diff --git a/borgia/__init__.py b/borgia/__init__.py
index e69de29b..71ac8661 100644
--- a/borgia/__init__.py
+++ b/borgia/__init__.py
@@ -0,0 +1,7 @@
+"""from __future__ import absolute_import, unicode_literals
+
+# This will make sure the app is always imported when
+# Django starts so that shared_task will use this app.
+from .celery import app as celery_app
+
+__all__ = ['celery_app']"""
diff --git a/borgia/celery.py b/borgia/celery.py
new file mode 100644
index 00000000..771496fb
--- /dev/null
+++ b/borgia/celery.py
@@ -0,0 +1,38 @@
+from __future__ import absolute_import, unicode_literals
+
+import os
+from celery import Celery, chain
+from celery.schedules import crontab
+from users.tasks import scan_mailing_balance_alert
+
+os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'borgia.settings')
+"""import django
+from django.conf import settings
+settings.configure()
+django.setup()"""
+
+# set the default Django settings module for the 'celery' program.
+app = Celery('borgia', backend='rpc://', broker='pyamqp://')
+
+# Using a string here means the worker doesn't have to serialize
+# the configuration object to child processes.
+# - namespace='CELERY' means all celery-related configuration keys
+#   should have a `CELERY_` prefix.
+app.config_from_object('django.conf:settings', namespace='CELERY')
+
+# Load task modules from all registered Django app configs.
+app.autodiscover_tasks()
+
+# Console log
+@app.task(bind=True)
+def debug_task(self):
+    print('Request: {0!r}'.format(self.request))
+
+
+@app.on_after_configure.connect
+def setup_periodic_tasks(sender, **kwargs):
+    sender.add_periodic_task(
+        5,
+        scan_mailing_balance_alert.s(),
+        name='Alert mailing'
+    )
diff --git a/borgia/settings.py b/borgia/settings.py
index fe01b123..fd8b278a 100644
--- a/borgia/settings.py
+++ b/borgia/settings.py
@@ -46,7 +46,8 @@
     'modules',
     'stocks',
     'graphene_django',
-	'static_precompiler'
+	'static_precompiler',
+    'django_celery_results'
 ]
 
 MIDDLEWARE_CLASSES = [
@@ -221,3 +222,6 @@
 
 CENTER_NAME = "Center Name"
 DEFAULT_TEMPLATE = "light" #Default template, en minuscule
+
+# Celery
+CELERY_RESULT_BACKEND = 'django-db'
diff --git a/borgia/urls.py b/borgia/urls.py
index 3a50750d..d6dfee31 100644
--- a/borgia/urls.py
+++ b/borgia/urls.py
@@ -25,6 +25,7 @@
 from modules.views import *
 from notifications.views import *
 from stocks.views import *
+from settings_data.views import GlobalConfig, PriceConfig, LydiaConfig, BalanceConfig
 from api.Schema.main import schema
 from graphene_django.views import GraphQLView
 from api.views import AuthGenerateJWT, AuthVerifyJWT, AuthInvalidateJWT, GraphQLJwtProtectedView
@@ -45,6 +46,18 @@
     url(r'^jwt/token/(?P<token>.+)/(?P<pk>\d+).json$', AuthVerifyJWT.as_view()),
     url(r'^jwt/invalidate/(?P<token>.+)/(?P<pk>\d+).json$', AuthInvalidateJWT.as_view()),
 
+        #####################
+        #       CONFIG      #
+        #####################
+    url(r'^(?P<group_name>[\w-]+)/config/$',
+        GlobalConfig.as_view(), name='url_global_config'),
+    url(r'^(?P<group_name>[\w-]+)/config/price/$',
+        PriceConfig.as_view(), name='url_price_config'),
+    url(r'^(?P<group_name>[\w-]+)/config/lydia/$',
+        LydiaConfig.as_view(), name='url_lydia_config'),
+    url(r'^(?P<group_name>[\w-]+)/config/balance/$',
+        BalanceConfig.as_view(), name='url_balance_config'),
+
         #####################
         #     WORKBOARDS    #
         #####################
diff --git a/borgia/utils.py b/borgia/utils.py
index 181e1591..080023e3 100644
--- a/borgia/utils.py
+++ b/borgia/utils.py
@@ -237,6 +237,21 @@ def lateral_menu(user, group, active=None):
     except ValueError:
         pass
 
