Recei ed: 26 Ma ch 2025
Re ised: 13 Ap il 2025
Accep ed: 28 Ap il 2025
Published: 30 Ap il 2025
Ci a ion: Ma sal, E.; Ma ínez, N.;
Pé ez Vega-Leal, A.; Ba e o, F.;
Hamdan, M.; Sa ué, M.G. Au oma ic
and Ve sa ile Tes Bench o Da a
Collec ion on Ba e y Cells. Ene gies
2025,18, 2304. h ps://doi.o g/
10.3390/en18092304
Copy igh : © 2025 by he au ho s.
Licensee MDPI, Basel, Swi ze land.
This a icle is an open access a icle
dis ibu ed unde he e ms and
condi ions o he C ea i e Commons
A ibu ion (CC BY) license
(h ps://c ea i ecommons.o g/
licenses/by/4.0/).
A icle
Au oma ic and Ve sa ile Tes Bench o Da a Collec ion on
Ba e y Cells
Es eban Ma sal 1,† , Nicolás Ma ínez 1,† , Al edo Pé ez Vega-Leal 2,† , Fede ico Ba e o 2,*,† ,
Mohamad Hamdan 1,† and Manuel G. Sa ué 1,†
1Sys ems Enginee ing and Au oma ion Depa men , Uni e si y o Se ille, 41092 Se ille, Spain;
[email p o ec ed] (E.M.); [email p o ec ed] (N.M.); [email p o ec ed] (M.G.S.)
2Elec onic Enginee ing Depa men , Uni e si y o Se ille, 41092 Se ille, Spain
*Co espondence: ba e [email p o ec ed]
†Cu en add ess: Escuela Técnica Supe io de Ingenie ía, Uni e si y o Se ille, Camino de los
Descub imien os s/n, 41092 Se ille, Spain.
Abs ac : Recha geable ba e ies a e a key componen o sus ainable u u e sys ems, as hei
pe o mance di ec ly a ec s ene gy e iciency, main enance cos s, and sys em eliabili y.
Assessing pe o mance equi es e alua ing pa ame e s such as he s a e o heal h (SoH)
o he ba e y, which necessi a es de eloping a sys em capable o e icien ly ga he ing
la ge amoun s o da a. This a icle p esen s a sa e, simple, e sa ile, and au oma ed
sys em designed o es and cha ac e ize a ious ypes o ba e y cells. The sys em is
concei ed as a p ac ical ool capable o au oma ically collec ing he equi ed da a o
analysis, hus enabling he de e mina ion o he pe o mance pa ame e s o a ba e y cell.
The p oposed sys em inco po a es an inno a i e app oach based on he conca ena ion o
cha ge/discha ge da a, allowing o a mo e eliable e alua ion o ba e y pe o mance.
Expe imen al es s show he in e es and pe o mance beha io o he p oposed sys em.
Keywo ds: LiFePO
4
; li hium-ion; ba e y cycle ; ba e y ene gy managemen ; ba e y
cyclic es e
1. In oduc ion
The ansi ion om ossil uels o na u al ene gy sou ces and he g owing global
demand o sus ainable ene gy solu ions ha e led ba e y s o age sys ems o gain esea ch
and indus ial p ominence [
1
]. The a iabili y o enewable ene gy sys ems and hei
unp edic able pe o mance, wi h a high dependence on wea he condi ions, make ba e y
s o age sys ems essen ial o ensu e he s abili y o mode n elec ical g ids [
2
]. Among he
a ailable s o age echnologies, li hium ion ba e ies imp o e he o e all u iliza ion and
use ul li e o enewable ene gy due o hei high ene gy densi y and e iciency, as well
as hei low sel -discha ge a e [
3
]. Thei inhe en cha ac e is ics, coupled wi h ad ances
in powe managemen s a egies, ha e solidi ied hei epu a ion as a eliable and cos -
e ec i e ene gy s o age solu ion [
4
]. Howe e , despi e hei bene i s, hese ba e ies
deg ade o e ime because o ac o s such as loss o ac i e ma e ials o a educ ion in
li hium in en o y [
5
,
6
]. The deg ada ion mechanisms a ec hei capaci y and li e span,
and he e o e new de elopmen s in ba e y design o managemen s a egies mus be
de eloped o op imize ba e y cell pe o mance and longe i y [7].
