Ni-cad battery user's manual

Notice

The following notes should be abided in operating:

1.Fireproofing
This series of battery can generate explosive gas (hydrogen and oxygen).
Battery room must contain ventilation devices and keep away from naked fire.
Explosive gas is generated when the low capacity cells are doing recovery charging in regular complementary charging.
2.Electrolyte
Rubber gloves and other protective supplies should be worn before using electrolyte.
If electrolyte spills on human body or clothings, please wash it with plentiful clean water.
If electrolyte spills into eyes, wash with clean water, then go to the hospital at once.
3.No short circuit at the terminals of the battery
Please pay special attention when installing batteries (especially to installing and connecting parts), avoiding short circuit on both terminals caused by tools and metals.
Any tools are forbidden to put in battery case.
4.Others
    Other notes will be mentioned in the other Chapters of the manual.

1  Pocket Type Nickel Cadmium Rechargeable
Battery Basics

1.1 Brief introduction
   Nowadays, the most popular rechargeable batteries in industrial application are nickel cadmium battery and lead acid battery. Thereinto, nickel cadmium battery’s maintenance is easier, and its service life is longer. The manual is mainly described installation and maintenance of the battery, which is helpful for knowing well about structure, performance and correct maintenance methods. Before operating, please read the manual carefully.

1.2 Structure
   We can provide 3 kinds of pocket type alkaline batteries: KPH, KPM, and KPL. For KPH series, it is high discharge rate, which is mainly applied in engine & gas turbine starting, and control system of power plant; for KPM series, it is medium discharge rate, which is applied in emergency power station, switch & control system, construction emergency lighting, train control system and so on; for KPL series, it is low discharge rate, which is applied in emergency lighting, railway signal lamps, alarm systems, shipping and so on.

1.2.1 Single cells
1)Plates assembly
   The important parts of pocket type battery are positive plates and negative plates. Their structures are the same, only the active materials are different, positive is made up of nickel hydroxide and graphite, while negative is made up of cadmium hydroxide. Active materials are enwrapped in perforation iron strips, spliced into rectangular rough plates by mechanical strength, and fixed to be flat ones like coverlets by plate frames.
   Several plates with the same polarity are assembled and welded with current-collecting plates which are connected with terminal poles, according to a certain distance, and then positive/negative plate groups are made.  
2 plate groups, 1 positive plate group, 1 negative plate group, are assembled together according to positive and negative sequence, that is, positive-negative-positive, arranged in turn.   
  The assembled plates are set off by separators.
2)Container
   Plate groups are assembled in the container, which is made of engineering plastic with strong structure.
3)Electrolyte
   Electrolyte for pocket type battery is commonly KOH aqueous solution with a little LiOH, which is specified in Article 4.4~4.6 and Chapter 5.
4)Other parts
   A few spare parts of the battery are made of rubber or synthetic resin, while most are made of plating nickel steel parts. Therefore, the whole structure has higher mechanical strength.

1.2.2 Battery packs
   According to the requirements of operating voltage, 2 or more cells assembled in the crates are to be battery pack. Single cells are connected by intercell connectors, for convenient transportation, handles are always installed on the crates, the quantity of single cells in the battery pack lies on its basic dimension and weight.

1.3 Chemical reaction in charging and discharging
   For pocket type nickel cadmium rechargeable battery, Ni(OH)2 is used as positive materials, while Cd(OH)2 is used as negative materials. Electrolyte is KOH aqueous solution with a little LiOH, to improve service life and high temperature performance of the battery. Electrolyte works only for ion transmitting in charging and discharging, chemical reaction or attenuation won’t happen. While for lead acid battery, chemical reaction will be occurred between positive and negative materials with vitriol, leading to ageing.
For lead acid battery, its basic structure of positive and negative plates is Pb and PbO2, which will participate in chemical reaction in operating, and is easily to be corrupted. While the plate frame of ni-cad battery is metal strip with high mechanical strength, and chemical reaction won’t occur in operating. NiOOH is transformed into Ni(OH)2 on positive pole in discharging, while metal Cd is transformed into Cd(OH)2 on negative pole. Reverse reaction occurs in charging, till the voltage rises to the level that can separate H2 out on negative pole, and O2 on positive pole, then it leads to water decomposition. Compared with lead acid battery, the difference is that the electrolyte density is appreciably changed after charging and discharging. Therefore, according to the comparison on electrochemistry performance, it’s easy to see that ni-cad battery has the features of higher stability, long service life, and abuse resistance. Its nominal voltage is 1.2V.

