Pro-Logix battery charger is awesome.

[chefwong]

WRC -

If you're still following this thread...what's a good rule of thumb for a AGM if it's being used as a main only, daily driver to put a charger on it to top-equalize it off. Assuming the alt. already is giving the battery a long absorption charge....just not at the ideal voltage of 14.7

One of my Oddy's....manuf in May of this year....just became a nice paperweight. Long story short, it was my dads car. I did not get a chance to visit him until 3 weeks since it occured to wrench on the car. Long story short, turned out to be a bad negative cable, in which the alt. was not charging it, he ran the car till he needed a tow one day....and I got to wrench on it, about 3 weeks later. Battery was reading 4 volts , and in between various methods of doing a restore on the battery, no dice on recovering. There goes $350.......

Anyhow, got me thinking on batteries as a whole.....and what would be considered good practice on equalizing batteries on daily drivers with AGM style construction batteries.

Granted, some of these newer cars won't even charge the battery till full brim, but that is a different discussion to be had.

 

[wrcsixeight]

'Equalizing' is not a charge procedure recommended for AGM batteries.

Lifeline AGM batteries, which are intended as Deep cycle AGM batteries and are likely unheard of in most of the automotive world, and in my opinion make the best Deep cycle AGM batteries, have both a 'reconditioning' procedure as well as a 'recovery' procedure, and both of the charging parameters are well above and outside the maximums listed by other AGM battery manufacturers.

http://www.lifelinebatteries.com/manual.pdf

Lifelines 'conditioning' procedure is similar to a flooded battery's equalizing procedure. Their deep discharge recovery procedure recommends extreme voltages.

Both will cause the vents to open and release some gas. people tend to think this is instant death for an AGM. It is not.

If an AGM is used as a starting battery only, and on a modern vehicle which does not sit unused for weeks on end, One can pretty much just leave it to the vehicles charging system to care for it.

If one cycles their AGM below 95% state of charge regularly, then the vehicles ability to hold absorption voltage as long as required, really comes into play in battery longevity.

A modern vehicle sitting for 3 weeks undriven/unstarted/idled constitutes a deeply cycled battery, and such a battery's charge requirements, if an AGM, are different than a flooded battery. The AGM depleted to 50% can easily suck everything an alternator can make, and do so for longer than a flooded battery.

While AGMs can accept huge currents when depleted and can recharge faster than their flooded counterparts( if extra charging current is available), getting that last 20% takes a long time no matter the charging source. That last 5% can take as long as 80% to 95%, and 50 to 80% can take half the time of either if the initial amps are available.

The trick to fully charging an AGM, or even making an estimate as to state of charge, is done by applying a charging source which shoots for the manufacturer recommended absorption voltage, and having an Ammeter to see how much current it accepts when absorption voltage is reached at the battery terminals.

Lifeline dictates 0.5amps per 100AH of battery capacity at 14.4volts at 77f.

Battery voltage means very little unless fully charged rested open circuit voltage is determined beforehand, and AGMS can really hold their surface charge for a long long time, especially in cold weather.

So the proclamation 'I saw 12.8 volts so my battery is fully charged'

Is inaccurate in the extreme, especially on an AGM.

So top charging an AGM is wise. They are really less tolerant of partial state of charge cycling, compared to flooded deep cycle batteries.

To top charge, apply a grid powered charging source capable of applying the manufacturer recommended absorption voltage until amps required to hold that voltage taper to 0.5% of capacity.

It is not easy to get an automatic charging source to seek absorption voltage when the battery has been alternator recharged recently. One might need to trick the charger by reducing battery voltage by the lighting and restarting the charger.

I use a 40 amp adjustable voltage power supply as a battery charger. I have a wattmeter on the output, and a separate shunted battery monitor, which has been a wonderful learning tool.

My Northstar AGM loves a high amp recharge from the most depleted state.

So with an AGM, goose the voltage upto 14.4v or so. Do amps quickly taper to 0.5% of capacity? If so then the battery was fully charged or very close to it.

If amps only taper to 2% of capacity in a few minutes, then it might take another hour or even 2 hours held at absorption voltage until it tapers to 0.5%.

Since AGM batteries are 2 to 3x as expensive as their flooded counterparts, it makes sense to make sure they can indeed get to a true 100% State of charge as often as possible, and very few grid powered charging sources, can do this automatically, especially since AGM manufacturer recommendations as to ideal charging parameters, vary so widely.

A blinking green light means nothing.

Amps flowing at absorption voltage mean everything.