A ypical ene gy s o age sys em consis s o mul iple ba e y cells ha , despi e man-
u ac u e s’ s anda diza ion e o s, may s ill ope a e unde di e en condi ions. This is
Ene gies 2025,18, 2304 h ps://doi.o g/10.3390/en18092304
Ene gies 2025,18, 2304 2 o 16
he case in elec ic ba e ies based on li hium-ion ba e y cells, whe e a ying e ec s de-
pending on hei applica ion appea du ing con inuous cha ge and discha ge cycles [
8
].
To minimize hese inconsis encies, i is essen ial o moni o and con ol he cha ging and
discha ging o each cell by measu ing o es ima ing key a iables such as ol age, cu en ,
and empe a u e. Compa ing hese a ia ions wi h he o e all pe o mance o he sys em
enables a mo e e icien ene gy managemen , ensu ing eliable ene gy u iliza ion [9].
The s a e o heal h SoH is he mos c i ical indica o o ba e y deg ada ion [
10
]. I
can be es ima ed h ough con inuous moni o ing o he ol age, cu en and empe a u e
using di e en al e na i es as summa ized in [
11
]. One o he simples app oaches is
di ec measu emen , which assesses SoH on he basis o capaci y ans e du ing cha ge
and discha ge cycles o by calcula ing he esis ance om ol age d ops. This me hod is
s aigh o wa d, easy o implemen , and enables eal- ime moni o ing wi hou he need
o complex models o p edic i e algo i hms [
12
]. Conside ing he impo ance o da a
a ailabili y and quali y in SoH es ima ion, all me hods o SoH es ima ion bene i om
ex ensi e da a se s ha cap u e a ious ba e y cha ge and discha ge scena ios. Reliable
da a collec ion, co e ing a ying ope a ing condi ions, ensu es accu a e SoH es ima es.
A e sa ile and au oma ed es bench can e ec i ely ackle his challenge by eplica ing
cha ging and discha ging cycles while enabling p ecise con ol and measu emen o elec-
ic ba e y pe o mance. Mo eo e , i enhances sa e y and ex ends se ice li e h ough
con inuous moni o ing and ea ly ailu e de ec ion, including o e ol age, unde ol age,
and high- empe a u e measu emen s. Real- ime da a acquisi ion and logging p o ide
deepe insigh s in o pe o mance and deg ada ion ac o s, con ibu ing o mo e e ec i e
ba e y managemen s a egies [
13
]. Howe e , implemen ing such a sys em poses se e al
challenges, pa icula ly in main aining p ecise con ol o e pa ame e s such as ol age o
cu en [14].
Many ba e y es ing benches al eady exis and ha e been p esen ed in di e en ecen
esea ch wo ks. Fo example, in [
3
], a ial sys em is p oposed wi h he capaci y o moni o
he c i ical pa ame e s o he ba e y cells. The p oposal p o ides au oma ed cha ge,
discha ge, and elaxa ion cycles, al hough i o e s a limi ed numbe o con igu a ions. I is
based on open-sou ce con ol so wa e and is cos -e ec i e, bu he sys em is cus omized
wi h a pa icula mic ocon olle , ha lacks e sa ili y because i is no easy o ep oduce
he p oposal and i canno es la ge ba e y banks o handle high cu en and ol age. A
di e en es bench o speci ic ae ospace applica ions is de ailed in [
8
], whe e he ba e y
cell is ep oduced wi h a ha dwa e in he loop echnique. The p oposal is no e sa ile
due o he di icul y o ep oducing he ini ial complex con igu a ions o he sys em. The
au ho s also epo bugs in he so wa e p o ided. In [
3
], a es bench ha includes a se o
p ocedu es o in es iga e he pe o mance o cus omized ba e y cells is p esen ed, whe e a
LabVIEW in e ace allows es selec ion, ol age and ou pu con ol, eal- ime moni o ing,
and cu o adjus men , suppo ing sa e y ope a ion o he sys em. Howe e , due o he
p og ammable esis i e load used, only a limi ed numbe o es s can be pe o med. Then,
he e sa ili y o he es bench p o ided is somehow doub ul. Finally, pa icula es
benches a e de ailed in [
15
,
16
], whe e he wo ks ocus on he a iable empe a u e con ol
o indi idual cells in a ba e y pack and on he ailu e mechanisms ha go e n he du abili y
o li hium-ion pouch cells unde ib a ion. Bo h wo ks p esen speci ic and cus omized
es benches, wi h limi ed e sa ili y.