Charging & discharging reaction as follows:

Charging

2Ni(OH)2+Cd(OH)2    Cd+2βNiOOH+2H2O
Discharging

1.4 Characteristics of the battery

(1)Rated capacity
Battery capacity is calculated by Ampere-Hour (Ah), under the ambient temperature of 20℃±5℃, its capacity can supply the load of 0.2ItA for 5h, after being fully charged by 0.2ItA for 8h, which can meet the requirements of IEC Standards.

2)Voltage
   The open circuit voltage of single cell is 1.3V~1.5V, any changes in this range is normal, which lies on the time in the state of keeping open circuit after being fully charged, and it also has relations with charging condition, discharging current, ambient temperature and essential resistance of the battery.
   The nominal voltage of single cells is the electric potential difference, generated by nickel and cadmium ions dissociating in KOH electrolyte, it is 1.2V, and the nominal voltage of battery pack is 1.20×n (“n” indicates the quantity of single cells in series).
(3)Relations between discharge rate and capacity

    Capacity is changed following discharge rate, the bigger the discharge is the smaller the capacity is. The capacity is considered as 100% once discharged by the standard rate (0.2ItA) for 5h at 20℃.
(4)Essential resistance
   Essential resistance of the battery is related to the state of charge, thus it’s hard to define and measure it accurately. Based on fully charged state under normal temperature, the essential resistance is 20% higher when discharged by 90%, and it is 80% higher when discharged by 90%, once the temperature is lower, it also will be bigger, for instance, it will be 15% higher under 0℃ than that under normal temperature.

2 Installation of the Battery

2.1 Condition of battery room

Battery room must meet the following requirements:

(1) Battery room should be separated with other rooms, acid battery cannot be placed with alkaline battery in the same room;
(2) The battery should avoid highlight, and keep away from fire source;
(3) Thermostat should be installed in the room, and keep it in the range of 20℃±10℃;
(4) The ventilation is good in the room.

2.2 Unpacking and inspection

(1)Inspect the goods whether it is damaged or not Unload carefully avoiding to be impacted. Be sure unloading the goods near battery room, catch hold of the bottom of the battery when conveying. The terminal poles of the battery should keep upwards; any sundries cannot be put on the top of the ba ttery.
(2)check the goods according to the packing list Check whether the goods are complete or not according to the list, the containers of the battery are damaged or not in transportation, the metal spare parts outside the battery are rust or not, the nuts under the terminal poles are loosened or not, and any other related proceeding. If any questions, please contact us.
 

2.3 Electrolyte filling

   The battery always leaves the factory unfilled, thus fill the electrolyte first before operation, after that keep the plates dipped in it for 4h, then do initial charge according to Article 3.2 in the manual. If the battery is unused for some time, please store it according to Article 4.7.
(1)Fill electrolyte
   Take off transportation vent plugs before filling electrolyte. Slowly fill it over the min. level.
(2)Adjust electrolyte level
   30 minutes later after filling electrolyte, check whether the level is fall or not, if it is, fill it slowly to the max. level. 2h later after initial charge finishing, fill electrolyte to the max. level.

2.4 Installation

2.4.1 Position

Installation position of the battery should meet the requirements in Article 2.1. When the ambient temperature is 20℃±5℃, the battery can show its best electric performance and service life. It can be installed on the battery stands, in the battery cabinet, even on the open ground. When installing, it is better to leave a passage among battery packs, whi ch is convenient for personnel to do further maintenance. If the battery is installed in the airtight room, ventilating devices must be installed, so that the gas generated in charging can be vented, or it may cause explosion.