+    # Global config
+    try:
+        if (Permission.objects.get(codename='change_setting')
+                in group.permissions.all()):
+            nav_tree.append(simple_lateral_link(
+                label='Configuration',
+                faIcon='cogs',
+                id='lm_global_config',
+                url=reverse(
+                    'url_global_config',
+                    kwargs={'group_name': group.name})
+            ))
+    except ObjectDoesNotExist:
+        pass
+
     if active is not None:
         for link in nav_tree:
             try:
diff --git a/celerybeat-schedule.db b/celerybeat-schedule.db
new file mode 100644
index 00000000..4b71fc74
Binary files /dev/null and b/celerybeat-schedule.db differ
diff --git a/finances/forms.py b/finances/forms.py
index a4e03525..b808abd2 100644
--- a/finances/forms.py
+++ b/finances/forms.py
@@ -220,8 +220,9 @@ def __init__(self, **kwargs):
         min_value = kwargs.pop('min_value')
         max_value = kwargs.pop('max_value')
         super(SelfLydiaCreateForm, self).__init__(**kwargs)
-        self.fields['amount'] = forms.IntegerField(
+        self.fields['amount'] = forms.DecimalField(
             label='Montant (€)',
+            decimal_places=2, max_digits=9,
             min_value=min_value,
             max_value=max_value)
         self.fields['tel_number'] = forms.CharField(
diff --git a/finances/templates/finances/self_lydia_button.html b/finances/templates/finances/self_lydia_button.html
index 080474c2..ebb5061d 100644
--- a/finances/templates/finances/self_lydia_button.html
+++ b/finances/templates/finances/self_lydia_button.html
@@ -1,5 +1,6 @@
 {% extends 'base_sober.html' %}
 {% load static %}
+{% load l10n %}
 {% load bootstrap %}
 
 {% block content %}
@@ -13,7 +14,7 @@
       <form>
         <div class="form-group">
           <label>Montant (€) :</label>
-          <input type="email" class="form-control" disabled="disabled" value="{{ amount }}" />
+          <input type="number" class="form-control" disabled="disabled" value="{{ amount|unlocalize }}" />
         </div>
         <div class="form-group">
           <label>Numéro de téléphone </label>
@@ -28,7 +29,7 @@
 <script type="text/javascript">
     $(document).ready(function() {
         $('#lydiaButton').payWithLYDIA({
-            amount: {{ amount }},
+            amount: {{ amount|unlocalize }},
             vendor_token: '{{ vendor_token }}',
             recipient: '{{ tel_number }}', //cellphone or email of your client
             message : '{{ message }}', //object of the payment
diff --git a/finances/views.py b/finances/views.py
index ee52316a..8808316c 100644
--- a/finances/views.py
+++ b/finances/views.py
@@ -1070,16 +1070,31 @@ class SelfLydiaCreate(GroupPermissionMixin, FormView,
 
     def get_form_kwargs(self):
         kwargs = super(SelfLydiaCreate, self).get_form_kwargs()
+
+        # Min value is always 0.01
         try:
-            kwargs['min_value'] = Setting.objects.get(
+            min_value = Setting.objects.get(
                 name='LYDIA_MIN_PRICE').get_value()
+            if min_value is not None:
+                if min_value > 0:
+                    kwargs['min_value'] = Decimal(min_value)
+                else:
+                    kwargs['min_value'] = Decimal("0.01")
+            else:
+                kwargs['min_value'] = Decimal("0.01")
         except ObjectDoesNotExist:
-            kwargs['min_value'] = 0
+            kwargs['min_value'] = Decimal("0.01")
+
         try:
-            kwargs['max_value'] = Setting.objects.get(
+            max_value = Setting.objects.get(
                 name='LYDIA_MAX_PRICE').get_value()
+            if max_value is not None:
+                kwargs['max_value'] = Decimal(max_value)
+            else:
+                kwargs['max_value'] = None
         except ObjectDoesNotExist:
-            kwargs['max_value'] = 1000
+            kwargs['max_value'] = None
+
         return kwargs
 
