customer

Cgarner

I have a customer I have been trying to figure out what is going on with her system.  They have outback batteries and we just went through a long painful experience in getting an answer if their batteries were bad or not.  They are still good.  But I asked for assistance to see if we changed her absorb time from 1 to 2 hours would it make a difference, they are not allowed to give advice.  so the issue is after one hour of batteries being on they shut off.  They are off grid.   They have 9 - 285 watt panels 1 outback flexpower 120 v Inverter.  4 - 12 Volt batteries.  We went through the system and can't find anything wrong.  they system is less than 1 year.

Estragon

As a general comment, a 1hr absorb time is likely to be too short for any LA battery. I would definitely increase to 2-3 hrs. That said, temperature compensated absorb voltage is an important factor.

In order to make more specific comments, we would need more info. What is the system voltage, battery capacity and series/parallel wiring, daily ah usage, etc.

When you say the batteries are "shut off" after an hour, is this the short absorb time, or reaching an inverter low battery cut-off which stops AC power?

Photowhit

I take it it's a 24 or 48 volt system?

If they can't give you charging parameters for their batteries I would suggest returning them as they HAVE NO WARRATY, there is no way to know if you are abusing them. I'll search for a battery specs and info on line, you can do this by plugging in your battery model number and add pdf. Or search and find their site.

As @Estragon said I would be comfortable increasing your absorb to 2-3 hours with out looking too deep.

You also want to define for us what "being on" is. Unless it's a hybrid system, the batteries are in the system and are "on" all the time. What kind of loads are shutting down your system after 1 hour?

westbranch

Bill , BB  should this be combined with the other post on the same system???

The following was copied from the other thread:

What is the Manufacturers recommended time for  ABSORB?  Is your charger using a BTS or RTS ?  and YES if you are in the northern part of the world, the longer ABSORB time should help long term but you may already have damaged your batteries with only 1 Hr  of  ABSORB

Photowhit

Here's the owners manual for Outback Energycell batteries, It looks like they want you to use end amps at 1-2% of the battery capacity, but that is my interpretation of the manual.

http://www.outbackpower.com/downloads/documents/energy_storage/energycell_re/energycell_manual.pdf 

I don't know what you have, they carry a rather full line of batteries now. Here is a link to their different types of batteries.

http://www.outbackpower.com/products-mobile/tag/product-pages/Batteries

If you are reaching absorb and even just spending an hour there and your customer is running his system dry after 1 hour...

Ask if this has been happening since the system was installed. Is the Flexpower inverter being use solely off grid or as a backup system? A 2565 watt array feeding a 48 volt system should be capable of roughly 33 amps at 58 volts or 66 amps at 29 volts, can your battery bank absorb that much current? For flooded lead acid batteries you would want a rather large battery bank of 200amp hour batteries to use this high current.

Vic

Cgamer  said,   "...so the issue is after one hour of batteries being on they shut off   ..."

Guess that you are saying,   that after about one hour of use,   the inverter/s shut off,   due to LVD (?).

At least for LA batteries,   the Absorb time required to fully-charge batteries,   depends upon the Depth Of Discharge that the batteries experienced in the previous discharge.

If the above guess about what the system is doing is correct,   then  it would seem that the batteries are now being fully recharged.

We do not know about the loads on the system when there is no PV,   and we do not know the Ah Capacity of the battery bank.

A one-hour Absorb is relatively low  for most off-grid systems that are fairly well-balanced.

What is the Absorb voltage setting in the Charge Controller?
Is there an FNDC active in the system?
What is the battery bank Ah Capacity?
What are the approximate loads when the system is running on the batteries ?  OR,  what is the number of Ah removed from the batteries each night?

Thanks for more info on the system.   Vic