My Deka(Duracell) golf cart battery mfgr. says:
"Charge until change in current <0.10A per Hr./Max Time: 12Hr"
I cannot find a way to program the change in current parameter into the Classis/WBJR setup.
Any suggestions?
Thanks
Phil
Hi pao2,
These batteries appear to be Sealed. It is fairly common for manufacturers of these to sped a rate of change in charge current. Renewable Energy Charge Controllers usually do not have this uncommon charge mode.
What these batteries really want is a very, very long Absorption stage. You could measure this current manually with a very good DMM and an external Shunt. The WBjr is an accurate battery charge current measuring device.
All Switch Mode CCs have a bit of current jitter (a small variation in a short period of time). But, you should be able to get an idea of this very small change in charge current over time.
The one thing is, that the required Absorb time varies with the Depth Of Discharge, so it is possible that every day the required time, ideally, would need to change.
Opinions, Vic
My deka solar ATM's are the same charge parameters. I must say a long absorb cycle is not the safest thing to do.whizbang did helped I. Determining a good EA for absorb termination. Go with the who bang first.you would however have to loom at a few absorb. Y less to determine the most suitable .wbjr is. Pt ideal either for these batteries
OK, have not seen the charge specs for the exact batteries that pao2 has, or the product model number.
I do ASSUME that these are AGMs.
mahendra, you are correct, that an Absorb that is longer than needed, is by definition, too long. And the required time varies, depending upon the Avsorb voltage.
Have ALWAYS used EA to terminate Absorb, but this is for Flooded batteries, where a single EA number works great.
So, will let others, who actually use these exact batteries, whatever the model number, comment on just how to do this. However, this charge requirement from the manufacturer makes this type of battery difficult to use successfully in some RE applications.
A change of 0.1 Amps in one hour is a very slight variation. One might guess that a change in battery temperature in that one-hour interval MIGHT negate this small current change.
Good Luck, Vic
yes that is correct Vic because as i have indicated wbjr has worked well but not ideal in my opinion. because i have noted the ea would change when the temperature changes so i have set my ea to the closest ea with respect to the most regularly seem temperature which is about 28 to 30 degrees Celsius.
I use the same exact same Batteries...It has taken some time to find the perfect Charge Perimeters.
But Here are the settings. I use 12 at 1290 Amp hrs for 12 volt.
Absorb 14.6 Volt 4 hrs
Equalize 15.3 volt -3mv Temp Comp
Battery Status for WBjr 94 % eff 1% temp comp
Ending for 12 batts 12 amps, 2 amps per 2 batt tied for 12 volt
They are not AGM ! These are the GC 215 ah batts
OK Solarvet,
Seems that MOST Golf Cart 6 V batteries ARE Flooded, but there are some Sealed versions -- mostly AGM, I believe.
The Change in Charge Current spec is fairly common for Sealed batts, but seems (to me) to be uncommon for FLAs, where a simple EA value works SO well, AND one can actually MEASURE SGs with a Hydrometer, to determine how the charge parameters set are actually charging the batteries.
So, mostly by implication, seemed that the batts in question might well be sealed.
But guessing by implication with little actual info does not always work well.
For your batteries, the EA value is close to what we use here on similar-sized battery banks.
I do wonder about your temp compensation value for charging voltages (as I read it) of - 3 mV. -5 mV works on the Flooded batts here, although they are a different brand than yours.
YMMV, Thanks, Vic
What I would do is to temporarily set the absorb time for many hours so you can watch the battery
current during absorb. You will see the current drop as the battery sits at absorb and then the
current will appear to stop dropping even though the current may move up and down a little bit.
Note the approximate current that the WB Jr. appears to jump up to during this time.
Let it sit in absorb a little longer. An hour if you want to but if it doesn't drop any lower
in, say, a half hour, you are probably done with this experiment.
Then adjust the ending amps to something slightly higher than that higher current that
you saw the WB Jr. jump up to. Slightly higher meaning a couple or few tenths of an
amp higher so that the WB Jr. current will settle below that amount. It shouldn't be
all ~that~ critical.
Also, note how long it took in absorb to reach this current (approximately) and then
add some time to that, say, maybe an hour if the time it took was only a couple of
hours. Then, either the ending amps can stop the absorb charge or the time which
will be close but you added a cushion of around an hour.
This is what I would do anyway. As the batteries age, the ending amps will most
likely go up and so will need either more time or the ending amps will need to be
a bit higher anyway.
Might be a good place to start.
Quote from: SolarVet on May 27, 2014, 12:19:08 AM
I use the same exact same Batteries...It has taken some time to find the perfect Charge Perimeters.
But Here are the settings. I use 12 at 1290 Amp hrs for 12 volt.
Absorb 14.6 Volt 4 hrs
Equalize 15.3 volt -3mv Temp Comp
Battery Status for WBjr 94 % eff 1% temp comp
Ending for 12 batts 12 amps, 2 amps per 2 batt tied for 12 volt
They are not AGM ! These are the GC 215 ah batts
Many thanks for this information and to all that have provided great feedback.
Solarvet, I failed to mention that i'm using a 48V setup, one string of 8 , wet, batteries.
How would you suggest adjusting your numbers as a start for the 48v string?
With the input of all of you and Bob's 'process' I think i'll muddle thru this.
Unfortunately, I've been running this system for 10 months now without fine tuning so hope that damage to bats is minimal.
I would multiply all charging perimeters X 4 ..Like 14.6 X 4..
I leave the -3mv charging comp ..Because that is Spec By Deka. I had to call them to get specs on charging.
The 48 volt Ending amps I would assume since I am 12 volt you would divide by 4 .
So since like mine was 12 amp i think at 48 volt it would be 3 amps. Since the higher voltage.
Phil,
YES, if you want to duplicate what Solarvet is using for charger voltage settings, you would multiply by four to go from his 12 V values to your 48 V system.
If you want to duplicate SV's EA value, you will need to know his correct 20-hour Capacity, and yours. It appears that SV's EA value is around 1% of C. Think that SV has SIX parallel strings on a 12 V system (12 batteries, as I read it). So SV's C is six times the C of a single string'
If you have a single 48 V string of the exact same battery, then, the EA value would one sixth of what SV is running (if he does have six parallel strings).
All that being said, really, the Acid-Test ... err the Gold-Standard for determining just how well Flooded batteries are being charged is to SIMPLY MEASURE THE SG READINGS OF EACH AND EVERY CELL WITH A HYDROMETER. It IS as simple as that. From this, EA can be determined, and even the correct temperature compensation of charge voltage, as well (if the environment allows one to see reasonable temp swings of the batteries).
Off the soap box for now, Good Luck, Vic
i did almost exactly what boB advised .The same advise was given at an earlier forum thread.but now that i am using ea for absorb termination rather than time thanks to the wbjr.
what boB mentioned about the amp to wbjr changing is very true and it can frustrate you a little if not a lot.so yet you have to take some time and get it right .I would advise to take all loads off too when doing this although it can be done with loads on as well.