Tech Zone
Sealed Lead Acid (VRLA) Batteries
SLA (sealed lead acid), also known as VRLA (valve regulated lead acid) batteries are rechargeable with a nominal voltage of 2 volts per cell. Require a float voltage under charge of 2.4 to 2.45 volts per cell (ex. 12 volt battery 14.4 to 14.7 volts). The amount of current the battery can take under charge is largely dependent on the capacity of the cells. Most use a 20 hour discharge to determine their rated capacity. The actual capacity is influenced by the discharge rate and voltage cutoff. Lead Acid Batteries do not develop "memory" in cyclic applications and should be kept fully charged when not in use. Top charge after 6-9 months in storage. They are constructed using an AGM (absorbed glass mat) design or GEL.
AGM batteries have a separator holding the electrolyte made of glass fiber that behaves like a sponge.
Better high rate and low temperature performance.
Faster recombination, lower resistance separator.
Can be installed in any orientation.
Lighter than the GEL construction.
GEL batteries are designed with fine silica particles with a large surface area and are dispersed in the electrolyte.
Accept a lower float voltage than AGM.
Typically provide superior cycle life.
FLOODED lead acid batteries contain a liquid electrolyte.
How to Read SLA Date Codes
YY=Year MM=Month DD=Day
Yuasa
1401173E
YYMMDD Plant/Shift
CSB
130816G11
YYMMDD No relevance to manufacture date
Panasonic
120316A
YYMMDD No relevance to manufacture date
Sonnenschein
P 4013
Plant Week YY
Power Sonic
01 164-U
MM DDY – No relevance to manufacture date
Enersys (Hawker)
14020
YY Day of the year
Enersys (NP series)
1209028B
YYMMDD No relevance to manufacture date
R&D SLA (Part numbers 5389, 5387, 5771, 5918, 5918-A)
|
Year |
Month |
|
A=2006 |
Jan=M |
|
B=2007 |
Feb=N |
|
C=2008 |
Mar=P |
|
D=2009 |
Apr=Q
|
|
E=2010 |
May=R |
|
F=2011 |
Jun=S |
|
G=2012 |
July=T |
|
H=2013 |
Aug=U |
|
I=2014 |
Sept=V |
|
J=2015 |
Oct=W |
|
K=2016 |
Nov=X |
|
L=2017 |
Dec=Y |
NT at the end of the date code has no relevance to manufacture date
IVNT = 2014 / September / No relevance to manufacture date
Non-rechargeable (Primary) Batteries
Primary batteries are a one time use and need to be replaced when the battery is exhausted.
Rechargeable (Secondary) Batteries
Secondary batteries have reversible chemical reactions so they can be recharged when exhausted and used again.
How to Read NiMH Date Codes
YY=Year MM=Month WW=Week of Year DD=Day
Energy Plus
0117556231
WW YY No relevance to manufacture date