battery charging help please.

[snake21]

hi friends,i have a 12v 100ah/10h deep cyce battery.these sets of values are written on it

cyclic use : 14.5-14.9
stanby use : 13.5-13.80
max initial current : 30a

can someone tell me what are those above readings for and what is the maximum voltage for the battery.

thanks

[ghurd]

Cyclic use is when the battery is used hard, then recharged fast, and used hard.

Standby use is a battery waiting on float charge to be used, when it may not be used for months at a time, such as a computer UPS.

Max initial current is the most amps that it should be charged with.
I believe it is also the most amps it should steadily supply to a load.

G-

[snake21]

thanks for the reply

if the stanby use is between 14.5v-14.9v,then i need to set my dump controller to dump power over 14.9v.

does the stanby use mean that the battery need to be charget to that voltage?

what i understood is that the battery peak voltage should be 14.9v and dump loads will be activated when the voltage get over 14.9v?

[ghurd]

No.  14.5V to 14.9V is too high.  It would be OK for a few minutes, but regulating to that high of a voltage will ruin it.

Set it at 14.4V at the most.  Even if it is a flooded battery.

If it is a sealed battery, set it at 13.8V.  Maybe 13.9V at the most.

[snake21]

my battery is sealed type.its good that you told me about the maximum voltage on time.

i will need to re callibrate the dump load controller to 13.8-13.9 now.

why is it that for flooded,it is 14.4 max voltage an for sealed it is 13.8?

thanks

[DamonHD]

Because if you 'boil' the water out of a 'sealed' battery there is no way to put it back and the battery is permanently degraded.

For non-sealed batteries a little 'boiling' during equalisation is helpful.

Rgds

Damon

[snake21]

does sealed batteries need to be equalized.

[DamonHD]

Sealed *cannot* be equalised to the best of my understanding.

(But someone correct me please if I am wrong!)

Rgds

Damon

[dnix71]

Damon, I have a similar problem. One of the powered pallet jacks at work has 4 sealed golf cart batteries (24v setup), but the built-in charger only takes it to 25.3v
I checked today after a full day charging and each battery was 6.3 +/- very little. They all seem to have the same charge, but are not fully charged.

That lift never seems properly charged. It's only a year old. The battery gauge drops like a stone as soon as you use it. The cover comes off easy. Could I hook up a 12v car charger and equalize two at a time? What final voltage should it be 2 x 6v? I can trickle charge, I have a charger with a 2 amp setting.

[bob g]

i would charge them at 14.2 vdc (across a pair at a time) over night, at 2amps, then let them rest and recheck
i would be looking for about 6.7vdc on an agm battery

it may take several days to get them back up again, i had a pair that took a week of on/off/on again charging to gradually
get them back up to par.

that 25.3 vdc charger is just not going to get the job done, and probably will end up wasting your batteries.
a pallet jack gets worked hard and put away wet, and as such can take a higher rate of charge, that is if it isn't a gell cell
which takes a different regime which i will defer to others on, however i bet 25.3 is not even enough for floating a gell cell.

bob g

[DamonHD]

My Morningstar MPPT floats my 12V gel at ~13.7V, so I'd expect double that for 24V.

Rgds

Damon

[zap]

There are a lot of people out there that completely freak out whenever you mention sla and equalizing in the same sentence... or storing a battery on concrete... or recharging alkaline batteries... etc.

The problem with equalization stems mostly from their definition of equalizing and what maybe should be referred to as conditioning instead.

Damon, I have a similar problem. One of the powered pallet jacks at work has 4 sealed golf cart batteries (24v setup), but the built-in charger only takes it to 25.3v
I checked today after a full day charging and each battery was 6.3 +/- very little. They all seem to have the same charge, but are not fully charged.

That lift never seems properly charged. It's only a year old. The battery gauge drops like a stone as soon as you use it. The cover comes off easy. Could I hook up a 12v car charger and equalize two at a time? What final voltage should it be 2 x 6v? I can trickle charge, I have a charger with a 2 amp setting.

dinx71, the bottom line ... find the specs on the batteries although it sounds like the charger is more at fault than the batteries.
If those batteries have been under charged for a year they may have permanently lost capacity.

There's more than one manufacturer of sealed batteries out there that recommend equalizing their batteries...
Concord (Lifeline VRLA): 8 hours @ 15.5v
Dynasty: 24 hours @ 14.4v
etc.

... find the specs.

[DamonHD]

Zap, thanks, that's interesting.

But how is the lost water problem dealt with?  Catalytic caps or something similar?

Rgds

Damon

[zap]

But how is the lost water problem dealt with?  Catalytic caps or something similar?

Exactly!

The manufacture knows what pressure their sealing system can withstand and also knows the capacity of their catalyst recombinant system.
As long as all those limits are met, there is no loss of water.

They all use different systems for sealing and recombination(in vrla), and battery chemistry's  hence the different voltages and times.

I can't find the pdf for my PowerSafe manufactured in July/1996 but I think it referred to a equalization charge that required a strict adherence to temperature levels to keep the valves from opening.

[DanG]

I lend this insight I picked up a bunch of years ago - concord and dynasty both are probably designed around their warranties (by lawyers) using hybrid tricks borrowing from AGM and Gel and FLA batteries.