This a icle p esen s an au oma ed, con olled da a acquisi ion sys em o es ing
li hium-ion ba e ies. The sys em inco po a es an inno a i e app oach based on he con-
ca ena ion o cha ge/discha ge da a, enabling eliable e alua ion o ba e y pe o mance. I
suppo s ully au oma ed cha ge, discha ge, and elaxa ion cycles, o e ing a high deg ee o
con igu abili y and e sa ili y. The pla o m is easy o eplica e, applicable o bo h indi id-
Ene gies 2025,18, 2304 3 o 16
ual ba e y cells and ba e y packs, and is no es ic ed o any speci ic applica ion. Ba e y
unc ionali y is alida ed h ough con inuous moni o ing and eco ding o ol age, cu en ,
and empe a u e du ing cha ge-discha ge cycles. This allows o accu a e pe o mance
e alua ion wi hou he need o complex modeling. Use s can de ine ol age and cu en
limi s, p og am au oma ic cycling ou ines, and access he collec ed da a. Da a is s o ed in
a common o ma and hos ed in an open-access eposi o y, he eby con ibu ing o ongoing
esea ch and de elopmen in he ield. O e all, he p oposed sys em p o ides an e icien
and adap able solu ion o ba e y moni o ing and managemen , ep esen ing a aluable
ool o u u e esea ch and p ac ical applica ions. The pape is s uc u ed as ollows.
Sec ion 2summa izes he undamen als o how a li hium ion ba e y no mally wo ks,
desc ibing he cha ge and discha ge p ocesses. Sec ion 3desc ibes he p oposed ba e y
es bench, de ailing he designed ha dwa e and applica ion so wa e. Sec ion 4desc ibes
some expe imen al p ocedu es pe o med o alida e he sys em, including he ealiza ion
o cha ge-discha ge cycles and he analysis o he collec ed da a o he es ima ion o he
SoH pa ame e . Conclusions a e summa ized in he las sec ion.
2. Basics o Li hium-Ion Ba e y Deg ada ion and Ope a ion
SoH is de ined as he a io be ween he maximum capaci y achie ed du ing a cha ge
o discha ge cycle (Co) and he ini ial capaci y o he ba e y (Ci), ypically exp essed as
a pe cen age: SoH (%) = (Co/Ci) × 100. The de elopmen o SoH es ima ion me hods
o li hium-ion ba e ies has unde gone signi ican ans o ma ion o e he yea s, see
Figu e 1, d i en by ad ances in ba e y echnology, compu a ional echniques, and da a
a ailabili y [17].
Al hough a common used app oach is he di ec and empi ical me hod (p e iously
e e ed o as di ec measu emen echnique in he In oduc ion sec ion), al e na i e ech-
niques such as coulomb coun ing [
18
], in e nal esis ance moni o ing [
19
], and elec ochem-
ical impedance spec oscopy (EIS) [
20
] a e used in labo a o y en i onmen s as well. These
me hods also o e ed high accu acy unde con olled condi ions by di ec ly measu ing
capaci y ade o inc eases in in e nal esis ance, bo h o which a e indica i e o ba e y
aging [
19
]. Howe e , despi e hei simplici y and physical in e p e abili y, hey p o ed
imp ac ical o eal- ime o ield applica ions. Fo example, Coulomb coun ing equi es
ull cha ge–discha ge cycles and is p one o in eg a ion e o s, while in e nal esis ance
is sensi i e o empe a u e and load a ia ions [
21
,
22
]. EIS, on he o he hand, equi es
specialized equipmen and s able en i onmen s. As a esul , hese me hods we e mainly
limi ed o o line diagnos ic [23].
Subsequen ly, he physics-based modeling echnique was in oduced o add ess he
g owing need o eal- ime SoH es ima ion in inc easingly complex ba e y sys ems such
as hose ound in elec ic ehicles and po able elec onics [
24
]. These me hods included
elec ochemical models and equi alen ci cui models (ECM), which desc ibe ba e y be-
ha io using elec ical analogs [
25
]. ECM became especially popula due o hei simplici y
and ease o implemen a ion. T acking changes in ci cui pa ame e s o e ime makes
possible o es ima e SoH, as s a ed in [
21
]. ECM p o ided mo e de ailed in o ma ion on
in e nal deg ada ion mechanisms, bu hey posed signi ican compu a ional challenges and
equi ed p ecise pa ame e iden i ica ion [26].