I've seen my AGM take 10 hours for amps to taper from 2 amps to 0.4 amps at 14.4v, and I've seen it take only 45 minutes.

Most automatic chargers hold absorption voltage via a time based algorithm, not via amperage.

I'd love to be able to put my power supply and my amp gauge on an AGM battery fresh off the automatic charging source that is the topic of this thread. I bet most batteries would need absorption voltage held for another hour or 2 or 4 before amps taper to 0.5% of capacity

 

[chefwong]

Originally Posted By: wrcsixeight
'Equalizing' is not a charge procedure recommended for AGM batteries.


If one cycles their AGM below 95% state of charge regularly, then the vehicles ability to hold absorption voltage as long as required, really comes into play in battery longevity.



WRC, I used the wrong word in my OP. I meant for a AGM for a daily driver, should one hook a charger to: keep the AGM fully absorbed/top off as much as possible.

LOL on the latter quote. ie, one service interval from one manu. has the techs changing out the OE battery after every 2 factory oil service visits, due to the turbos keeping the car running, and the batteries getting a shallow cycle charge over long term. The same manuf. also stops charging the battery if it's 80% full, only really charging via the alt. during decel....for this EPA game chasing #'s...

 

[wrcsixeight]

Yes, fully charge the AGM, keep it fully charged, and it will last a long time.

This is true of any lead acid battery chemistry, but AGMs seem to be more petulant in this demand that they achieve 100% regularly.

Manufacturers Aiming for 80% SOC only is simply them disregarding battery life chasing the EPA numbers

 

[chefwong]

Horses for courses, this thread with your posts, WRC has been a good gulp of 12V Wiki for me.

Out of curiousity, I'm going to give Ctek and Noco a call tomorrow just to understand in clarity more in depth about their charge profile. Ctek spells alot of it out. I've called Noco in the past and while they don't publish #'s in a PDF manual, they will give you the info over the phone. I don't get it though. Noco think it's some secret magic sauce -trade secret on taking a standard 3 stage profile and they have some magic in their chargers.

 

[wrcsixeight]

Ask them how long their absorption voltage is programmed to be held, or if it is an amperage based threshold which must be crossed to trigger float voltage

I almost pulled the trigger on a 25 amp Ctek a few years back.

I am glad I did not. My adjustable voltage power supply was less expensive, has 15 more amps, and gives me the fine control to do what I want, on any lead acid battery I am likely to ever own at any temperature.

I started out with a cheapo adjustable voltage power supply, and even modified it with better ventilation and a ten turn pot, but this power supply had no self protections built in.

Rated for only 350 watts, it released its magic smoke 17 minutes into providing 538 watts. As long as I kept it under about 450 watts it would have been fine, but this required lots of fiddling with the voltage to keep the amps to 36 or under. It would start buzzing over 36 amps.

When I got sick of fiddling the voltage pot to keep it under 36 amps, I decided to sacrifice it to science, and time how long it took before the magic smoke escaped, and the next day ordered the Meanwell RSP-500-15 which has constant current limiting on overload.

A depleted battery is an overload.

My Meanwell now has 2 extra fans ( quiet ones) on the lid and extra finned heatsinks adhered to the casing to dissipate the heat from the transistors which use the casing as a heatsink.

The Meanwell provided fan now only comes on after about 15 minutes at 40 amps output, and shuts off at ~34 amps at 85f ambient. Before modification with fans and heatsinks the Meanwell fan cycled on and off at 6 amps output.

 

[kb27]

Originally Posted By: wrcsixeight
Ask them how long their absorption voltage is programmed to be held, or if it is an amperage based threshold which must be crossed to trigger float voltage

I almost pulled the trigger on a 25 amp Ctek a few years back.

I am glad I did not. My adjustable voltage power supply was less expensive, has 15 more amps, and gives me the fine control to do what I want, on any lead acid battery I am likely to ever own at any temperature.

I started out with a cheapo adjustable voltage power supply, and even modified it with better ventilation and a ten turn pot, but this power supply had no self protections built in.

Rated for only 350 watts, it released its magic smoke 17 minutes into providing 538 watts. As long as I kept it under about 450 watts it would have been fine, but this required lots of fiddling with the voltage to keep the amps to 36 or under. It would start buzzing over 36 amps.

When I got sick of fiddling the voltage pot to keep it under 36 amps, I decided to sacrifice it to science, and time how long it took before the magic smoke escaped, and the next day ordered the Meanwell RSP-500-15 which has constant current limiting on overload.

A depleted battery is an overload.

My Meanwell now has 2 extra fans ( quiet ones) on the lid and extra finned heatsinks adhered to the casing to dissipate the heat from the transistors which use the casing as a heatsink.

