Is my HF 4 amp charger maintaining?

[LeakySeals]

I have a 19 Cherokee it has been sitting for a few weeks so I put it on a barely used Harbor Freight 4 amp charger to top off the AGM battery. That seemed to go OK. The display showed the battery went from 12.1 to 14.5 for a while. Then dropped down to 12.9. The next day I went out to check on it was still 12.9. Which according to some charts is 100%. Good right? I opened the doors on the Cherokee which has electronic handles that unlock, lights come on, etc. I noticed the display on the HF charger dropped down to 12.5. Still didn’t think anything was wrong so I locked it up and checked on it the next day. Still 12.5 Charging was OK but is that actually maintaining?

So now I’m curious if it’s me or if that charger is not maintaining the battery. Replaced the HF with a 1.5 amp batteryminder 1510 that has been attached to a 2006 Escalade for 3 years. Doesn’t have a display, but I check on it with a voltmeter occasionally to confirm it’s still working. That slowly worked its way up to 14.8 V, then the solid charging light came on, which means charging is completed. The batteryminder stays at 13.6 not 12.9. To compare I did the exact same things electronically. Open the door doors let the lights come on. Shut the doors and then lock it. Then check with a voltmeter. Down to 12.5 just like the HF.

So for a minute, I thought this was all about nothing. But then the light on the batteryminder 1510 started flashing. Voltage slowly increased back to 14.8. I checked an hour later and it was back down to 13.6.

So.. the tiny batteryminder is doing its job and the HF is not maintaining, may not be working correctly at all? If it’s not, should I return it or just buy something else?

 

[JavierH19]

If you can return it I would, If not returnable try to exchange. I'm using this and it's been good after 3-4 years.

https://www.walmart.com/ip/Battery-...["In-store"]}]&classType=VARIANT&from=/search

These two new versions came out.
https://www.walmart.com/ip/Everstar...["In-store"]}]&classType=VARIANT&from=/search

Don't know what makes the marine part special.
https://www.walmart.com/ip/Everstar...["In-store"]}]&classType=VARIANT&from=/search

 

[f355spider]

If it truly has a floating voltage to maintain, then it should float at least around 13.3 or 13.4vt. And preferably at 13.5 to 13.7 for an AGM. Note that some battery maintainers "exercise" the battery by charging it up to 14vt+ then turn off and allow it to drop on its own down to 12.5vts before it starts the charging phase and takes it back up to 14vt+. This can take several days or even weeks before it hits the lower voltage to trigger a charge. You have to read the "Instructions for Use" to see what the algorithm is for that particular battery tender is.

 

[D1dad]

Seems like the battery minder works as it should, unlike the ones I purchased from northern tool. If you want something cheap that works, the motopower 1000ma has a no nonsense algorithm that floats at 13.6. If you want to spend a few buck, the Pulsetech I just bought seems like the real deal and the pl2140 from pro logix has a good algorithm that exercises the battery after a full charge. Although I don’t know if that’s necessary. I have a hard time buying anything more than throw away items from harbor freight. Saw blades, maybe the occasional tool that I’d use once or twice. I don’t know that I’d trust anything electronics, but that’s just me.

 

[D1dad]

My plan is to use the Pulsetech a few times per week to try and keep my new batteries new, as opposed to a maintainer. The pro logix seems useful although I haven’t figured out how. I had it hooked up last night on a battery that’s a few months old and it had the battery charged to 82% even though it had shut off. Honestly the motopower for under $20 has the most consistent float mode. 13.6 all the time and finishes off that extra charge. After I got over the fear of this extremely cheap piece of Chinese manufacturing not frying my ecu and or burning the place down, it’s been great. I can safely say that unless I buy an odyssey I’d probably never invest in an agm for any of my cars. They’re constantly ran down to 50% because the smart charging systems in my cars never reach a voltage that comes close to keeping up. Then the charging sequence takes hour as opposed to a few hrs on my flooded batteries.