To imp o e obus ness and adap abili y, esea che s hen u ned o s ochas ic es ima-
ion and il e ing echniques, such as Kalman il e s (ex ended, unscen ed, and o he s) and
pa icle il e s [
17
,
27
]. These me hods enabled eal- ime es ima ion o ba e y s a es, includ-
ing SoH, e en in he p esence o noisy and incomple e senso da a [
28
]. S ochas ic il e s
adap o a ying ope a ional condi ions, manage measu emen noise, and con inuously
upda e model pa ame e s [
29
]. Howe e , i s e ec i eness hea ily depends on he accu acy
Ene gies 2025,18, 2304 4 o 16
o he unde lying ba e y model and can en ail high compu a ional cos s, pa icula ly o
nonlinea o high-dimensional sys ems [25].
Some esea che s ha e explo ed he in e es o so-called cu e analysis echniques,
including inc emen al capaci y and di e en ial ol age analysis me hods (ICA and DVA,
espec i ely) [
30
]. These echniques analyze ol age and capaci y cu es, pa icula ly
hei ime de i a i es, o de ec shi s ela ed o deg ada ion phenomena, such as loss
o li hium in en o y o ac i e ma e ial. ICA and DVA p o ide aluable in o ma ion on
he in e nal condi ion o a ba e y wi hou equi ing ull discha ges. Howe e , hey a e
sensi i e o noise and demand high- esolu ion da a, limi ing hei p ac icali y o eal- ime
applica ions [17].
An in e es ing app oach comes wi h he da a-d i en e olu ion echnique, ma ked by
he ise o machine lea ning (ML) me hods. Algo i hms such as suppo ec o machines,
andom o es s, a i icial neu al ne wo ks, deep lea ning models such as long sho - e m
memo y o ga ed ecu en uni s a e also applied o la ge-scale ba e y da ase s [
31
]. These
app oaches a e capable o modeling complex and nonlinea ela ionships be ween inpu
signals ( ol age, cu en , empe a u e) and SoH, achie ing high p edic i e accu acy and
enabling eal- ime in eg a ion wi hin ba e y managemen sys ems [
18
]. Howe e , hey
equi e la ge and di e se da a se s o e ec i e aining and o en lack physical in e -
p e abili y [
32
]. Issues such as o e i ing and limi ed gene aliza ion emain oday as
ongoing challenges [
33
]. Ongoing challenges ha e also shi ed owa d hyb id and physics-
guided app oaches, which aim o combine he ad an ages o model-based and da a-d i en
me hods. These include physics-in o med machine lea ning [
34
], mul imodel ensemble
lea ning [
28
], and hyb id il e ing echniques [
27
]. Likewise, combining Kalman il e s
wi h ML models yields obus and adap i e es ima ion sys ems [
24
]. Al hough many o
hese me hods a e s ill unde de elopmen , hey hold signi ican p omise o deploymen
in eal-wo ld applica ions, o e ing a compelling balance o accu acy, in e p e abili y, and
compu a ional e iciency [
22
]. The p os and cons summa y o he SoH es ima ion me hods
is de ailed in Table 1.
Ba e y SoH Es ima ion Me hods
Di ec and Empi ical
Me hods Coulomb Coun ing In e nal Resis ance
Moni o ing Elec ochemical Impedance
Spec oscopy
Physics-Based
Modeling Elec ochemical
Model Equi alen Ci cui
Model
S ochas ic Es ima ion
and Fil e s Kalman Fil e Pa icle Fil e
Cu e Analysis Techniques Inc emen al Capaci y
Analysis Di e en ial Vol age
Analysis Peak T acking
Da a-D i en Me hods Suppo Vec o Machines Random Fo es A i icial Neu al
Ne wo ks G adien Boos ing
Machines
Hyb id and Physics-Guided
App oaches Physics-In o med
Neu al Ne wo ks Kalman Fil e s + Machine
Lea ning Mul i-Model
Ensemble Lea ning T ans e Lea ning / Domain
Adap a ion
Figu e 1. Classi ica ion o main SoH es ima ion echniques.