     def form_valid(self, form):
diff --git a/requirements.txt b/requirements.txt
index 3c374a0a..3095bce0 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -22,3 +22,5 @@ six==1.10.0
 typing==3.6.2
 django-static-precompiler==1.6
 openpyxl==2.4.9
+celery
+django-celery-results==1.0.1
diff --git a/settings_data/fixtures/settings.json b/settings_data/fixtures/settings.json
index 71b86178..2f4d65ae 100644
--- a/settings_data/fixtures/settings.json
+++ b/settings_data/fixtures/settings.json
@@ -4,7 +4,8 @@
     "pk": 1,
     "fields": {
       "name": "LYDIA_MIN_PRICE",
-      "description": "Valeur minimale (€) de rechargement en automatique par Lydia",
+      "description":
+        "Valeur minimale (€) de rechargement en automatique par Lydia",
       "value": "5",
       "value_type": "f"
     }
@@ -14,19 +15,43 @@
     "pk": 2,
     "fields": {
       "name": "LYDIA_MAX_PRICE",
-      "description": "Valeur maximale (€) de rechargement en automatique par Lydia",
+      "description":
+        "Valeur maximale (€) de rechargement en automatique par Lydia",
       "value": "500",
       "value_type": "f"
     }
   },
-    {
+  {
     "model": "settings_data.setting",
     "pk": 3,
     "fields": {
       "name": "MARGIN_PROFIT",
-      "description": "Marge (%) à appliquer sur le prix des produits calculés automatiquement",
+      "description":
+        "Marge (%) à appliquer sur le prix des produits calculés automatiquement",
       "value": "5",
       "value_type": "f"
     }
+  },
+  {
+    "model": "settings_data.setting",
+    "pk": 4,
+    "fields": {
+      "name": "BALANCE_THRESHOLD_MAIL_ALERT",
+      "description":
+        "Valeur seuil (€) en dessous de laquelle (strictement) l'alerte par email est activée",
+      "value": "-10",
+      "value_type": "f"
+    }
+  },
+  {
+    "model": "settings_data.setting",
+    "pk": 4,
+    "fields": {
+      "name": "BALANCE_FREQUENCY_MAIL_ALERT",
+      "description":
+        "Fréquence (jours) à laquelle l'alerte mail est envoyée si le solde est inférieur à la valeur seuil",
+      "value": "7",
+      "value_type": "i"
+    }
   }
 ]
diff --git a/settings_data/form.py b/settings_data/form.py
deleted file mode 100644
index 2f4bb2a0..00000000
--- a/settings_data/form.py
+++ /dev/null
@@ -1,27 +0,0 @@
-from django import forms
-from django.core.exceptions import ValidationError
-
-
-class UpdateSettingForm(forms.Form):
-    value = forms.CharField(label='Valeur')
-
-    def __init__(self, *args, **kwargs):
-        self.setting = kwargs.pop('setting')
-        super(UpdateSettingForm, self).__init__(*args, **kwargs)
-
-    def clean_value(self):
-        data = self.cleaned_data['value']
-
-        types = {
-            's': str,
-            'i': int,
-            'f': float,
-            'b': (lambda v: v.lower().startswith('t') or v.startswith('1'))
-        }
-
-        try:
-            types[self.setting.value_type](data)
-        except ValueError:
-            raise ValidationError('Erreur de type')
-
-        return data
diff --git a/settings_data/forms.py b/settings_data/forms.py
new file mode 100644
index 00000000..aae46ba9
--- /dev/null
+++ b/settings_data/forms.py
@@ -0,0 +1,44 @@
+from django import forms
+from django.core.exceptions import ValidationError
+from django.core.validators import MinValueValidator
+
+
+class PriceConfigForm(forms.Form):
+    margin_profit = forms.DecimalField(label='Marge appliquée aux prix en mode automatique',
+                                        decimal_places=2, max_digits=9,
+                                        validators=[
+                                          MinValueValidator(0, 'Le montant doit être positif')])
+
+
+class LydiaConfigForm(forms.Form):
+    lydia_min_price = forms.DecimalField(label='Montant minimal de rechargement',
+                                        decimal_places=2, max_digits=9,
+                                        validators=[
+                                          MinValueValidator(0, 'Le montant doit être positif')],
+                                        required=False)
+    lydia_max_price = forms.DecimalField(label='Montant maximal de rechargement',
+                                        decimal_places=2, max_digits=9,
+                                        validators=[
+                                          MinValueValidator(0, 'Le montant doit être positif')],
+                                        required=False)
+    def clean(self):
+        """
+        If min and max:
+            max >= min
+        """
+        cleaned_data = super(LydiaConfigForm, self).clean()
+        lydia_min_price = cleaned_data.get("lydia_min_price", None)
+        lydia_max_price = cleaned_data.get("lydia_max_price", None)
+        if lydia_min_price is not None and lydia_max_price is not None:
+            if lydia_max_price < lydia_min_price:
+                raise ValidationError("Le montant maximal doit être supérieur ou égal au montant minimal")
+
+
+class BalanceConfigForm(forms.Form):
+    balance_threshold_mail_alert = forms.DecimalField(label='Valeur seuil',
+                                        decimal_places=2, max_digits=9,
+                                        required=False)
+    balance_frequency_mail_alert = forms.IntegerField(label='Fréquence des emails d\'alerte',
+                                        validators=[
+                                          MinValueValidator(1, 'La fréquence doit être d\'au moins 1 jour')],
+                                        required=False)
diff --git a/settings_data/models.py b/settings_data/models.py
index 10b7130e..2a295e8b 100644
--- a/settings_data/models.py
+++ b/settings_data/models.py
@@ -84,7 +84,10 @@ def get_value(self):
         if type(self.value) is bool:
             return self.value
         else:
-            return types[self.value_type](self.value)
+            try:
+                return types[self.value_type](self.value)
+            except ValueError:
+                return None
 