 

[f355spider]

My plan is to use the Pulsetech a few times per week to try and keep my new batteries new, as opposed to a maintainer. The pro logix seems useful although I haven’t figured out how. I had it hooked up last night on a battery that’s a few months old and it had the battery charged to 82% even though it had shut off. Honestly the motopower for under $20 has the most consistent float mode. 13.6 all the time and finishes off that extra charge. After I got over the fear of this extremely cheap piece of Chinese manufacturing not frying my ecu and or burning the place down, it’s been great. I can safely say that unless I buy an odyssey I’d probably never invest in an agm for any of my cars. They’re constantly ran down to 50% because the smart charging systems in my cars never reach a voltage that comes close to keeping up. Then the charging sequence takes hour as opposed to a few hrs on my flooded batteries.

Remember the Battery Minder does a constant "pulse" desulfation when floating...it is desulfating like the Pulsetech. All Battery Minder products desulfate.

 

[D1dad]

Remember the Battery Minder does a constant "pulse" desulfation when floating...it is desulfating like the Pulsetech. All Battery Minder products desulfate.

That’s why I haven’t returned them or trash canned them. I figure that just using them as a maintenance item isn’t a bad thing. Plus the temp compensation is to notch. One if floating right now at 13.36 and it’s 50 degrees out. When it was in the teens the other morning it was floating at 13.67. If they’d just not charge a fully charged battery for 18hrs before floating, they’d be great.

 

[nwjones18]

My HF chargers work that way. They will charge and then hold and voltage may be down in the 12's and at some point they cycle back on/off. I've got 6 of the things on various batteries with no issues. I've had 2 die over the years and when they die they just die..

 

[f355spider]

My HF chargers work that way. They will charge and then hold and voltage may be down in the 12's and at some point they cycle back on/off. I've got 6 of the things on various batteries with no issues. I've had 2 die over the years and when they die they just die..

Good to note. So some of these HF maintainers use the "exercise" algorithm for long term battery health. Rather than a float voltage. Nothing wrong with that, just a different approach to solving the problem of maintaining a battery long term.

Regardless, they do not appear to have any sort of standard desulfation process or separate selectable desulfation cycle/mode.

 

[nwjones18]

Good to note. So some of these HF maintainers use the "exercise" algorithm for long term battery health. Rather than a float voltage. Nothing wrong with that, just a different approach to solving the problem of maintaining a battery long term.

Regardless, they do not appear to have any sort of standard desulfation process or separate selectable desulfation cycle/mode.

When you hook one of them up they pulse the voltage as they are charging, will go up and down constantly until they reach charge.

Here's how HF describes the charger:

Microprocessor technology gives this battery charger the power to charge most 6V and 12V batteries including deep-cycle, gel, and AGM batteries. Fully automatic microprocessor control feature adjusts the amperage rate to charge and maintain batteries quickly and safely with one press of a button. High frequency current pulse can be used to recondition car batteries that are weak, sulfated, or deeply drained.

• Microprocessor control adjusts current to match battery type and condition
• High frequency technology is over 20% more efficient and over 50% lighter than conventional charging systems
• Winter mode for specialized battery charging in winter weather conditions
• Large easy-to-read LCD display shows readouts for Charging Mode, Battery Capacity, Battery Voltage, and Charging Faults
• Automatically switches to maintenance mode when battery is charged
• Heavy duty 6 ft. 18 AWG gauge cables

 

[f355spider]

When you hook one of them up they pulse the voltage as they are charging, will go up and down constantly until they reach charge.

Here's how HF describes the charger:

Microprocessor technology gives this battery charger the power to charge most 6V and 12V batteries including deep-cycle, gel, and AGM batteries. Fully automatic microprocessor control feature adjusts the amperage rate to charge and maintain batteries quickly and safely with one press of a button. High frequency current pulse can be used to recondition car batteries that are weak, sulfated, or deeply drained.

• Microprocessor control adjusts current to match battery type and condition
• High frequency technology is over 20% more efficient and over 50% lighter than conventional charging systems
• Winter mode for specialized battery charging in winter weather conditions
• Large easy-to-read LCD display shows readouts for Charging Mode, Battery Capacity, Battery Voltage, and Charging Faults
• Automatically switches to maintenance mode when battery is charged
• Heavy duty 6 ft. 18 AWG gauge cables

Thanks. Is the pulse only present during the charging phase? It sounds like it does not, as the charge to full, then pause until partially depleted, then charge again. But would receive the pulses every time it charges the battery back up to full.

With products like Battery Minder or Granite Digital "Save a Battery" tenders, they run the desulfation continuously during the float.