The e a e se e al me hods o cha ging and discha ging li hium-ion ba e y cells, and
choosing he igh one g ea ly a ec s pe o mance, li espan, and sa e y. Acco ding o [
35
],
h ee common cha ging me hods a e cons an cu en -cons an ol age (CC-CV), cons an
loss-cons an ol age (CL-CV), and cons an powe -cons an ol age (CP-CV). Among
hese, he CC-CV me hod is widely used due o i s simplici y, eliabili y, and e iciency [
36
].
I helps educe li hium pla ing and he mal p oblems, imp o es capaci y e en ion, and
allows accu a e moni o ing o he SoH o he ba e y.
Ene gies 2025,18, 2304 5 o 16
The CC-CV me hod s a s wi h a CC phase, whe e he ba e y cha ges a a ixed cu en
un il i eaches a se ol age. Then, i swi ches o a CV phase, whe e a cons an ol age
is applied while he cu en g adually dec eases [
37
]. In compa ison, he CL-CV me hod
adjus s cu en based on ba e y impedance o con ol hea gene a ion, while he CP-CV
me hod keeps powe cons an be o e swi ching o CV mode.
Table 1. Summa y o p os and cons o SoH es ima ion me hods.
Ca ego y Rep esen a i e Me hods P os Cons
Di ec and empi ical
Coulomb coun ing, in e nal esis-
ance, elec ochemical impedance
spec oscopy
Simple implemen a ion; Physi-
cally in e p e able; High accu acy
unde lab condi ions
Requi es con olled en i onmen s;
Poo pe o mance o online es ima-
ion; Sensi i e o noise and aging
Physics-based models
Elec ochemical model, equi alen
ci cui model
Mechanis ic insigh ; Cap u es
deg ada ion mechanisms; Enables
p edic i e modeling
High compu a ional cos ; Di icul
pa ame e iden i ica ion
S ochas ic il e s Kalman il e , pa icle il e
Real- ime es ima ion; Handles
noisy/incomple e da a; Adap able
o sys em changes
Model-dependen ; Compu a ion-
ally in ensi e; Sensi i e o ini ial-
iza ion
Cu e Analysis Techniques Inc emen al capaci y analysis, di -
e en ial ol age analysis, peak
acking
Non-in asi e; De ec s speci ic
deg ada ion modes; Use ul o cell
diagnos ics
Requi es high- esolu ion da a;
Sensi i e o noise; No sui able o
eal- ime use
Machine Lea ning
Suppo ec o machines, andom
o es , a i icial neu al ne wo ks,
g adien boos ing machines
Lea ns complex nonlinea pa -
e ns; Sui able o eal- ime appli-
ca ions; Can in eg a e in o BMS
Needs la ge, labeled da ase s; Risk
o o e i ing; O en lacks physical
in e p e abili y
Hyb id & Physics-Guided
Physics-in o med neu al ne -
wo ks, Kalman il e s + Ma-
chine lea ning, mul i-model
ensemble lea ning, ans e
lea ning/domain adap a ion
Combines da a and physics; High
accu acy and gene aliza ion;
Adap i e and obus
Complex o design and une; Syn-
ch oniza ion o models is challeng-
ing; O en s ill in esea ch phase
In ou case, a CC-CV cha ging me hod is applied wi h an ini ial cha ging s age a
CC. Du ing his ini ial s age, he ba e y ol age inc eases as i accep s cha ge. When he
ba e y eaches a p ede ined ol age alue, he cha ging con inues using a CV, causing
a g adual educ ion in he cha ging cu en as he ba e y app oaches ull capaci y. This
p ocess is illus a ed in Figu e 2. The p ocedu e ends when he cu en eaches a ce ain
lowe h eshold, known as he minimum cha ging cu en poin , which is se o 0.5 A.
Figu e 2. CC-CV me hod cha ging p ocess: Vol age and cu en as a unc ion o ime.
The discha ging p ocess consis s o a con inuous discha ge a a p ede ined cu en .
Du ing discha ge, he ol age emains nea ly cons an o mos o he ime be o e g adually
Ene gies 2025,18, 2304 6 o 16
dec easing. The discha ge s ops when he ol age eaches a p ede ined lowe h eshold,
e e ed o as he minimum discha ge ol age poin . This beha io is depic ed in Figu e 3,
whe e he minimum ol age is se o 2.5 V.
Figu e 3. CC me hod discha ging p ocess: Vol age and cu en as a unc ion o ime.