     class Meta:
         permissions = (
diff --git a/settings_data/templates/settings_data/balance_config.html b/settings_data/templates/settings_data/balance_config.html
new file mode 100644
index 00000000..ce741722
--- /dev/null
+++ b/settings_data/templates/settings_data/balance_config.html
@@ -0,0 +1,17 @@
+{% extends 'base_sober.html' %}
+{% load bootstrap %}
+
+{% block content %}
+<div class="panel panel-default">
+  <div class="panel-heading">
+    Configuration des porte monnaies
+  </div>
+  <div class="panel-body">
+    <form method="post">
+      {% csrf_token %}
+      {{ form|bootstrap }}
+      <button class="btn btn-success" type="submit">Valider</button>
+    </form>
+  </div>
+</div>
+{% endblock %}
diff --git a/settings_data/templates/settings_data/global_config.html b/settings_data/templates/settings_data/global_config.html
new file mode 100644
index 00000000..5ef9280d
--- /dev/null
+++ b/settings_data/templates/settings_data/global_config.html
@@ -0,0 +1,100 @@
+{% extends 'base_sober.html' %}
+{% load bootstrap %}
+{% load l10n %}
+
+{% block content %}
+<div class="panel panel-default">
+  <div class="panel-heading">
+    Prix de vente
+    <a class="btn btn-default btn-xs pull-right" href="{% url 'url_price_config' group_name=group_name %}">
+      <i class="fa fa-pencil" aria-hidden="true" style="margin-right: 5px;"></i>
+      Modifier
+    </a>
+  </div>
+  <table class="table table-bordered">
+    <tr>
+      <td>Marge appliquée aux prix en mode automatique</td>
+      <td>{{ margin_profit.get_value|unlocalize }} %</td>
+    </tr>
+  </table>
+</div>
+<div class="panel panel-default">
+  <div class="panel-heading">
+    Rechargement par Lydia
+    <a class="btn btn-default btn-xs pull-right" href="{% url 'url_lydia_config' group_name=group_name %}">
+      <i class="fa fa-pencil" aria-hidden="true" style="margin-right: 5px;"></i>
+      Modifier
+    </a>
+  </div>
+  <table class="table table-bordered">
+    <tr class={% if lydia_min_price.get_value %}
+              "success"
+            {% else %}
+              "danger"
+            {% endif %}>
+      <td>Montant minimal de rechargement</td>
+      <td>
+        {% if lydia_min_price.get_value %}
+          {{ lydia_min_price.get_value|unlocalize }} €
+        {% else %}
+          pas de limite
+        {% endif %}
+      </td>
+    </tr>
+    <tr class={% if lydia_max_price.get_value %}
+              "success"
+            {% else %}
+              "danger"
+            {% endif %}>
+      <td>Montant maximal de rechargement</td>
+      <td>
+        {% if lydia_max_price.get_value %}
+          {{ lydia_max_price.get_value|unlocalize }} €
+        {% else %}
+          pas de limite
+        {% endif %}
+      </td>
+    </tr>
+  </table>
+</div>
+<div class="panel panel-default">
+  <div class="panel-heading">
+    Porte monnaie
+    <a class="btn btn-default btn-xs pull-right" href="{% url 'url_balance_config' group_name=group_name %}">
+      <i class="fa fa-pencil" aria-hidden="true" style="margin-right: 5px;"></i>
+      Modifier
+    </a>
+  </div>
+  <table class="table table-bordered">
+    <tr class={% if balance_threshold_mail_alert.get_value %}
+              "success"
+            {% else %}
+              "danger"
+            {% endif %}>
+      <td>Seuil d'alerte par mail</td>
+      <td>
+        {% if balance_threshold_mail_alert.get_value %}
+          {{ balance_threshold_mail_alert.get_value|unlocalize }} €
+        {% else %}
+          pas d'email
+        {% endif %}
+      </td>
+    </tr>
+    <tr class={% if balance_threshold_mail_alert.get_value and balance_frequency_mail_alert.get_value %}
+              "success"
+            {% else %}
+              "danger"
+            {% endif %}>
+      <td>Fréquence d'alerte</td>
+      <td>
+        {% if balance_frequency_mail_alert.get_value %}
+          {{ balance_frequency_mail_alert.get_value|unlocalize }}
+          jour{{ balance_frequency_mail_alert.get_value|pluralize:"s" }}
+        {% else %}
+          pas d'email
+        {% endif %}
+      </td>
+    </tr>
+  </table>
+</div>
+{% endblock %}
diff --git a/settings_data/templates/settings_data/lydia_config.html b/settings_data/templates/settings_data/lydia_config.html
new file mode 100644
index 00000000..112c3e7d
--- /dev/null
+++ b/settings_data/templates/settings_data/lydia_config.html
@@ -0,0 +1,17 @@
+{% extends 'base_sober.html' %}
+{% load bootstrap %}
+
+{% block content %}
+<div class="panel panel-default">
+  <div class="panel-heading">
+    Configuration du rechargement par Lydia
+  </div>
+  <div class="panel-body">
+    <form method="post">
+      {% csrf_token %}
+      {{ form|bootstrap }}
+      <button class="btn btn-success" type="submit">Valider</button>
+    </form>
+  </div>
+</div>
+{% endblock %}
diff --git a/settings_data/templates/settings_data/price_config.html b/settings_data/templates/settings_data/price_config.html
new file mode 100644
index 00000000..2798c084
--- /dev/null
+++ b/settings_data/templates/settings_data/price_config.html
@@ -0,0 +1,17 @@
+{% extends 'base_sober.html' %}
+{% load bootstrap %}
+
+{% block content %}
+<div class="panel panel-default">
+  <div class="panel-heading">
+    Configuration des prix de vente
+  </div>
+  <div class="panel-body">
+    <form method="post">
+      {% csrf_token %}
+      {{ form|bootstrap }}
+      <button class="btn btn-success" type="submit">Valider</button>
+    </form>
+  </div>
+</div>
+{% endblock %}
diff --git a/settings_data/views.py b/settings_data/views.py
index 3cf1623f..5bac583f 100644
--- a/settings_data/views.py
+++ b/settings_data/views.py
@@ -1,55 +1,247 @@
-from django.shortcuts import render
-from django.views.generic.base import View
+from django.utils.timezone import now
+from django.shortcuts import render, redirect, Http404, reverse
+
+from django.contrib.auth.models import Group
+from django.views.generic import FormView, View
+from django.core.exceptions import ObjectDoesNotExist
+
+from settings_data.forms import PriceConfigForm, LydiaConfigForm, BalanceConfigForm
 from settings_data.models import Setting
+from borgia.utils import (GroupPermissionMixin, GroupLateralMenuFormMixin,
+                          GroupLateralMenuMixin,
+                          lateral_menu)
 
