Steve,
So the message I am getting is even though we are always
installing a BTS, seasonal adjustments are still necessary...to both V
settings /and absorption times? /Definitely, a major part of my job in
off-grid is to assess as best as possible, the customer's system use
habits to be able to make the kinds of adjustment to which you speak.
I'm always dinking around with these settings because customers
'off-grid habits change and I don't fully trust the BTS to accurately do
its job in part because there is no perfect place to secure it...the
"best" place (the battery terminal?) leaves little space for the sensor,
plus its too far from the actual chemical reaction we are trying to
sense for accurate CC adjustments.
Please shed some light on how to deal with new batteries. My
experience is when we install a new set, they were not necessarily of
the same batch or age, sometimes I wonder how long they have been in the
"transit" chain. I've gotten into the habit of discharging the pack
~50% and adjusting up the absorb voltage and time several times to cook
them a little harder (watching temps) than settings 2-3 months down the
road.
Also, I'm curious when you say:"IEC testing requires the
batteries to come to full charge within the first 8-10 cycles" what is
their definition of "full charge"?...I can think of a few.
Thanks for your continued education on FLA batts.
Bill
On 1/19/2016 5:52 AM, Steve Higgins wrote:
Good Morning Wrenches…
I’d like to take the recent Trojan thread to throw this out there!
With the IEC certification, many battery manufactures are being forced
to recommend higher settings to charge their batteries. The problem
with off grid systems, or even some grid back up systems is the
settings can/will vary from end user to end user and can be very
difficult to determine. Try to avoid setting up a system and
assuming that those settings will be good year round as settings in
most systems need to adjusted at least twice, sometimes up to three
times a year.
For example, we are almost finished with IEC testing, the way they do
this testing in short is they take a battery, charge it to full using
mfg suggested settings, discharge it to 100% and they cycle the
battery until it comes to full capacity. Don’t quote me, but IEC
testing requires the batteries to come to full charge within the first
8-10 cycles. To do so, you need to be very aggressive on the
charging settings.
Now, most customers don’t cycle to 100% depth of discharge so end
users don’t need to be so aggressive on charger settings, but we will
be publishing revised charging parameters and instructions in the
coming quarter. Bottom line, Bulk/Absorb Voltages @ 25 Deg C you
will be advised to charge the Rolls Batteries at 2.45 to 2.5vpc. This
number will vary based on how much the customer is using the system.
A weekender cabin with a decent sized array (<10% of C20 Charge
Current) will need closer to 2.4 to 2.45vpc, while a full timer (daily
heavy cycles) will need a setting closer to the 2.5vpc rating.
Remember, regardless of where you are in the world, unless the
batteries are installed in a temperature controlled room where it
fluctuates less than ½ degree C, you should ALWAYS, ALWAYS use
battery temperature compensation. Failure to do so, will always
result in premature failure of the batteries.
Settings are generally a suggestion, the problem is they (customers)
should be looking at the SG’s at least on a quarterly basis and
adjusting settings when necessary. Lower trending SG equal higher
settings, higher SG equal lower settings. I find that too many people
set up settings and forget them, until they have a problem. Normally
I find with most customers they should have a bit lower settings from
April to Sept, while settings should be higher from Oct thru March.
Remember, the battery companies you are dealing with generally don’t
have a lot of experience in solar… they are used to industrial
applications where you see 8-12 hours of charging every single day.
We all know that in most Off grid systems you are lucky to get 3-5
hours, at best of decent charging a day.
*Steve Higgins
Technical Services Manager
***P: +1.902.597.4020
M: +1.206.790.5840
F: +1.902.597.8447
*Surrette Battery Company
*Exclusive manufacturer of
*From:*RE-wrenches [mailto:[email protected]]
*On Behalf Of *Theo Van
*Sent:* Monday, January 18, 2016 8:44 PM
*To:* RE-wrenches
*Subject:* Re: [RE-wrenches] Trojan L-16 charge settings
No "settings recommend by Trojn"were shown.
On Jan 18, 2016, at 6:43 PM, William Miller <[email protected]
<mailto:[email protected]>> wrote:
Colleagues:
I have an off-grid customer for whom I replaced a set of 8 Trojan
L-16s as well as upgrading her inverter and charge controller.
Right after the job, we found several batteries with low specific
gravity. We spoke with the local distributor and received two
replacement batteries.
The system continues to perform poorly. The customer EQs every 30
days to 60 plus volts for 3 hours. They try to get a full bulk
and absorption charge in every day but this time of year may not.
The specific gravity readings continue to diverge and generally go
lower.
We contacted the distributor who told us they have had problems
with Trojan batteries since the company was sold about two years
ago. We were told they had a brand X battery that tested better
than the Trojans. We agreed to try the Brand X but then were told
that we had not charged the Trojans adequately. Below are the
settings recommended directly by Trojan
These settings are significantly higher than any I have used
before. Also, I don’t recall it being possible to set different
bulk and absorption voltages with any of the equipment I use. I
use Trace, Outback, Schneider default settings of 57.6 bulk, 54.4
float and reprogram to 60.5 for equalization.
I am curious about what charge settings you find successful for
flooded lead-acid batteries and what any of you might think about
the recommended settings as seen below. Do you feel it is
practical to achieve these settings in an off-grid scenario?
Would these high settings cause excessive water consumption?
Thanks in advance.
William Miller
<image001.jpg>
Lic 773985
millersolar.com <http://www.millersolar.com/>
805-438-5600
I looked at the spreadsheet and the SG. readings across each
battery are uniform which tells be that it is highly unlikely that
anything is wrong with the batteries except for being
under-charged. Take a look at our User’s Guide on the Trojan
website on page 19 ( Recommended Charge Profile) or FLA batteries.
The Bulk stage should be @ 59.3V, Absorb @ 58.8V, Float @ 54V and
Equalization @ 64.8V. When the User notices drops in the SG such
as in this document, an EQ charge should be performed in order to
get the batteries back up to full charge (full charge SG being in
the range of 1.270 to 1.280. When performing the EQ, the user
should take SG reading for a “pilot” battery every 30 minutes
until the voltages reach that range. Termination should happen
when SG reaches full charge range or if battery temperature
reaches 112 degrees F, which-ever comes first. SG readings can be
taken during EQ, but you have to make sure that you bump the tiny
gas bubbles off the Hydrometer float to prevent erroneous readings.
Seeing the SG readings decreasing after each month is an
indication that maybe the Absorb Time needs to be increased, maybe
from 3 hours up to 4 or 5 hours.
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