Excess & thinner electrolyte, increased plate gap, plate chemistry all help protect their profit structure. Remember they sell to anyone coming through the door and must've been burned severely by folks tossing their first SLA lines into circuits that were designed long before SLAs were available to the general population.

Their dealer networks likes contact with the customers to up-sell  - look at the distributor lists, its 95% chain retail battery-only shops.

[dnix71]

Yeah, it's the charger. I took two car chargers to work and boosted the voltage to 6.8 / 6.9 per battery and let them sit. They held 26.1+ as a group. That's what my 24v bicycle battery pack (also agm's) holds. Regular flooded batteries seem to drop lower.

Those batteries have a 170AH rating at 3 hour discharge. That's rough. But I guess it's realistic if you use them in a powered lift and recharge at lunch time and again overnight.

I'm going to let the bldg manager know the charger needs adjusting/repair.

[mjby]

Small system here :

4 Enersys (Yuasa )  UPS sealed VLRA batteries , manufactured 2003 (bought used  in 2005, reportedly used minimally.)  Originally 135 amp hour, connected in parallel.  Approx 400 watts solar charging them in Wisconsin.  System put into place in 2005. I do not equalize the batteries. Float charge 13.6 volt.   Use the trimetric 2020 to monitor  this system and a Solar Boost 50 MPPT charge controller. Rarely discharge to < 80%. System has worked well over the years.

I disconnected the 4 batteries for 12 hours to check the charges.

1) 11.89V
2) 12.91 V
3) 12.89 V
4) 12.90 V

They are in a battery box and each battery weighs about 100 lb (ouch!) Hard to move around. So have not changes their positions.

Obviously #1 is the weak link.  My questions are: Should I remove # 1 completely from my set up and just use the other 3?  With the voltage discrepancy, should I try to fix # 1)  to put back into use? If so, how should I proceed to charge this one?  Thanks all, I learn so much from all you experts.  mjby

[dnix71]

If you are using a 12v system, then the weak battery is just dead weight dragging down the rest.

Sell it for scrap or hold it for the core charge when you replace it.

[Bruce S]

I agree with dnix71, remove the 11V battery from the system so it does not drag the rest down.
It may be recoverable, since it weighs so much.
IF you have a single stand alone battery charger, put in on this one battery, set it on trickle charge for 24hrs let it sit off charge for a day and see if it comes back up and stays in the 13.x range.
IF it does, then maybe try a good deep charge along with a load test to see if you can get it to come back. I would NOT however put this one back into service with the others, unless you know for sure its okay.

Do you have a layout of your wiring scheme that you can post?
You could leave this one off the main bank and use it as a dump load.

Bruce S

[mjby]

Thanks guys (Bruce S and dnix71). I will pull the baddie out of the bank and try to see if I can bring it back. Do you recommend a specific charger to try to bring back? mjby

[Bruce S]

Thanks guys (Bruce S and dnix71). I will pull the baddie out of the bank and try to see if I can bring it back. Do you recommend a specific charger to try to bring back? mjby

Since it is probably toast, I would say one that you already have sould be just fine, make sure it has at least a way to trickle charge automatically or get a good HF cheap-O that only trickle charges. This way if it really is "toast" your not out any further $$$.
Best of luck, worst that could happen is that is becomes trade-in, IF it does come back then you could use it as a dump load and for something like a Oscilatting fan to keep the others cool while summer arrives.

The SG and possible load test will be the deciding factor...

Cheers
Bruce S

[zap]

The SG and possible load test will be the deciding factor...

It's sealed so there's no way to determine SG.

mjby:
If you want to spend a little $ and can spare some of the solar you could get a Morningstar SunGuard SG-4 and let the bad one sit by itself on PWM from the SunGuard for awhile.  It's a little north of $30 if you're a good shopper.

There's no guarantee it will do anything and at 7 years old they're 2 years past the range for standy use (if they're the NPX). Those batteries have already seen a good portion of their life.

If they're the NPX-135 (fromhttp://www.enersysreservepower.com/documents/US-UPS-FL-003_0409.pdf):
cycle use/charge voltage- 14.4-15v
standby use/float voltage- 13.5-13.8v


From Power-Sonic:

What is the difference between cycle use and standby use?

When a battery is being used as a power source on a regular basis and it is being
discharged and subsequently recharged, the battery is said to be in cyclic use. The
determining factor in the life of this battery is the number of charge/discharge cycles that
can be completed. In cyclical applications up to 1,000 charge/discharge cycles can be
expected depending on the average depth of discharge. Standby batteries are meant to act
as an emergency power source where the main power source has failed for some reason.
Consequently standby batteries are kept fully charged so that they can “kick in”
immediately. The batteries remain connected to a trickle charger that will keep the battery
fully charged and ready for use. In standby use the batteries have a design life of up to five
years. Please consult our Technical Manual and product specifications to become aware of
the many factors that effect product life.

[mjby]

Thanks! The battery is a Enersys PHX12-475 UPS battery, to the best of my knowlege, The stdby float voltage specs you of 13.5-13.8V looks like the same for mine. Have been keeping them  at 13.7 volt float. I like your idea of trying to recover it with another charge controller like the Sunguard.  Very much appreciate the input.  mjby