2.4.2 Ventilation

   When the battery is installed in small room or closed carriage, ventilation devices are always required. In late charging, the battery will vent gas (mixed gas of H2 and O2). When installing reasonable ventilation systems in the battery room, it is necessary to calculate the producing speed of H2, and ensure the consistency of H2 produced in the room keeps in a safe range. The theoretic safe limit consistency of H2 is 4%.
   The exhaust requirement in the battery room can be calculated according to the following methods:

   1Ah overcharge can electrolyze 0.366㎝3 water of, while 1㎝3 water can produce 1.865L gas, proportionately H2:O2=2:1. Accordingly, 1Ah overcharge can produce 0.42L H2.
   Therefore, H2 release per hour in battery pack=quantity of single cells×charging current×0.42L or =quantity of single cells×charging current×0.00042m3.
   The H2 release calculated above can be put into gas proportion that H2 occupies in the battery room, and then the required air can be calculated, when keeping H2 in a certain consistency.
   For instance:

   A battery pack assembled by 98 pcs KPH70 is placed in the room of 2m×2m×3m, for 2 steps, in 2 rows, charge it by the current of 0.2C5, that is 14A. Then the H2 release per hour at least is:
   98×14×0.00042 m3=0.58 m3  
   The total volume of the room is  2×2×3=12 m3      The volume of battery and steps will not over 1 m3, and then the gas volume in the room is 11 m3. The produced gas consistency that charged by the current of 0.2C5 for1h is

   If the consistency in the room can keep in the proportion of 3%, then the exchanging times of gas should be:

   Generally, for common rooms with doors and windows, the self-updating quantity of gas is 2.5%/h. In this way, it is necessary to install forced ventilation devices, and at least open it per hour exchanging the gas in the room. In floating charge, current is much lower than that under normal charge conditions and the gas release is the least. Only knowing the current of floatingcharge, the H2 release can be calculated by the same methods.

2.4.3 Installation of battery stand

  Battery stand is used for holding battery; install it first before installing the battery. Each stand must be placed horizontally, so that each single cell can be placed vertically, or the battery performance may be affected. Whether the cells are placed in order or not, which can be seen by the position relations between electrolyte level and label line. When the stand is not flat, a piece or a few pieces PVC board or tiny float materials can be used under the stand to keep it horizontally.

2.4.4 Arrangement

   Now the single cells can be put on the battery stand, since the cells are heavy with electrolyte, please carefully move them.
   When conveying, be sure that the terminal poles are made upwards. The cells must be put on end, and install carefully according to arrangement drawings, avoiding polarity confusion.
   If you are not familiar with arranging cells, please read this article carefully, this will help you a lot. Our company has much experience in this field, whether on the stand, in the cabinet, or on the open ground, it must obey definite principles, generally there are 2 ways. The first is connection in length direction, seeing Figure A; the second is in width direction, seeing Figure B.

                    

                Figure A   In Length Direction                                       Figure B   In Width Direction

   When placing the battery, please refer to the following methods, and calculate how to arrange it:

1)Calculate the quantity of battery packs;
2)The length of installation area divided by the length (arranged in Figure A) or the width (arranged in Figure B) of single cells, work out the max. quantity of single cells that can be arranged in a row;
3)The width of installation area divided by the width (arranged in Figure A) or the length (arranged in Figure B) of single cells, work out the rows that can be arranged;
Let’s give an example to explain how to arrange the battery. For example:
A 3-tiers cabinet can hold 60 pcs single cells KPL20, length (single cell) ×width=32×113(mm). length (each tier) ×width=340×250(mm).
The quantity of single cells arranged in each row=340/32=10 cells;
The quantity of rows=250/113=2 rows;
At most 20 cells can be arranged in each tier, so for 3-tiers, 60 cells can be arranged.
This calculation method is not only applicable for cabinet, but also for battery stand.

2.4.5 Connection

   Connect single cells with proper spare parts (intercell connectors, flexible cables) according to the connection drawings, and tighten each nut by spanner.

Table 1 Comparison Between Nuts and Torque Moment

3 Initial Charge and Storage

3.1 Preparation before initial charge

 After installing and connecting, the battery should be fully  charged as soon as possible, before that, please inspect AC current and the charger, ensuring they can be normally operated, measure the voltages of battery pack and single cells, electrolyte consistency and temperature, ensuring there is no problem. Then connect the positive poles, and the negative poles correspondingly of the battery and the charger.