3. P oposed F amewo k o Tes ing Li hium-Ion Ba e ies
The p oposed es bench is designed o pe o m cha ge and discha ge cycles on
indi idual ba e y cells. Al hough i s scalabili y allows o he ex ension o a maximum
numbe o cells, whe e he o al cha ging ol age o se ies-connec ed cells can each up o
20 V, and he maximum cha ging cu en o pa allel-connec ed cells can each up o 30 A,
in a single ba e y pack. The main ha dwa e componen s a e he ollowing:
• Pe sonal Compu e : manages and con ols he es bench.
•
Powe Supply: So ensen DLM20-30, AMETEK, Inc., Be wyn, PA, USA (600 W), p o-
iding he necessa y es ing ol age. The sys em can handle he ol age and cu en
equi ed by he single ba e y pack (up o a maximum o 20 V and 30 A supplied by
his elec onic equipmen ). This is a majo limi a ion o ou sys em. Highe ol age o
cu en es ing alues equi e ano he powe supply.
•
Rou e : D-Link D-300, D-Link Co po a ion, Taiwan, acili a ing communica ion be-
ween de ices.
•
Elec onic load: B&K P ecision 8614, B&K P ecision Co po a ion, Yo ba Linda, CA,
USA, designed o emula e ba e y cha ge and discha ge condi ions by dynamically
adjus ing ol age and cu en pa ame e s. This allows accu a e cha ac e iza ion o
ba e y pe o mance unde a ious load scena ios.
•
I/O De ice: Na ional Ins umen s USB-6281, Eme son Elec ic Co., S . Louis, MO,
USA, se ing as he es bench’s moni o ing pla o m. I enables ba e y empe a u e
measu emen and allows sys em expansion by in eg a ing addi ional elays and
ex e nal moni o ing de ices.
•
The mocouple: K ype, ensu ing accu a e he mal moni o ing by measu ing ba e y
empe a u e du ing analysis.
These componen s a e in e connec ed, as shown in Figu e 4, which p esen s he
schema ic diag am o he de eloped sys em. The es sys em connec s he ba e y in
pa allel wi h he powe supply and he p og ammable elec onic load. The he mocouple
is posi ioned a an in e media e poin on he ex e nal casing o he ba e y o moni o
empe a u e a ia ions. The powe supply is in eg a ed in o he sys em ia a local a ea
ne wo k wi h E he ne connec i i y. The ou e dynamically assigns an IP add ess o he
Ene gies 2025,18, 2304 7 o 16
powe supply h ough he Dynamic Hos Con igu a ion P o ocol. A pho o o he es
bed, whe e all he componen s a e iden i ied, is shown in Figu e 5. Du ing cha ge and
discha ge cycles, he sys em cap u es cu en alues using he in e nal senso s o he powe
supply ( o cha ging) and he p og ammable load ( o discha ging). The ol age ac oss
he ba e y e minals is measu ed using he ol age senso o he DLM20-30 powe supply.
Addi ionally, he he mocouple is connec ed o an analog inpu o he NI USB-6281 de ice,
allowing o p ecise he mal da a acquisi ion.
Figu e 4. Schema ic o he p oposed sys em o he es ing o echa geable ba e ies.
Figu e 5. Pho og aph o he designed es bench. The es ed ba e y is placed in a i ep oo box o he
ollowing dimensions: 21.5 ×15 ×17 cm.
The main cha ac e is ics o he so wa e ool de eloped o con ol he es bed a e
he ollowing:
•
I uses a LabVIEW en i onmen o con ol and moni o he es bench. The de eloped
so wa e package allows he p og amming o cha ge and discha ge cycles, eal- ime
acking o ba e y pa ame e s, and da a s o age in plain ex o ma o u he analysis.
•
Py hon ( e sion 3.12.7) was used o de elop a pos -p ocessing da a ool and gene a e
g aphical ep esen a ion o he esul s ob ained.
The acquisi ion and con ol sys em (SDAYC om now on o simplici y) was de el-
oped in he LabVIEW g aphical p og amming en i onmen . This sys em enables con ol o
Ene gies 2025,18, 2304 8 o 16
bo h he powe supply and he p og ammable elec onic load. In addi ion o i s con ol
unc ions, SDAYC p o ides eal- ime moni o ing o ol age, cu en , and empe a u e,
allowing o a comp ehensi e analysis o he ba e y’s pe o mance du ing es ing. Figu e 6
p esen s he SDAYC in e ace de eloped in LabVIEW. This in e ace no only con ols he
es bench bu also acili a es eal- ime da a acquisi ion om he ba e y unde analysis.
