HI Tom, Are you saying that you are seeing 14 years on a single string of L-16's? If so I would like to hear your charging recommendations.
thanks, jay peltz power On Jun 30, 2010, at 9:32 AM, The Office of Tom Duffy wrote: > Bob > > Yes the problem is hard sulfation due to chronically under charging. The > absorb time and voltage is the most critical charge mode for charging > batteries. The default settings on inverters and charge controllers are > always way too short, so they hold the batteries in absorb for a little > while, then go to float, leaving the batteries under charged forever, thus we > get hard sulfation. This is what you have here. Typically two parallel > strings will yield about 6 ½ years of life in a system that is used off grid. > While a single series string will yield 10 to 14 years (properly maintained) > 14 years is not the rule however. > > A bit of due diligence is now required to get these back, (and they may not > be worth it). Separate the two strings and give them 62 volts for 10 hours; > you’ll have to watch them so they don’t get too hot. Set the absorb settings > below and give them about three weeks. If there is some improvement in > capacity, another EQ; 61 volts for two hours may just do it. > > With the Magnum 48 volt inverter I calculate the absorb time at 5 hours, now > typically the absorb charge should be about 58.8 volts but, most batteries > die because of under charge so I would set the absorb voltage at 59.4. You > may have to update the software for the Magnum control panel to get more > programming flexibility. > > The MX60 with 6 of the 175s should be set to absorb for as long as possible, > I think the last software version allows 4 hours. I calculated absorb time > with this setup is 19.6 hours which is not possible, so just keep the > controller from going to float for as long as you can. > > Concord makes a real nice 915 AH 2 volt cell which should give a decade plus > life, for the next bank. I would avoid parallel strings at all cost. If you > feel this is too large a bank then use the 660 AH 2 volt. You can always call > me 575-539-2111 if you have questions. I have been in the battery business > almost 45 years. > > Tom Duffy > Systems Design Engineer > > [email protected] > 575-539-2111 X 301 > Although no trees were killed in the sending of this message, a large number > of electrons were terribly inconvenienced. >
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