Regeneration cost:

20—30 % from price of a new battery

Lifetime exhaustion

RECYCLING

RELEVANCE OF THE PROBLEM

Mobile TeleSystems OJSC exploits a lot of

sealed lead-acid

accumulator batteries Necessary to renew: up to 10% per year

Cost of replacement for one Accumulator(12 V, 90 A*h):

15—20 thous. rub.

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Other defects• electrode corrosion (+);• damage of contact layer;• evaporation of water and/or acid;• short circuit

up to 20%

Sulphation: more than 80%

of batteries should be replaced

Reason of failure

May be

regeneratedup to ratings

3240 rub.

LEAD-ACID ACCUMULATOR:HOW DOES IT WORK

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PbO2

Positive electrode: lead dioxide

FULLY CHARGED ACCUMULATOR

DISCHARGEDACCUMULATOR

PbNegative electrode:

spongy lead

H2O + H2SO4

Electrolyte: sulfuric acid solution

PbSO4

Positive electrode: lead sulfate

PbSO4

Negative electrode: lead sulfate

H2O + H2SO4

Electrolyte: less acid, more water

MAIN PHYSICO-CHEMICAL PROCESSESIN LEAD-ACID ACCUMULATOR

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Accumulator discharge results in formation of a lead sulfate layer of fine-pored structure on both electrodes, and the strength of sulfuric acid in electrolyte solution diminishes. During accumulator charge the sulfate dissolves and then deoxidizes till metal lead on the negative and till lead oxide on positive electrode, and acid strength grows.

per one cell

MAJOR DEGRADATION CAUSE FOR LEAD-ACID ACCUMULATOR CHARACTERISTICS: SULPHATION

of negative and positive electrodes

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Degradation of accumulator plates due to sulphation

SWEL Energy Ltd. has worked out an innovative technology for desulphation and regeneration of battery performance during its electrical charge

Partial sulphation

Deep sulphation

Very deep sulphation

REGENERATION TECHNOLOGY and PROCEDURE

Internal resistance of lead-acid accumulator : Active r. — depends upon accumulator structure and its charge condition — cannot be reduced Polarization r. — is determined by electrochemical processes in the accumulator — can be reduced

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Oscilloscope traces for charging voltage and current

Voltage

CurrentMinimal internal

resistance

SWEL Energy Ltd. has worked out an algorithm of accumulator charge by small energy ‘portions’, that provides separation in time of electrical and chemical processes.

As a result the polarization component of accumulator internal resistance declines almost to zero.

Regeneration algorithm provides optimal speed of sulfate dissolution and accumulator charge at

minimal internal resistance

PRACTICAL APPLICATION EXPERIENCE PresentationPage 6

During the last two years SWEL Energy Ltd. has successfully executed a number of projects on performance regeneration of lead-acid accumulators of different manufacturers.1. Under contract with Rostelecom OJSC we regenerated accumulator batteries for 3 exchange stations: • “Gorky-10» in Moscow region, Odintsovsky microdistrict, Gorky-10 settlement, 31

(Sonnenschein A412/50 A batteries);• Switching substation-597 “Maliye Vyazyomy” in Moscow region, Odintsovsky microdistrict, Maliye

Vyazyomy settlement, Petrovskoye highway, 3а (Oerlikon COMPACT-POWER 12CP50 batteries);• Non-commercial partnership of gardeners “Droujba” in Moscow region, Odintsovsky microdistrict,

Zhavoronky settlement (Oerlikon COMPACT-POWER I 2CP50 batteries).All accumulators have been functioning nominally during 20 months (since April 2013).

2. Under contract with Rostelecom OJSC branch in Novgorod we regenerated Delta accumulators (50 Ah). All batteries have been functioning nominally during 8 months (since 2014).3. Under contract with MGTS OJSC we regenerated Sonnenschein accumulators (65 Ah) for one exchange

station. All batteries have been functioning nominally during 1 year (since November 2013).4. Under contract with Ecomotors Ltd. we regenerated Sonnenschein and Tudor UPS 12V360 batteries (88 Ah). All batteries have been functioning nominally in cyclic operation (30—50% discharge) during 2 years (since

December 2012). Since May 2014 a part of batteries has been functioning in off-nominal traction mode (100% charge/discharge cycle) providing charge-discharge ratings.

5. Under contract with Cleanford Ltd. (Moscow region, Krasnogorsk) we regenerated Sonnenschein accumulators (2V/225 Ah).

During 10 months (since February 2014) all batteries have been functioning daily as normal with 100% discharge, providing charge-discharge ratings.

Regeneration of accumulator batteries TUDOR UPS 12V360 under contract with Mobile TeleSystems OJSC

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In October-November 2014 SWEL Energy Ltd. regenerated 198 batteries Tudor UPS12V360 under contract with Mobile TeleSystems OJSC, which Mobile TeleSystems OJSC had used for 8 years as part of uninterruptible power systems.

Voltage ‘sag’

It was identified that during operation all batteries had been more or less subjected to sulphation (huge voltage ‘sag’ during discharge, decrease of discharge capacity in comparison with nameplate capacity).

After processing and regeneration the accumulators demonstrated charge-discharge characteristics generally equivalent to nameplate values.

Regeneration of accumulator batteries TUDOR UPS 12V360 under contract with Mobile TeleSystems OJSC

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After regeneration all regenerated batteries were tested in 15-minute discharge mode. Consequently, 18 batteries were considered defective that amounted to 9% of the total number of batteries, delivered for regeneration. Such defective ratio should be considered as very low.

After regeneration 91% of batteries were recognized usable for further operation;

The technology worked out by SWEL Energy Ltd., is very likely to provide complete regeneration of work capacity for accumulators suffered from deep sulphation.

Regenerated batteries display nameplate characteristics during discharge by small, medium and high current;

LIFE TESTS PresentationPage 9

In 2012—2013 SWEL Energy Ltd. carried out life tests of regenerated accumulators with its discharge by heavy current 3С (depth of discharge 30%). As shown on the figure, the lifetime of batteries regenerated with the help of SWEL Energy Ltd. technology, corresponds to ratings delivered by battery manufacturers.

Test results

Average values

Initial capacity

Measured capacity (% to initial discharge capecity)