3.2 Charging

   Each cell should be charged according to the standard current (0.2ItA), cells of the same model can be charged together, while the different models cannot be charged together. In charging, the temperature of electrolyte is slowly rising. If it rises over 45℃, it will be harmful to the battery, the charging should be stopped at once, when the temperature is down below 45℃, continue charging. Fill the Table of Records indicated as Table 2, and record charging details.

3.3 Treatment after initial charge

   After initial charge, since the battery needs to do all kinds of performance tests, it will be discharged more or less, before operation, it should be charged by the current of 0.2ItA for 8h.
   Notes: check whether the electrolyte level is normal or not after charging, if it is much lower than the max. level, please fill distilled water or deionized water to the proper level.

3.4 Storage after initial charge

 If the battery cannot be used at once after initial charge, the following methods should be done:
   The capacity of fully charged battery in storage will lower gradually, owing to its self-discharge. If the fully charged battery cannot be put into use for more than 1 year, please store it according to Article 4.7.1 in the manual, If less than 1 year, please store it according to Article 4.7.2, and fully charge the battery when you reuse it.

4 Maintenance

4.1 Charge

The battery is generally charged by DC. Connect the positive poles, and the negative poles correspondingly of the battery and the charger. When the voltage rises to 1.65V/cell~1.80 V/ cell constantly for 2.5h~3h in charging, it is fully charged. In practical operation, standard charge, floating charge or equalization charge may be chosen, the settings of the 3 charging methods are as follows.

4.1.1 Standard charge
In normal situation, we suggest standard charge in battery maintenance, that is being charged by the current of C5 (0.2ItA) for 8h.

4.1.2 Floating charge

When the battery is in parallel connection with charger and load, as a supporting power supply, it keeps smaller current in charging at this moment, automatically recover the lost capacity in discharging owing to self-discharge or other operations, this is floating charge.
   In floating charge, the battery keeps in sufficient state, so it only can be a supporting power supply, when the power is cut or the voltage is not enough, the battery would supply power to the load. The floating charge of single cells is always b  e 1.40V/cell~1.50V/cell, and the current of floating charge is about 1/40 of C5 (0.005ItA). The setting of charging voltage should be properly adjusted according to battery types and operation conditions; excessive water consumption means the charging voltage is too high, if the battery capacity is not enough, that is the setting of charging voltage is too low.
   When the battery is operating as standby power supply with load in parallel connection, the voltage of floating charge is related to battery types. It should be set according to Table 3 in operation.

Table 3 The Voltages of Floating Charge for Different Types of Battery

Type Voltage of Floating Charge(V/cell)
KPH 1.41~1.43
KPM 1.42~1.45
KPL 1.45~1.50

   Floating charge voltage of the battery pack=floating charge voltage of single cell×the quantity of single cells in series.

4.1.3 Equalizing charge

   If the battery is in floating charge for a long time, or obvious difference of its voltage appears, equalizing charge would be done for 12h. The voltage of equalizing charge is related to the battery types, the settings of charging voltage should be properly adjusted according to the battery types and the operation conditions, the details please refer to Table 4. After equalizing charge for 12h, the voltage of charging devices should be adjusted to the floating charge voltage.

Table 4 The Voltage of Equalizing Charge for the Cells of Different Types

Type Voltage of Equalizing Charge(V/cell)
KPH 1.60~1.65
KPM 1.60~1.65
KPL 1.65~1.70

   Equalizing charge voltage of the battery pack=equalizing charge voltage of single cell×the quantity of single cells in series.
   In charging, the voltage of the battery should reach the values in a short time. If it cannot reach the values after equalizing charge being finished, please adjust its charging voltage.

4.2 Temperature influences

   Temperature is an important factor that can affect the performance of the battery. In charging, the most proper temperature is 20℃±5℃. Generally, the electrolyte temperature in the battery increases gradually along with charging, when it rises to 45℃, the service life will be affected, thus it should be controlled in this range. However, if the electrolyte temperature could keep over 45℃ for a short time, and would not destroy the battery, it would not make the capacity fall fast.