-from contrib.models import add_to_breadcrumbs
-from borgia.views import FormNextView
-from settings_data.form import *
 
+class GlobalConfig(GroupPermissionMixin, View, GroupLateralMenuMixin):
+    """
+    View to manage config of the application.
 
-class ListSettingView(View):
-    template_name = 'settings_data/setting_list.html'
-    attr = {
-        'order_by': 'name',
-    }
+    Each config parameter MUST exists and are created by a fixture.
+    However, to ensure that these values still exists, they are recreated if
+    necessary in get_initial with a get_or_create.
 
-    def get(self, request, *args, **kwargs):
-        if request.GET.get('order_by') is not None:
-            self.attr['order_by'] = request.GET.get('order_by')
-        context = {
-            'query_setting': Setting.objects.all().order_by(self.attr['order_by']),
-        }
-        add_to_breadcrumbs(request, 'Liste paramètres système')
-        return render(request, self.template_name, context)
+    margin_profit default value: 5%
+    lydia_min_price default value: 5€
+    lydia_max_price default value: 500€
+    balance_threshold_mail_alert default value: -10€
+    balance_frequency_mail_alert default value: 7 days
+
+    :param kwargs['group_name']: name of the group, mandatory
+    :type kwargs['group_name']: string
+    """
+    template_name = 'settings_data/global_config.html'
+    perm_codename = 'change_setting'
+    lm_active = 'lm_global_config'
+
+    def get_context_data(self, **kwargs):
+        context = super(GlobalConfig, self).get_context_data(**kwargs)
+
+        margin_profit, created = Setting.objects.get_or_create(
+            name="MARGIN_PROFIT",
+            description="Marge (%) à appliquer sur le prix des produits calculés automatiquement",
+            value_type="f"
+        )
+        if created:
+            margin_profit.value = "5"
+            margin_profit.save()
+        context['margin_profit'] = margin_profit
+
+        lydia_min_price, created = Setting.objects.get_or_create(
+            name="LYDIA_MIN_PRICE",
+            description="Valeur minimale (€) de rechargement en automatique par Lydia",
+            value_type="f"
+        )
+        if created:
+            lydia_min_price.value = "5"
+            lydia_min_price.save()
+        context['lydia_min_price'] = lydia_min_price
 