The Meanwell provided fan now only comes on after about 15 minutes at 40 amps output, and shuts off at ~34 amps at 85f ambient. Before modification with fans and heatsinks the Meanwell fan cycled on and off at 6 amps output.


I had a Ctek and extreme X charger. They both died not so long ago.

I replaced with a cheap adjustable power supply
http://www.aliexpress.com/item/CPS-6005-...2245745614.html
This can be controlled by limiting current, as well as voltage.

I also have a Meanwell, but it seems to be charging weird.
At the start, it would struggle to put out amps (going on and off), until quite some time when the preset voltage is reached, then the amps would start flowing.
This is observed from the wattmeter attached to the output.

 

[wrcsixeight]

Meanwell makes many power supplies.

Many of them employ different methods on overload to self protect.

When battery charging, one want the models which do constant current limiting on overload, not hiccup or rollback, which will do the behavior you describe as a depleted battery can accept huge charging currents.

My 500 watt unit maxes out at ~600 watts, but it will hold 600 watts forever, unless it overheats. I've added extra heatsinks and fan to both prevent this occurrence, and to add to its ultimate lifespan.
Also to keep the internal fan from coming on, which is very loud.

 

[chefwong]

Off topic or on topic...but at the end of the day, I do like the Cteks/Nocos in terms of user ~usability~ whereas the latter may require more ~involvement~. In my world, it's more to keep the garage queens batteries in check , and the extra toy that I don't take out often.


With that said, it is important IMO for anyone with any smart charger to know what the charge profile is.
Don't press the button and as long as it's flashing, assume it's okay to the respective battery you are charging on

ie: Ctek proudly publishes it in the manual, and it does what it's say (aka, I've watched my meters)

Noco only publishes rough voltages and amps at given steps but NOT the complete profile. I've had both my DC volt and amp meter on it watching what it does. For example, there is this new feature in their charger which they call a ~boost jump mode~. It basically puts out 5 AMPS more than their rated charge specs for 5 Minutes. On my 2600, this would be 30 Amps at 14.4 voltage. HOWEVER, this voltage is not constant. They add in the *desulphate* profile by adding some 16.3 v pulses as well. Granted these higher voltages are just pulses,
I'm not 100% is this is okay/healthy for a AGM battery.

I do know in Lifelines manual, 16 is okay...
Not sure how other AGM's fare in respect to it taking a 16V pulse...

 

[chefwong]

WRC -

Did not speak to Ctek, but Noco advised during the post testing/during absorption, they cut to float during their resistence testing.

OT, or on, but love to pick your brain.
I have a JNC X ForceE Jump Back. This thing is a beast coming in at close to 40lbs. It has 2 batteries in the pack.

I charge this via my 7 amp Ctek on AGM mode - via the clamps on the jump pack. It got me thinking regarding the recent discussion on absorption mode.
Both of the batteries in the pack are wired in parallel.
By using the ~smart charger~, the goal is to keep it topped as possible, bearing AGM's should always remain topped off. Is there a possibility I could possibly be over-absorbing it.....bearing smart charger/parallel battery...

And yes, I have had to re-read your posts sometimes 3X just to digest the info in them. I've considered opening up the pack, adding some direct leads off both batteries....for individual charging, but I don't want to modify the casing...

Anything is still better than the factory wall wart I suppose

 

[Doc8404]

Battery charger owners manual says to connect to positive and then the black wire to the frame. Online, I keep saying that you can connect both cables to the post of the battery. Does it really matter when charging?

https://www.meineke.com/blog/charge-car-battery/

 

[BHopkins]

Originally Posted By: rsylvstr
Battery charger owners manual says to connect to positive and then the black wire to the frame. Online, I keep saying that you can connect both cables to the post of the battery. Does it really matter when charging?

https://www.meineke.com/blog/charge-car-battery/


Hooking up the negative to the car frame, as opposed to hooking it up to the negative battery terminal, is only related to safety. There is no other reason to do so.

Hooking up the negative lead as far away from the battery as possible reduces the risk of igniting hydrogen gasses that may vent from the battery as it is charged. The risk is low, but it can happen. If you think nothing bad ever happens to you, then hook up the negative cable to the battery terminal. As for me, I will continue to hook up the negative cable to a body ground point. In this instance, it's too easy to do the safe thing. So, why not.

 

[henni]

Also, if battery is NOT connected to car, as is the case of a a couple backup batteries we always keep connected to a CTEK charger -- you will not have a "body ground point".

We use these units