4.3 Electrolyte refilling

   Water electrolyzing and vaporizing often happen in the battery, leading to the reduction of electrolyte level. That is why the electrolyte needs to refill frequently, to keep the level between the min. and the max. or between the top of plates and the max.
   There are 2 lines on both sides of the single cells, the max. level and the min. level. Being observed by naked eyes from the outside, the electrolyte must be kept between the max. and the min. level, if required, fill distilled water or deionized water.

4.4 Preparation of electrolyte and notices

   For electrolyte preparation, glass, figuline, alkali-resistant plastic, nickel, stainless steel vessels are required, copper, aluminium, colophony or wooden ones are not permitted, or it would be corrupted by lye. The detailed methods of preparation refer to Article 5. It must be noticed in particular that the electrolyte must be accorded with the technical requirements of the company, or the battery would be destroyed permanently. The consistency should be adjusted according to electrolyte temperature, it is considered as the standard when the temperature is 20℃, once it falls for each 1℃, the consistency increases by 0.0005, while it rises for each1℃, the consistency decreases by 0.0005. Electrolyte can absorb CO2 in the air easily; accordingly generate K2CO3, which will lower the capacity of the battery. Therefore, the electrolyte must be stored in airproof pot, avoiding to absorb CO2 in the air and be polluted.
   Electrolyte will burn skin, destroy and pollute clothes. If it is treated improperly, the skin will be inflamed. It must be paid special attention that if the electrolyte spatters into eyes, or the sequent would be much worse than the vitriol’s, it needs medication as soon as possible. It can be treated by weak acid, if the skin is burned, such as vinegar or boric acid of 3%. 

4.5 Electrolyte replacement

In operation, the electrolyte in the battery absorb CO2 in the air easily, and generate carbonate, increasing internal resistance of the battery, when the content of carbonate is over 60g/L or the capacity is lower caused by pollution for other reasons, the electrolyte should be replaced in time; in floating charge, check the content of carbonate every 3 years, when it is over the stipulated value, replace the electrolyte in time. The method is: discharge the battery to 1.0V/cell, open the vent plug, inverse and shake the battery, let the dust deposition inside pour out with electrolyte. If the poured electrolyte is too dirty, wash the inside of the battery for 2~3 times by the water for electrolyte preparation, pour it out completely, then fill new prepared electrolyte.

When the following situations appear, please replace the electrolyte:

1)the electrolyte consistency falls below 1.16;
2)the battery cannot be normally operated, when it is discharged according to the standards;
3)the content of impurities in electrolyte (especially heavy metals) is over the max. permitted limit.
After replacement, if the battery is not used as once, treat it with the following methods, the capacity can be recovered. Before charge, please clean the battery first, then arrange and connect it according to the previous order.
a)being charged by C5(0.2ItA)for 12h, or charged by C10(0.1ItA)for 24h (charged by 240% of the rated capacity).
b)being discharged by C5(0.2ItA) to 1.0V (the voltage of single cell).
c)being charged according to a)once again, then it can be operated.
Notes: after all the cells being charged, check whether the electrolyte consistency and the levels are proper or not.

4.6 Clean

Keeping the battery clean will make longer service life and better performance.
Electrolyte volatilization and gas emission will make the battery moist, and heat-moisture will lead to creepage, so the battery should keep clean and dry. Sand paper or gauze cannot be used to clean nickel plating accessories; it would destroy nickel substrate, leading to rust and resistance increase. Proper maintenance should abide by the following rules, proper and careful daily maintenance will save much expense in the future.
1) clean the exterior of the battery every month at least, especially its top and terminal poles, spread enough rust preventive oil or Vaseline oil on the nickel plating accessories.
2) screw down terminal poles and other connecting accessories frequently.
3) avoid to destroy the battery.。

4.7 Storage of the battery

4.7.1  Long-time storage

For the battery in long-time storage, after normal discharge, spill out the electrolyte and install the vent plug at once, clean its surface, if there is vent hole on the vent plug, seal it with medical plaster, terminal poles and all the metal accessories should be equably spread with a coat of Vaseline oil, stored in the ventilated and dry room without acid, its ambient temperature should not be over 35℃, and relative humidity should be not more than75%. When it is reused, fill the electrolyte according to the previous methods, and operate according to the methods of initial charge in Article 3.