Figu e 6. Moni o ing and con ol en i onmen o he ba e y cha ac e iza ion.
The SDAYC includes wo ope a ing modes: manual and au oma ic. In manual mode,
he use can access he on panel Figu e 6 o manually pe o m cha ging and discha ging
ope a ions. In his mode, speci ic pa ame e s, such as cha ging ol age, cha ging cu en ,
and discha ging cu en , can be adjus ed a any ime acco ding o he equi emen s o
he desi ed expe imen al p ocess. In au oma ic mode, he use ini ially se s he alues o
cha ging ol age, cha ging cu en , discha ging cu en , minimum discha ge ol age, and
da a expo ime pe iod in seconds. The minimum cha ging cu en is ixed a a cons an
alue o 0.5 A. Once hese pa ame e s a e con igu ed, he p og am con inuously execu es
cha ging and discha ging ope a ions un il he use decides o end he p ocess. In his mode,
he cha ging p ocess au oma ically s ops when he cu en d ops below 0.5 A, while he
discha ging p ocess ends when he ol age eaches he p ede ined minimum discha ge
alue. In addi ion, a es ing pe iod o 20 min is inco po a ed be ween each cha ge and
discha ge cycle, ensu ing ha he ba e y cools down p ope ly be o e s a ing a new cycle.
In au oma ic mode, wo new independen ex iles a e gene a ed o each comple ed cycle:
one o cha ging and he o he o discha ging. This means ha e e y ime a new cha ging
o discha ging pe iod s a s, he sys em au oma ically gene a es he co esponding iles and
begins eco ding da a in hem, depending on he p ocess being ca ied ou . Addi ionally,
he SDAYC inco po a es an in e up ion sys em ha con inuously moni o s pa ame e s
such as empe a u e and cell ol age. I any o hese alues exceed an es ablished ange o i
a manual s op bu on is p essed, he p og am is au oma ically in e up ed o ensu e sys em
sa e y and p o ec he ba e y. In Figu e 7, he gene al logic o he de eloped so wa e is
shown. In bo h ope a ing modes, he ollowing pa ame e s a e eco ded: cha ging cu en ,
discha ging cu en , ba e y cell ol age, and elapsed ime. These da a a e pe iodically
expo ed as ex iles (. x ) wi h an expo in e al p ede ined by he use .
Ene gies 2025,18, 2304 9 o 16
START
AUTOMATIC MODE
CHARGING
PROCESS
YES
CHARGE
CURRENT< 0.5A
REST
20 min
VOLTAGE < MIN
VOLTAGE
TEMPERATURE > 45 ºC OR
VOLTAGE > 4.2 V OR
STOP BUTTON ACTIVATED
MANUAL MODE
NO
NO
MANUAL
DISCHARGE
PROCESS
CREATE
NEW .TXT
FILES
INTERRUPTION
STOP PROGRAM
REST
20 min
YES
YES
NO
RETURN
Figu e 7. Flowcha diag am o he so wa e de eloped.
4. Expe imen al Valida ion
To e i y he co ec ope a ion o he ba e y es bench in conjunc ion wi h he au-
oma ic mode o he SDAYC ha has been de eloped, au oma ic es s we e pe o med.
Using he da a ob ained om hese es s, cha ge and discha ge cu es and pa ame e s
such as he SoH, which cha ac e ize he ba e y’s condi ion, we e de e mined. No e ha a
s ong poin o ou p oposal is ha he e is no need o ex e nal da a p e-p ocessing o he
ep oducibili y o he expe imen s. Ou measu emen sys em is based on he ins umen s
u ilized, which p o ide he ol age and cu en o he pos -p ocessing s eps. The empe a-
u e is measu ed using a he mocouple, applying a i s o de ha dwa e il e wi h a cu -o
equency o 1 Hz.
