Harbor Freight car battery chargers any good?

[eccerr0r]

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]

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

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

[redwire]

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.

[televizora]

Originally Posted by redwire

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.

Originally Posted by eccerr0r

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.

[petehall347]

Originally Posted by caphair

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 .

[caphair]

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

[ron350]

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.

[eccerr0r]

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.

[redwire]

Originally Posted by caphair

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]

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")