4.7.2  Short-time storage

If the storage of the battery is not more than 1 year, it can be stored with electrolyte in charged or discharged state, however, before storage, adjust the electrolyte level to confirm with the regulations, screw down the vent plug, seal it with medical plaster (and plunge a vent hole on it), clean the surface, lay it in the ventilated and dry room without acid mist, and the ambient temperature should not be over 35℃.

4.8 Routine maintenance and inspection

In proper maintenance, the battery would have better performance and longer service life. Therefore, regular inspection and records for each time are very important. In this way, the problems would be found out in advance, and the reasons would also be found.

4.8.1 Routine maintenance

In maintenance, standard charge & discharge principles are recommended to do charge & discharge cycle.
The battery in floating charge for a long time should do equalizing charge every 6 months. When the voltage of single cells in the battery pack appears obvious imbalance, equalizing charge should also be done. Operate it according to Article 4.1.3.

4.8.2 Regular inspection

Do inspection according to the following table:

Table 5 Cycle Inspection

Description Frequency
Floating Charge Each Month
End Voltage of the Battery Each Three Months
Electrolyte Level Each Two Months
Degree of Tightness for Connecting Parts Each Three Months
Appearance of Container and Lid for the Battery Each Three Months
Equalizing Charge Each Six Months

4.8.3 Inspection methods

1)Floating charge: Refer to Article 4.1.2
2)End voltage of the battery: Measure by voltmeter
3)Electrolyte level: Refer to 4.3
4)Connecting parts: If bolts and nuts become loose, tighten them with spanner.
5)Appearance of container and lid: Check whether the container and the lid of the battery are damaged or not, and replace the damaged or extremely deformed container or lid at once.
6)Equalizing charge: Refer to Article 4.1.3

5 Selection, Preparation and Storage of Electrolyte

5.1 For electrolyte selection, consistency, composition or additives are determined by operating temperature of the battery, detailed requirements refer to Table 6.

Table 6

No.
Operating Temp.(℃)
consistency (g/cm3)
Composition of Electrolyte
Weight Ratio(alkaline:water)
1
-5~60
1.20±0.01
NaOH+20g/LiOH
1:3
2
-25~-5
1.25±0.01
KOH
1:2
3
-40~-25
1.28±0.01
KOH
1:2

   Remark: electrolyte consistency of the battery is 1.19 g/cm3~1.21g/cm3, correspondingly the content of each substance in 1L electrolyte is: KOH 242g~271g, water 947g~939g, LiOH·H2O 20g, which can be prepared to get 1L electrolyte of 1.19 g/cm3~1.21g/cm3 according the following methods.

5.2  The technical requirements of electrolyte refer to Table 7(take the consistency of 1.20±0.01g/cm3 as an example)

Table 7 Technical Requirements of Electrolyte

Item
Technical Requirements
New Electrolyte
Limit Value in Operation
Appearance
Colorless, transparent, no suspended substances
 
Consistency(15℃))
1.20±0.01
1.20±0.01
Content(g/l)
KOH:240~270
KOH:240~270
Cl-(g/l)
<0.1
0.2
K2CO3(g/l)
<20
60
Ca2+·Mg2+(g/l)
<0.19
0.3
Fe/KOH(%)
<0.05
0.05

5.3 Technical requirements of raw materials for preparing electrolyte

KOH: Chemical GB2306 or GB1919 for industrial application;
LiOH·H2O: LiOH-1 GB8766 and the content of LiOH cannot be less than 55%;
Water: distilled water, softened water, ion-exchange water, electro osmosis water and so on (its technical requirements refer to Table 8).
Warning: tap water, mineral water and sea water are forbidden.