+        lydia_max_price, created = Setting.objects.get_or_create(
+            name="LYDIA_MAX_PRICE",
+            description="Valeur maximale (€) de rechargement en automatique par Lydia",
+            value_type="f"
+        )
+        if created:
+            lydia_max_price = "500"
+            lydia_max_price.save()
+        context['lydia_max_price'] = lydia_max_price
 
-class UpdateSettingView(FormNextView):
-    form_class = UpdateSettingForm
-    template_name = 'settings_data/setting_update.html'
-    success_url = '/finances/bank_account/'
+        balance_threshold_mail_alert, created = Setting.objects.get_or_create(
+            name="BALANCE_THRESHOLD_MAIL_ALERT",
+            description="Valeur seuil (€) en dessous de laquelle (strictement) l'alerte par email est activée",
+            value_type="f"
+        )
+        if created:
+            balance_threshold_mail_alert.value = "-10"
+            balance_threshold_mail_alert.save()
+        context['balance_threshold_mail_alert'] = balance_threshold_mail_alert
+
+        balance_frequency_mail_alert, created = Setting.objects.get_or_create(
+            name="BALANCE_FREQUENCY_MAIL_ALERT",
+            description="Fréquence (jours) à laquelle l'alerte mail est envoyée si le solde est inférieur à la valeur seuil",
+            value_type="i"
+        )
+        if created:
+            balance_frequency_mail_alert.value = "7"
+            balance_frequency_mail_alert.save()
+        context['balance_frequency_mail_alert'] = balance_frequency_mail_alert
+
+        return context
 
     def get(self, request, *args, **kwargs):
-        add_to_breadcrumbs(request, 'Modification paramètre système')
-        return super(UpdateSettingView, self).get(request, *args, **kwargs)
+        context = self.get_context_data(**kwargs)
+        return render(request, self.template_name, context=context)
+
+
+class PriceConfig(GroupPermissionMixin, FormView, GroupLateralMenuFormMixin):
+    """
+    Each config parameter MUST exists and are created by a fixture.
+    However, to ensure that these values still exists, they are recreated if
+    necessary in get_initial with a get_or_create.
+
+    margin_profit default value: 5%
+    """
+    template_name = 'settings_data/price_config.html'
+    perm_codename = 'change_setting'
+    lm_active = 'lm_global_config'
+    form_class = PriceConfigForm
+
+    def get_initial(self, **kwargs):
+        initial = super(PriceConfig, self).get_initial(**kwargs)
+
+        margin_profit, created = Setting.objects.get_or_create(
+            name="MARGIN_PROFIT",
+            description="Marge (%) à appliquer sur le prix des produits calculés automatiquement",
+            value_type="f"
+        )
+        if created:
+            margin_profit.value = "5"
+            margin_profit.save()
+
+        initial['margin_profit'] = margin_profit.get_value()
+        return initial
 
