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Information gathering before buying batteries

1. Determine the amount of energy the battery will deliver in its life using test procedures recognized by world wide manufacturers and published in the BCI technical manual. This information should be available from all manufacturers and should include:

  • Discharge current used (25Amps, 75Amps, 20 hour rate etc.)
  • Discharge time (Cycle Life) to an effective 100% depth of discharge (1.75 volts per cell)
  • Discharge cycles (Life Cycles) achieved before the battery could not deliver at least 50% of its original rated capacity

Note: Different types of batteries use test procedures that allow different end of life criteria. For example an electric vehicle or standard deep cycle product would be considered to be at its end of life when it was not able to deliver 50% of its rated capacity while a golf cart battery would not be determined to be at its end of life until it was not able to produce at least 1.75 volts per cell during 40 minutes of discharge at 75 amperes.

2. Determine the number of times the battery will have to be serviced in its life time as recommended by the manufacturer.

  • The manufacturers published battery life data will be the best achievable in the best of circumstances
  • You must use the manufacturers recommended service schedule
  • For time/cost analysis we recommend you use an average of 10 minutes per service per battery

3. Determine the average per hour/minute costs of service people in your organization

  • This number varies by region and industry and it should not include anything but direct labor costs
  • You can safely use a figure of $18.00 - $25.00 per hour ($.30 - $.42 per minute) without benefits
  • One transit authority stated that their direct labor cost associated with maintaining batteries in each of their transit buses was $180.00 per year; another stated it was as high as $550 per battery. We suggest using $22.00 as an average hourly cost ($.367 per minute).

4. Determine the cost of service materials over the life of the battery:

  • Distilled or specially treated water - using a per cell fluid usage by volume of 20% on an average cell volume of 2.35l/80oz and a 75% consumption efficiency or between $.02-$.04 per oz. Battery fluid volumes are as low as 5l/169oz and as high as 16l/540oz
  • Cleaning and neutralizing agents at 1oz per battery or $.25 per battery per service
  • Special clothing
  • Repair and replacement of battery boxes and trays and more

5. Cost per battery

  • Purchase price of the battery
  • Freight or handling charges (overland or can they be shipped via courier or air)
General Lead Acid Battery Description
General Lead Acid Battery Applications
General Lead Acid Battery Types
General Lead Acid Battery Chemistry
Discover® Sealed Valve Regulated Lead Acid Batteries
Discover® Deep Cycle AGM Battery
Discover®700 Series Dry Cell Battery
Discover® EV Traction Dry Cell Battery
General Benefits and Features of Discover Valve Regulated Lead Acid (VRLA) Technology
Sales Channels for Discover Battery Technologies
Things to question when making a battery buying decision
What to consider when buying a deep cycle battery
Information gathering before buying batteries
Calculating cost to own when purchasing batteries
Safety First
Safety and Productivity
When working with batteries
When handling battery acid
When installing or replacing batteries
When booster cables are used
Danger of exploding batteries
Warning and warning labels
Parallel connections for sophisticated users and installers
Parallel connections for unsophisticated users and installers
Charging
When charging batteries
Selecting a charger
General charging information for AGM and GEL batteries
GEL battery charging
AGM battery charging
Equalizing (Flooded batteries only)
Discharging
Typical self-discharge of VRLA batteries at different temperatures
Typical self-discharge of high quality deep cycle flooded batteries at different temperatures
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Can I use all of my normal 120/240 VAC appliances?
What components do I need for a grid-tie system?
What components do I need for a complete solar system?
What type of solar module mounting structure should I use?
Where should I mount the solar modules and what direction should I face them?
Should I set my system’s battery bank up at 12, 24 or 48 VDC?
Should I wire my home for AC or DC loads?
Can I use PV to heat water or for space heating?
How do solar panels (cells) generate electricity?
Will solar work in my location?
Tables & Figures