Table 8 Technical Requirements of Water

No.
Item
Requirements
1
Physical property
Colorless, tasteless, transparent, and no mechanical substances
2
Resistance (ohm)
≥200000
3
Content(g/l)of Fe
≤0.00005
4
Content(g/l)of SO42-
≤0.0005
5
Content(g/l)of Cl-
≤0.001
6
Content(g/l)of heavy metal (count with Pb)
≤0.00005
7
Content(g/l)of Ca and Mg(count with Mg)
≤0.0006
8
Content(g/l)of SiO32-
≤0.0001


5.4 Vessels and tools for preparation

5.4.1 Vessels

The vessels should be plastic, stainless steel, porcelain enamel and alkali-resistant materials, which cannot be used with the ones for preparing electrolyte of acid battery together.

5.4.2 Tools

Densimeter (measuring span is 1.10~1.30), thermometer, graduated flask, funnel, plastic spoon and platform balance; stirrer would be used for preparing plentiful electrolyte, while plastic stick is for a few.

5.5 Preparation of electrolyte

5.5.1 Calculate the required gross of electrolyte according to its quantity for each single cell, calculate the required the required gross of KOH, LiOH and water according to Table 6.
5.5.2 Measure the required KOH and LiOH by platform balance.
5.5.3 Fill appropriate amount of pure water in the vessel first, then put KOH in it, and put LiOH in it at once, stir it continuously till it is completely dissolved, and then refill the required water, stir it evenly, and stand for cooling down.
5.5.4 When the electrolyte temperature falls to the room temperature, measure whether its consistency is in the required range by Densimeter. If it is lower, refill KOH in the electrolyte, and remeasure it after dissolving till it is qualified; if it is higher, refill water, and continuously measure it till it is qualified.
5.5.5 After standing for clarifying, take the supernatant for reservation.

5.6 Storage of electrolyte

The prepared electrolyte should be stored in the alkali-resistant vessels hermetically, preventing impurities entering into, if it is unused temporarily.

5.7 Notice

5.7.1 When preparing electrolyte, working clothes, glasses, rubber apron, rubber gloves and rubber overshoes must be worn. 5.7.2 There should be boric acid of 3% for reservation. When the electrolyte spills on the skin, clean it with boric acid at once; if the electrolyte spatters into eyes, clean it with plentiful clear water, and go to the doctor if it’s necessary.

6. Battery Stand Sizing

The battery stands are detachable design for easy installation

Dimensions of Battery stand
Diagrams
L(mm)=cell numbers per step× the cell length(l)+20 W(mm)= [the cell width(w)+15] ×2 H(mm)=the distance from the Min. electrolyte line to the top of cell terminal pillar +150+ the cell height(h)

1 tier -2 step battery stand Drawing

L(mm)= cell numbers per step × the cell length(l)+20 W(mm)=[ the cell width(w)+15] ×3 H(mm)= the distance from the Min. electrolyte line to the top of cell terminal pillar×2+150+ the cell height(h)

1 tier -3 step battery stand Drawing

L(mm)= cell numbers per step ×the cell length(l)+20 W(mm)=[ the cell width(w)+15] ×4 H(mm)= the distance from Min. electrolyte line to the top of the cell terminal pillar×3+150+ the cell height(h)

1 tier -4 step battery stand Drawing

 

Dimensions of Battery stands Diagrams
L(mm)= cell numbers per step× the cell length(l)+100
W(mm)=the cell width(w)+150
H(mm)= 500+the cell height(h)

2 tier -1 step battery stand Drawing

L(mm)= the cell numbers per step× cell length(l)+20
W(mm)=[the cell width(w)+15] ×2+100
H(mm)=[ the distance from Min. electrolyte line to the top of cell terminal pillar + the cell height(h)]×2+400

2 tier -2 step battery stand Drawing

L(mm)= the cell numbers per step× cell length(l)+20
W(mm)=[the cell width(w)+15] ×3+100
H(mm)=[ the distance from Min. electrolyte line to the top of cell terminal pillar×2+the cell height(h)]×2+400

2 tier -3 step battery stand Drawing

L(mm)= the cell numbers per step× cell length(l)+20
W(mm)=[the cell width(w)+15] ×4+100
H(mm)=[t the distance from Min. electrolyte line to the top of cell terminal pillar ×3+the cell height(h)]×2+400

Mark: The above battery stands drawings are only a part of Sunstone standard models, we could design and develop the steel battery stands according to end-users’ special requirements.