     def form_valid(self, form):
-        setting = Setting.objects.get(pk=self.kwargs['pk'])
-        setting.value = form.cleaned_data['value']
-        setting.save()
-        return super(UpdateSettingView, self).form_valid(form)
-
-    def get_initial(self):
-        setting = Setting.objects.get(pk=self.kwargs['pk'])
-        initial = super(UpdateSettingView, self).get_initial()
-        initial['value'] = setting.value
+        # Margin profit
+        margin_profit = Setting.objects.get(name="MARGIN_PROFIT")
+        margin_profit.value = form.cleaned_data['margin_profit']
+        margin_profit.save()
+        return redirect(reverse('url_global_config',
+                        kwargs={'group_name': self.group.name}))
+
+
+class LydiaConfig(GroupPermissionMixin, FormView, GroupLateralMenuFormMixin):
+    """
+    Each config parameter MUST exists and are created by a fixture.
+    However, to ensure that these values still exists, they are recreated if
+    necessary in get_initial with a get_or_create.
+
+    lydia_min_price default value: 5€
+    lydia_max_price default value: 500€
+    """
+    template_name = 'settings_data/lydia_config.html'
+    perm_codename = 'change_setting'
+    lm_active = 'lm_global_config'
+    form_class = LydiaConfigForm
+
+    def get_initial(self, **kwargs):
+        initial = super(LydiaConfig, self).get_initial(**kwargs)
+
+        lydia_min_price, created = Setting.objects.get_or_create(
+            name="LYDIA_MIN_PRICE",
+            description="Valeur minimale (€) de rechargement en automatique par Lydia",
+            value_type="f"
+        )
+        if created:
+            lydia_min_price.value = "5"
+            lydia_min_price.save()
+        initial['lydia_min_price'] = lydia_min_price.get_value()
+
+        lydia_max_price, created = Setting.objects.get_or_create(
+            name="LYDIA_MAX_PRICE",
+            description="Valeur maximale (€) de rechargement en automatique par Lydia",
+            value_type="f"
+        )
+        if created:
+            lydia_max_price = "500"
+            lydia_max_price.save()
+        initial['lydia_max_price'] = lydia_max_price.get_value()
         return initial
 
-    def get_form_kwargs(self):
-        kwargs = super(UpdateSettingView, self).get_form_kwargs()
-        kwargs['setting'] = Setting.objects.get(pk=self.kwargs['pk'])
-        return kwargs
+    def form_valid(self, form):
+        # Lydia min price
+        lydia_min_price = Setting.objects.get(name="LYDIA_MIN_PRICE")
+        if not form.cleaned_data['lydia_min_price']:
+            lydia_min_price.value = ''
+        else:
+            lydia_min_price.value = form.cleaned_data['lydia_min_price']
+        lydia_min_price.save()
+        # Lydia max price
+        lydia_max_price = Setting.objects.get(name="LYDIA_MAX_PRICE")
+        if not form.cleaned_data['lydia_max_price']:
+            lydia_max_price.value = ''
+        else:
+            lydia_max_price.value = form.cleaned_data['lydia_max_price']
+        lydia_max_price.save()
+        return redirect(reverse('url_global_config',
+                        kwargs={'group_name': self.group.name}))
 
