I was reading in the Lifeline manual about this. They say to charge at constant current of 5 percent rated 20-hr capacity until 15.6v, then continue 4 more hours. It may reach 18v, be sure your system can do that. So how does one get this constant amperage? With one of these?If it's the right device, I thought it also might be useful for topping off my Fiamms. They prefer 14.1-14.4v, but I bought a PD which puts out 13.6, because I need something plug and forget for when I am tired and befuddled. So, when I wake up in the morning, I could top them with this puppy, yes? And restore them at constant amperage if they get sad?The Fiamms are 132aH, and want 6.6 amps for restoration. 5 amp max adjustable amp supplies are cheaper...is 5a close enough? And just keep turning up the voltage as needed? Would I know more voltage is needed because I set amps at 5 or 6.6, and volts at x, then watched the readout and saw amps drop? Then I would turn volt dial until amps get up to spec again?I am just making sure I've got all this right bec I am not an EE pro like some of youse guys! Plus I thought if it's the right PS, some of you might want one.

Hi Naio,Time to "dance on the needles"? Constant current is what you desire. The one you linked to can do 10 amps.

piano... can you explain to me the difference between a charger that claims constant amp vs contant voltage?

Hi 2oldman,I think you have to dance on the needles to do that.

Is that like angels dancing on the heads of pins? A countable infinity?Or is it just fiddling the voltage as needed to maintain amperage?

With the linked power supply, it will work in either constant current or constant voltage mode, depending on what the load is at any given time. (In other words, the output will go to as high a voltage as it can go without exceeding the voltage setting and without the current exceeding the current setting.) Bear in mind that, for a given load like a battery being charged, voltage and current are not independent of each other; it is only possible to regulate one or the other at any given time. An analogy is a nozzle on a hose that's being fed by a pump. You can adjust the pump so that you have a given pressure in the hose, or a given flow, but you can't set both independently at the same time because the nozzle establishes a certain relation between the pressure and the flow.To maintain, say, a 7.5A charge current, you'd set the constant current knobs for 7.5A and the voltage knobs for the maximum voltage and let the power supply adjust the voltage for you. No knob twiddling or needle watching required, other than to note when the voltage rises to the desired point to start timing.

Adjustable amperage for restoring AGMs? | Good Sam Community

MEXICOWANDERER
Explorer
Jun 04, 2017
Best way raise voltage imcrementally .5 volt. Wait one half hour then raise to next step.
MrWizard
Moderator
Jun 04, 2017
the 8hr/480min discharge rate to 10.5v/1.175per cell
is 14.9 amps

fiamm flx500 data pdf
2oldman
Explorer II
Jun 04, 2017
pianotuna wrote:
2oldman,

That would depend on the battery chemistry and the capacity of the bank. LI have little internal resistance and it doesn't become an issue until 98% SOC.

Lead Acid 85% soc.

AGM 90% soc.
I guess I'll just measure it myself.
time2roll
Nomad
Jun 04, 2017
2oldman wrote:
piano... can you explain to me the difference between a charger that claims constant amp vs contant voltage?
I have a lab quality power supply that will do constant amps. Make the setting and it will change voltage from 0 to 30 to maintain the setting. Only supplies 3 amps but there are larger units available.

I use it to run a model train at Christmas. Goes over the inclines far better than even a more expensive train controller. Maybe DCC system is better but too involved for me.
MEXICOWANDERER
Explorer
Jun 04, 2017
Lifeline in series

18 volts

X

4
red31
Explorer
Jun 04, 2017
2oldman wrote:
Ok. Let's say my battery is sitting at 52 volts (yes I have a 48v system), and a full charge is 58.4. I have a constant amperage charger that supplies 20 amps. What is the voltage delta as it rises? IOW, how many volts over the battery voltage does it need to maintain to "pump" in those amps?

Once the battery gets to 58.4v you'd switch it over to CV till the amps taper to your liking. Or you could start with CV if the amps are not too much for the battery.
Naio
Explorer II
Jun 04, 2017
MrWizard wrote:
Yes Naio
Still loving my batteries
They are still working great

Glad to hear it!! I hope mine will as well :).
Naio
Explorer II
Jun 04, 2017
pianotuna wrote:
2oldman,

That would depend on the battery chemistry and the capacity of the bank. LI have little internal resistance and it doesn't become an issue until 98percent SOC.

Lead Acid 85percent soc.

AGM 90percent soc.

So I should sleep through the FIRST 8 hours?
Naio
Explorer II
Jun 04, 2017
Thanks, Landy!

landyacht318 wrote:

Now as far as doing a constant 5percent of current to 18 volts regularly as some sort of maintenance, rather than a hail mary attempt to revive highly abused batteries.

No, I was NOT thinking to do it as maintenance.

I was just saying that I could maybe use the same power supply, at normal 14.1-14.4 voltage, to top off batteries that prefer that voltage, after first doing the bulk charge with the 13.6 PD.

And then I would also have it if I needed to do restoration in the future.

Well you've read Lifeline's conditioning and restoration procedures.

Odyssey AGM has their own procedure that requires a full discharge under a high load than no less than a 40percent charge rate applied to 14.7 and held until amps taper to near zero.

http://www.odysseybattery.com/documents/ODYSSEY_Battery_Reconditioning_Charge_Procedure.pdf

Oh, interesting! High amps and high-ish voltage. I cannot find a 10 hour rate for my Fiamms online (I may try to call the company). IF it is 80percent of the 20 hour rate, they would want 42.24 amps per battery at the 14.7v.

I don't have anything that would do that, either, currently. The one I linked to might work for my slightly smaller old house battery, though, which is ailing and currently on a 'smart' pulse desulfator I already owned.

Just monitor the battery for excessive temperature when you bring them over their normal absorption voltage. These procedures are not something you just initiate, then decide to go to bed.

I was wondering about that, when the Concorde version says it takes 20 hours. I'd be willing to get up ONCE in the night to check it, but is that enough?

This stuff is on my mind because I have the one ailing battery, and I hope to FINALLY get my Fiamms this week and don't know what shape they will be in. Plus I want to treat them well.
pianotuna
Nomad III
Jun 04, 2017
2oldman,

That would depend on the battery chemistry and the capacity of the bank. LI have little internal resistance and it doesn't become an issue until 98% SOC.

Lead Acid 85% soc.

AGM 90% soc.