Industrial deep cycle batteries Sometimes called "fork lift", "traction" or "stationary" batteries, are used where power is needed over a longer period of time, and are designed to be "deep cycled", or discharged down as low as 20% of full charge (80% DOD, or Depth of Discharge). These are often called traction batteries because of their widespread use in forklifts, golf carts, and floor sweepers (from which we get the "GC" and "FS" series of battery sizes). Deep cycle batteries have much thicker plates than automotive batteries.
Plate Thickness Plate thickness (of the Positive plate) matters because of a factor called "positive grid corrosion". This ranks among the top 3 reasons for battery failure. The positive (+) plate is what gets eaten away gradually over time, so eventually there is nothing left - it all falls to the bottom as sediment. Thicker plates are directly related to longer life, so other things being equal, the battery with the thickest plates will last the longest. Automotive batteries typically have plates about .040" (40/1000") thick, while forklift batteries may have plates more than 1/4" (.265" for example in the Rolls-Surrette) thick - almost 7 times as thick as auto batteries. The typical golf cart will have plates that are around .07 to .11" thick. The Concorde AGM's are .115", The Rolls-Surrette L-16 type (CH460) is .150", and the US Battery and Trojan L-16 types are .090". Most industrial deep-cycle batteries use Lead-Antimony plates rather than the Lead-Calcium used in AGM or gelled deep-cycle batteries. The Antimony increases plate life and strength, but increases gassing and water loss. This is why most industrial batteries have to be checked often for water level if you do not have Hydrocaps. The self discharge of batteries with Lead-Antimony plates can be high - as much as 1% per day on an older battery. A new AGM typically self-discharges at about 1-2% per month, while an old one may be as much as 2% per week. http://www.windsun.com/Batteries/Battery_FAQ.htm#What is a Battery? cut and paste -- is broken. is a battery is part of addr. http://www.windsun.com/Batteries/Battery_FAQ_Index.htm Kirk -----Original Message----- From: Christopher Witmer [mailto:[EMAIL PROTECTED] Sent: Thursday, August 15, 2002 3:53 PM To: biofuel@yahoogroups.com Subject: Re: [biofuel] Please help me think through this decision Ken, the battery is of the AGM type, so it does qualify in the broad sense as lead-acid although it isn't flooded. I'm no expert on batteries by any means, but I figure if it gets recharged when it drops down to 80%, it should do fine . . . no? Christopher Witmer Tokyo Ken Provost wrote: > Chris writes: > > >>Folks, please help me think. >> >>I have access to the following at "fire sale" (90% off list) prices: >> >>1. A nearly new four pole (slow rotation) 12.5kWh diesel generator that >>can be fully user maintained. >> >>2. A MONSTER of a brand new 24V forklift battery -- the thing weighs >>nearly 7000 pounds (about 3000 kg) and will last more than 20 years if >>properly handled. >> > > Sheesh, Chris, what's to think about? Grab 'em quick, even if you > don't know what to do with them yet. BTW, what chemistry is that > battery? If lead-acid, be careful about pulling a lot of current > (even the supposedly rated amount) out of it, if you really hope for > 20 years of life. ------------------------ Yahoo! Groups Sponsor ---------------------~--> 4 DVDs Free +s&p Join Now http://us.click.yahoo.com/pt6YBB/NXiEAA/RN.GAA/FGYolB/TM ---------------------------------------------------------------------~-> Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuels list archives: http://archive.nnytech.net/ Please do NOT send Unsubscribe messages to the list address. To unsubscribe, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
