger to occasionally charge their batteries, not use them in complex scenarios.
You want 15EUR charger to fulfil the function of device which is at least several magnitudes more expensive.
The MCU inside the charger gets confused because the device was never meant to be used in such environments and scenarios.

The HFT float charger killed one of my batteries, so one strike against hft chargers. Not the same item however. Really need to get a better charger or mod an existing one... Couldn't crack open the float charger without destroying it unfortunately.

No screws? Usually the two parts of the case are joined together using snake head screws. If you don't have such screwdriver, you can make one from a flat screwdriver by cutting a slot in it. Using angle grinder or hack saw.

[eccerr0r]

Re: Harbor Freight car battery chargers any good?

The HFT float charger killed one of my batteries, so one strike against hft chargers. Not the same item however. Really need to get a better charger or mod an existing one... Couldn't crack open the float charger without destroying it unfortunately.

[redwire]

Re: Harbor Freight car battery chargers any good?

I just returned an Energizer 2A car battery 6V/12V maintainer charger - 5 yr warranty and the electronics were good quality but the firmware is crap.

It would look for several volts before turning on the output relay. So a really discharged battery esp. 6V it would not do anything. So I used a lab power supply to fool that.
Then, it would send a full current pulse and if the voltage went high i.e. 14.4V it would go into ERROR thinking the battery had an open cell or something. Instead of restoration.

Problem is these microprocessor chargers are too complicated to actually work properly. Pic is an 8 stage charger!

Example, it's charged your car battery and it's sitting at 13.8VDC float and life is good. Then the parked car does a canister purge, draws a few amps for 30 seconds so the voltage sags. Or the RV fridge runs etc. The case of a load appearing for a short time.
"Smart" chargers get confused and either restart the bulk charge/top up/equalize routine again, while other chargers do nothing and just stay in the float state.
Both are wrong - the first will overcharge and the battery uses water, the second method the battery sulfates.

I haven't tried the Harbor Freight chargers, but just know these things can have low quality hardware or firmware. Some Schlumacher chargers are crap and way overcharge, youtube vids about them. They are just cheap chinese builds.

[televizora]

Re: Harbor Freight car battery chargers any good?

Purchased one on sale in 2019 that was an open box (returned ) charger and it would not stop charging. After 48 hours it was charging with 15 volts so I returned it..

If the box was already opened and the charger was returned, don't you think that there might be a reason for this?
You complain that opened and used item was faulty.

I still have/use one of those ancient large transformer chargers...sigh. Wonder if it's worth to mod it to regulate it or stop it from charging once it reaches full voltage...

Of course, it is worth to add circuit which turns off the charging when the battery is already full.
This can be done with thyristor and some other components. And the old transformer chargers do the job, but are heavy and bulky.
Not to mention that they aren't that efficient as SMPS.
Not to mention that they usually don't have any type of protection whatsoever, except some fuses.

[stj]

Re: Harbor Freight car battery chargers any good?

dont forget your free multimeter!