Thermal Runaway Warning signs and preventive actions Presented by - - PowerPoint PPT Presentation

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Warning signs and preventive actions

Presented by Peter DeMar

Thermal Runaway

Thermal runaway

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If thermal runaway does not scare you, then you are…

Thermal runaway

• Brand new to the stationary battery industry
• Ignorant of thermal runaway disasters

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Thermal runaway

• Someone who realizes there

are always warning signs

• Knows what they are
• Is applying the correct

preventive measures

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What is thermal runaway?

CAUSED BY

• Excess of battery

charging current

• Produces more internal

heat than the battery can dissipate

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Thermal runaway can be detected, prevented and recovered from

Recovery = green benefit

RECOVER a battery from thermal runaway and continue to use it

• Reduces carbon footprint for that

battery

• GREEN benefit for the

environment

• Good for your budget

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The monster appears unexpectedly?

“ It occurred

without warning ”

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The monster appears unexpectedly?

• There is ALWAYS an

early warning

• We just did not

understand the signals

• They are obvious
• There for many

months!

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What are these early warning signs?

• Increase in float current
• Starts very slowly
• Increases over time
• Current through the

battery

• Not necessarily =

charger meter

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What are these early warning signs?

• Increase in float current
• Starts very slowly
• Increases over time
• Current through the

battery

• Gradual increase in the

temperature differential between cells and ambient

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What are these early warning signs?

• Increase in float current
• Starts very slowly
• Increases over time
• Current through the

battery

• Gradual increase in the

temperature differential between cells and ambient

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These two items – when properly checked and tracked – will provide substantial warning so that you can take necessary actions to prevent a thermal runaway

What causes thermal runaway?

• Negative plate discharge

and sulfation

• Increase in float current
• Dry out of cells
• Loss of electrolyte contact

through AGM from plate to plate

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= inability of cells to dissipate internally generated excess heat

Preventing thermal runaway

• IEEE 1188 standard
• Maintain overall float voltage

correct for ambient temperature

• Track temp. differential

between cells and ambient monthly

• Track float current monthly

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Contact us for guidance on what “typical” float current should be for your battery

How to take the measurements

• Hand held meters
• Monitoring, such as the

BEM device

• Keep accurate records

and keep track of records

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Track readings for the life of the battery

Recovery after thermal runaway

• Re‐establish proper

saturation

• Remove sulfates from

the negative plates

• Install catalysts

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You can take a structurally intact battery from full‐blown thermal runaway and turn it back into a usable and reliable battery

Preventing thermal runaway

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• Re‐establish proper

saturation

• Remove sulfates from

the negative plates

• Install catalysts

You can prevent thermal runaway by applying these actions early

Who and what

• Now that the early warning signs of thermal

runaway are so easily observed, just who is responsible when it occurs?

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Who and what

• Now that the early warning signs of thermal

runaway are so easily observed, just who is responsible when it occurs? YOU ARE.

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Who and what

• Now that you understand that there is a means
• f recovering a battery from thermal runaway
• You can be pro‐active instead of re‐active
• You have time to determine just what actions are

best for you

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STATIONARY POWER SERVICES FOR INDUSTRY

a WBE Enterprise

(800) 221‐7123 www.batteryresearch.com Experts in DC Systems

a WBE Enterprise

(800) 221‐7123 www.batteryresearch.com

Corporate Headquarters Gary L. Brewer President 1313 County Route 1 Oswego, NY 13126 Toll‐Free: (800) 221‐7123 Phone: (315) 342‐2373 Fax: (315) 342‐0797

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Contact us today for more information

• n how we can help you!

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For further information please contact us.