It would be interesting to see a test at which is better at both preventing sulfation, as well removing and restoring a sulfated battery.

 

[LeakySeals]

Reading the replies I’m wondering if the HF is working normally for what it is, a charger/maintainer only. The 2006 Escalade is in long-term storage so I can test with that.

I put the batteryminder 1510 back on the Escalade where it had been for 3 years. The good news is after being disconnected for a few days, it was less than 1 hour to fully charge and go into maintenance mode. So I’m assuming the 2019 dated battery is in good shape and hold a charge.

14.9 charging
13.6 maintaining

Disconnected the 1510 and connected the HF. Took a little less time to go into maintenance mode.

14.9 charging
12.9 maintaining.

With the HF connected I turned on the lights for a while see what would happen. Digital display dropped to 12.4 and then eventually all the way down to 11.9. There is also an image of a battery on the display, which seemed to move up and down a little bit but I’m not sure if that was the charger doing something or just the change in voltage on the display. I turned off the lights and watched.. the volts slowly went back to 12.5 over the course of an hour. This is when I assumed the HF wasn’t working so this time I waited until this morning to check on it. Was back to 12.9. I don’t know if a battery can recover on its own if it’s in good health. I’m assuming the HF is working. But different.

13.6, 13.7 is what I normally see for a fully charged battery + alternator on a running engine. 12.9 on a non-running engine is considered 100% charge on AGM, not sure about standard lead acid.

Is the difference in the maintenance voltage desulfur mode?

 

[nwjones18]

Reading the replies I’m wondering if the HF is working normally for what it is, a charger/maintainer only. The 2006 Escalade is in long-term storage so I can test with that.

I put the batteryminder 1510 back on the Escalade where it had been for 3 years. The good news is after being disconnected for a few days, it was less than 1 hour to fully charge and go into maintenance mode. So I’m assuming the 2019 dated battery is in good shape and hold a charge.

14.9 charging
13.6 maintaining

Disconnected the 1510 and connected the HF. Took a little less time to go into maintenance mode.

14.9 charging
12.9 maintaining.

With the HF connected I turned on the lights for a while see what would happen. Digital display dropped to 12.4 and then eventually all the way down to 11.9. There is also an image of a battery on the display, which seemed to move up and down a little bit but I’m not sure if that was the charger doing something or just the change in voltage on the display. I turned off the lights and watched.. the volts slowly went back to 12.5 over the course of an hour. This is when I assumed the HF wasn’t working so this time I waited until this morning to check on it. Was back to 12.9. I don’t know if a battery can recover on its own if it’s in good health. I’m assuming the HF is working. But different.

13.6, 13.7 is what I normally see for a fully charged battery + alternator on a running engine. 12.9 on a non-running engine is considered 100% charge on AGM, not sure about standard lead acid.

Is the difference in the maintenance voltage desulfur mode?

Do you have the HF charger in AGM mode?

 

[LeakySeals]

Do you have the HF charger in AGM mode?

I switched the HF to standard mode on the Escalade. AGM on the KL Cherokee. The batteryminder is automatic so I’m not sure what it’s doing. The documentation says the batteryminder it’s not for AGM but turns out in the fine print it will work for some AGM types. I didn’t see any charging voltage difference between the two battery types. If it is doing something different, I can’t tell. It does take longer for the AGM battery to charge and go into maintenance mode. A few hours. More than twice as long.

 

[f355spider]

I switched the HF to standard mode on the Escalade. AGM on the KL Cherokee. The batteryminder is automatic so I’m not sure what it’s doing. The documentation says the batteryminder it’s not for AGM but turns out in the fine print it will work for some AGM types. I didn’t see any charging voltage difference between the two battery types. If it is doing something different, I can’t tell. It does take longer for the AGM battery to charge and go into maintenance mode. A few hours. More than twice as long.

For Battery Minder their standard tenders are fine for both flooded and AGM.
Battery Minder makes specific AGM only and models with an AGM setting, but their AGM modes are specifically optimized to be used on Odyssey, Optima, X2 Power, and other higher performance AGM batteries. For common plate type AGM batteries from Clarios, Interstate, Varta, AC Delco, East Penn, etc, Battery Minder says their normal "flooded battery" setting is recommended.

 

[LeakySeals]

Searching posts it’s mentioned that the float for AGM should be +-13.6?