-    def get_context_data(self, **kwargs):
-        context = super(UpdateSettingView, self).get_context_data(**kwargs)
-        context['setting'] = Setting.objects.get(pk=self.kwargs['pk'])
-        return context
+
+class BalanceConfig(GroupPermissionMixin, FormView, GroupLateralMenuFormMixin):
+    """
+    Each config parameter MUST exists and are created by a fixture.
+    However, to ensure that these values still exists, they are recreated if
+    necessary in get_initial with a get_or_create.
+
+    balance_threshold_mail_alert default value: -10€
+    balance_frequency_mail_alert default value: 7 days
+    """
+    template_name = 'settings_data/balance_config.html'
+    perm_codename = 'change_setting'
+    lm_active = 'lm_global_config'
+    form_class = BalanceConfigForm
+
+    def get_initial(self, **kwargs):
+        initial = super(BalanceConfig, self).get_initial(**kwargs)
+
+        balance_threshold_mail_alert, created = Setting.objects.get_or_create(
+            name="BALANCE_THRESHOLD_MAIL_ALERT",
+            description="Valeur seuil (€) en dessous de laquelle (strictement) l'alerte par email est activée",
+            value_type="f"
+        )
+        if created:
+            balance_threshold_mail_alert.value = "-10"
+            balance_threshold_mail_alert.save()
+        initial['balance_threshold_mail_alert'] = balance_threshold_mail_alert.get_value()
+
+        balance_frequency_mail_alert, created = Setting.objects.get_or_create(
+            name="BALANCE_FREQUENCY_MAIL_ALERT",
+            description="Fréquence (jours) à laquelle l'alerte mail est envoyée si le solde est inférieur à la valeur seuil",
+            value_type="i"
+        )
+        if created:
+            balance_frequency_mail_alert.value = "7"
+            balance_frequency_mail_alert.save()
+        initial['balance_frequency_mail_alert'] = balance_frequency_mail_alert.get_value()
+        return initial
+
+    def form_valid(self, form):
+        # balance_threshold_mail_alert
+        balance_threshold_mail_alert = Setting.objects.get(name="BALANCE_THRESHOLD_MAIL_ALERT")
+        if not form.cleaned_data['balance_threshold_mail_alert']:
+            balance_threshold_mail_alert.value = ''
+        else:
+            balance_threshold_mail_alert.value = form.cleaned_data['balance_threshold_mail_alert']
+        balance_threshold_mail_alert.save()
+        # balance_frequency_mail_alert
+        balance_frequency_mail_alert = Setting.objects.get(name="BALANCE_FREQUENCY_MAIL_ALERT")
+        if not form.cleaned_data['balance_frequency_mail_alert']:
+            balance_frequency_mail_alert.value = ''
+        else:
+            balance_frequency_mail_alert.value = form.cleaned_data['balance_frequency_mail_alert']
+        balance_frequency_mail_alert.save()
+        return redirect(reverse('url_global_config',
+                        kwargs={'group_name': self.group.name}))
+
+
+# TODO: min < max, check for '' value in views, ensure min, max, values are respected in views
diff --git a/users/tasks.py b/users/tasks.py
new file mode 100644
index 00000000..6848b4a1
--- /dev/null
+++ b/users/tasks.py
@@ -0,0 +1,104 @@
+from __future__ import absolute_import, unicode_literals
+from celery import Celery, chain, current_app
+from celery.schedules import crontab
+from django.core.mail import send_mail
+from django.template.loader import render_to_string
+
+from django.core.exceptions import ObjectDoesNotExist
+
+# set the default Django settings module for the 'celery' program.
+app = current_app
+
+@app.task
+def scan_mailing_balance_alert():
+    for user in get_concerned_users_balance_mailing_alert():
+        mailing_process = chain(mail_alert_balance.s(user))
+        mailing_process()
+    return True
+
+@app.task
+def mail_alert_balance(user):
+    """
+    Send an email to alert about low balance.
+    """
+    from settings_data.models import Setting
+
+    threshold = Setting.objects.get(name="BALANCE_THRESHOLD_MAIL_ALERT").get_value()
+
+    msg_plain = render_to_string('users/mail_alert_balance.txt', {})
+    msg_html = render_to_string('users/mail_alert_balance.html', {})
+
+    send_mail(
+        'email title',
+        msg_plain,
+        'ae.ensam.assoc@gmail.com',
+        [user.email],
+        html_message=msg_html,
+    )
+    print(f'mailing alert balance: {user.__str__()}')
+
+def get_concerned_users_balance_mailing_alert():
+    """
+    Return users concerned by the mailing alert concerning the balance.
+    Threshold & frequency must be defined for filtering.
+
+    :returns: [] if threshold or frequency is None or if both settings aren't defined.
+    :returns: [Users]
+    """
+    # Set up Django for models
+    import django
+    django.setup()
+    from settings_data.models import Setting
+    from users.models import User
+    from django.contrib.auth.models import Group
+
+    try:
+        threshold = Setting.objects.get(name="BALANCE_THRESHOLD_MAIL_ALERT").get_value()
+        frequency = Setting.objects.get(name="BALANCE_FREQUENCY_MAIL_ALERT").get_value()
+
+        if threshold is not None and frequency is not None:
+            return User.objects.filter(balance__lt=threshold, is_active=True).exclude(
+                groups=Group.objects.get(name='specials'))
+        else:
+            return []
+    except ObjectDoesNotExist:
+        return []
+
+
+"""
+
+from __future__ import absolute_import, unicode_literals
+
+from celery import Celery, chain
+from celery.schedules import crontab
+#from settings_data.models import Setting
+
+# set the default Django settings module for the 'celery' program.
+app = Celery('borgia', backend='rpc://', broker='pyamqp://')
+
+@app.task
+def scan_for_expired_users():
+    for user in get_expired_users():
+        deactivating_process = chain(deactivate_account.s(user), send_expiration_email.s())
+        deactivating_process()
+
+
+@app.task
+def deactivate_account(user):
+    # do some stuff
+    print(f'deactivating account: {user}')
+    return user + '_deactivated'
+
+
+@app.task
+def send_expiration_email(user):
+    # do some other stuff
+    print(f'sending expiration email to: {user}')
+    return True
+
+
+def get_expired_users():
+    return (f'user_{i}' for i in range(5))
+
+
+"""
diff --git a/users/templates/users/mail_alert_balance.html b/users/templates/users/mail_alert_balance.html
new file mode 100644
index 00000000..cd087558
--- /dev/null
+++ b/users/templates/users/mail_alert_balance.html
@@ -0,0 +1 @@
+Hello world!
diff --git a/users/templates/users/mail_alert_balance.txt b/users/templates/users/mail_alert_balance.txt
new file mode 100644
index 00000000..cd087558
--- /dev/null
+++ b/users/templates/users/mail_alert_balance.txt
@@ -0,0 +1 @@
+Hello world!