ea values for deka solar batteries

[mahendra]

ok I just got my whiz bang jr. from ALte store. However as i previously stated in another thread .I have been playing around with various values to determine a suitable ending amps for  my system. My absorb Amps seems to plateau to the 1% mark of the Battery bank amp hrs. But that does not seems to be a good EA value for my batteries,since they are being undercharged. The information given by Deka for their batteries is: "End Condition - Charge until change in current < 0.1A per Hr/Max Time:12hrs" .i do not grasp what they are trying to indicate from this instruction,Can someone please explain?

[boB]

I wonder if maybe they mean...

No more than 0.1 amp-hour change in  12 hour period ?

So, if that were true, basically watch for the amp-hours into the battery to slow WAAAAY down ?

boB

[mahendra]

i was thinking the same but could not see the amps go way down ,so don't know what to really do now and again i say Deka is really miserable with customer service.

[Vic]

Have seen this or a very similar spec in the past.

Believe that this is saying that the change in the charge current is the 0.1 A in ONE HOUR,  with  maximum Absorb time is 12 hours.

HOWEVER,  this current is normally scaled to the AH Capacity of the battery bank.

A spec like this seems relatively useless for batteries charged from RE sources.

Are these batteries Flooded Lead Acid?

How is it that you have determined that the 1% of Ah is undercharging the bank?

It is also possible that Absorption voltage is too low to fully charge the battery with the 1% EA,  and so on.

Thanks,   Vic

[offgridQLD]

I'm happy to do a plot on my system after xmas and share it here.

I have 14.5A as my end amp seating for now 1% of my capacity + 1.5Amps just to make sure it gets under that to trigger. I did have it as 16.5A before the wizbang  a few amps higher to take base idle loads into account. It worked ok befor as long as no one was turning on large loads on for long periods as  then the timer would take over.

Now with the wizbang I am often surprised at how many amps the classic is pumping out when it triggers float say 25A,  doing the calculations it's always spot on 14.5A true charge to the battery. It's just there are loads on the system say fridge doing a defrost + a few idle loads that would have been overlooked before I installed the wbjr shunt.

The good thing is I have noticed a measurable drop in the average daily KW into my battery now I am using the WBJR to trigger float. Its  10% reduction on average. That has to be much healthier on the battery especially over the hot summer.

Kurt

[mahendra]

well i arrived at the 1% of ah from midnite solar forum and naws, and i arrived that it is under charged because my battery voltages keeps dropping from using this EA value as compared to my previous setting

[mahendra]

i have used the recommended voltage threshold for all charging parameters as specified by the manufacturer.They are AGM batteries check Naws they stock these batteries.

[zoneblue]

For FLA, they tend to err on the side of overcharging. As per other thread AGM requires less stirring, and have vent release & catylyst consumption issues.

For EA its better to work out your batterys EA setting yourself, rather than rely on the documentation.

Just watch one absorb cycle, taking readings every 5 minutes, and at the point where the battery current starts to plateau, that is your EA. I go along with Curts tip to add a little to ensure a reliable trip. If your batterys flatline at 1.1 amp, you dont want to set EA to 1.0 amp, else it will never happen, and run through to max time.