The main speci ica ions and cha ac e is ics o he ba e y analyzed a e shown in
Figu e 8. Taking in o accoun hese cha ac e is ics, a minimum cha ging cu en h eshold
o 0.5 A was selec ed. The es ed ba e y has a nominal capaci y o 6 Ah. Al hough 0.1 C
(0.6 A) is commonly accep ed as he s anda d cu en cu -o alue, a sligh ly lowe alue
o 0.5 A was chosen acco ding o [
38
] o o e a conse a i e ma gin wi hou signi ican ly
comp omising e iciency o cha ging ime. In ou s udy, a 2.5 V cu o ol age was selec ed,
whe e a conse a i e c i e ion was applied in he selec ion o gua an ee he in eg i y and
li espan o he cell analyzed. Finally, he in e up ion sys em uses p ac ical h eshold alues
( empe a u e > 45
◦
C, ol age > 4.2 V) also ob ained om he cell speci ica ions analyzed.
Rega ding o e cha ging, ba e ies can each 4.8 V wi hou he isk o explosion o i e,
bu a sa e y ac o is applied and he h eshold ol age is educed o 4.2 V o ensu e sa e
ope a ion o he sys em. Addi ionally, he maximum ecommended empe a u e anges
o mos o he analyzed LiFePO
4
cells a y be ween 55 and 65
◦
C. Then, he maximum
sys em empe a u e in ou sys em was limi ed o 45
◦
C, which somehow conside s possible
Ene gies 2025,18, 2304 16 o 16
33.
Li, Y.; Zhang, X.; Li, Z.; Li, X.; Liu, G.; Gao, W. Accu a e and adap i e s a e o heal h es ima ion o li hium-ion ba e y based on
pa ch lea ning amewo k. Measu emen 2025,250, 117083. [C ossRe ]
34.
Chen, J.; Li, K.; Liu, W.; Yin, C.; Zhu, Q.; Tang, H. A No el S a e o Cha ge Es ima ion Me hod o LiFePO4 Ba e y Based on
Combined Modeling o Physical Model and Machine Lea ning Model. J. Ene gy S o age 2025,115, 115888. [C ossRe ]
35. Chen, G.J.; Chung, W.H. E alua ion o Cha ging Me hods o Li hium-Ion Ba e ies. Elec onics 2023,12, 4095. [C ossRe ]
36.
Liu, H.; Naq i, I.; Li, F.; Liu, C.; Sha iei, N.; Li, Y.; Pech , M. An Analy ical Model o he CC-CV Cha ge o Li-Ion Ba e ies wi h
Applica ion o Deg ada ion Analysis. J. Ene gy S o age 2020,29, 101342. [C ossRe ]
37.
Maheswa an, V.D.; Ca e , S.B.R.; Vijay, V.; Raj, S.V. S udy and Implemen a ion o Cons an Cu en -Cons an Vol age(CC-CV)
Cha ge o Li hium-Ion(Li-Ion) Ba e y Using Machine Lea ning(ML). In P oceedings o he 2024 IEEE 4 h In e na ional
Con e ence on Sus ainable Ene gy and Fu u e Elec ic T anspo a ion (SEFET), Hyde abad, India, 31 July–3 Augus 2024; pp. 1–5.
[C ossRe ]
38.
Shen, W.; Vo, T.T.; Kapoo , A. Cha ging Algo i hms o Li hium-Ion Ba e ies: An O e iew. In P oceedings o he 2012 7 h IEEE
Con e ence on Indus ial Elec onics and Applica ions (ICIEA), Singapo e, 18–20 July 2012; pp. 1567–1572. [C ossRe ]
39.
Singh, P.; Chen, C.; Tan, C.M.; Huang, S.C. Semi-Empi ical Capaci y Fading Model o SoH Es ima ion o Li-Ion Ba e ies. Appl.
Sci. 2019,9, 3012. [C ossRe ]
40.
Theue kau , D.; Swan, L. Cha ac e is ics o Open Ci cui Vol age Relaxa ion in Li hium-Ion Ba e ies o he Pu pose o S a e o
Cha ge and S a e o Heal h Analysis. Ba e ies 2022,8, 77. [C ossRe ]
Disclaime /Publishe ’s No e: The s a emen s, opinions and da a con ained in all publica ions a e solely hose o he indi idual
au ho (s) and con ibu o (s) and no o MDPI and/o he edi o (s). MDPI and/o he edi o (s) disclaim esponsibili y o any inju y o
people o p ope y esul ing om any ideas, me hods, ins uc ions o p oduc s e e ed o in he con en .
