If anybody is looking to buy a standalone AC-fed, triple-stage lead acid charge controller, I recommend Iota:
DLS series with the IQ4 module: http://www.iotaengineering.com/dls.htm http://www.iotaengineering.com/iq.htm It is worth noting that any large off-grid (solar, mostly) triple stage charge controller will also have a temperature sensor cable. You're expected to put a small temperature sensor in the center of your lead acid battery string so that the charge controller can compensate accordingly. Whether wet cell or AGM lead acid batteries behave very differently at temperatures of 2C vs 22C. On Wed, Mar 9, 2016 at 3:11 PM, Forrest Christian (List Account) < [email protected]> wrote: > That's not 100% correct... > > What isn't known very well is that there are lead acid batteries which are > designed for 'standby' or 'flat' use, and lead acid batteries which are > designed for 'cyclic' use. (And of course some hybrids out there which can > do both at least somewhat). > > 'Standby' would be the method you'd use at most AC power sites. The > battery rarely gets cycled, and you're mainly concerned with service life > in years. In this application the best (and manufacturer recommended) > method of charging the batteries is to apply a constant voltage across the > battery with a current limited to about 0.1C. For an 80Ah battery, this > means a 8 amp charge limit. > > Cyclic use is where you expect to discharge and recharge the battery > regularly, like at a solar or other off-grid site. For these, you really > want to do a multi-stage charger mainly to fully top off the battery. > > Using the wrong charge method for your application *will* shorten your > battery life. > > Just for an example: > > The following is an example of a small standby multipurpose battery > datasheet: http://www.brooksequipment.com/files/ps-1270.pdf If you > note in the datasheet, it indicates for standby use, you should float it. > It also explains how to charge in cyclic applications as well. But if > you look at the life characteristics, you're going to destroy this battery > if you cycle it a lot... Even a 30% daily discharge will result in a > lifetime of around 3 years or less, depending on your choice of when to > retire the battery. > > > > On Wed, Mar 9, 2016 at 12:52 PM, Bill Prince <[email protected]> wrote: > >> You can keep batteries at their float potential with a regulated power >> supply, but it won't really "charge" them. The point is that to keep >> batteries in their best condition, you really should do a bulk charge after >> a discharge event. The power supply solution won't do that. >> >> A UPS has a separate connection for the load and the batteries so that it >> can discriminate between current going to the batteries versus current >> going to the load. A power supply can not do that. >> >> Also, many UPSes will have a low voltage disconnect (LVD). This is a bit >> of a philosophical issue, as some people will rather run the batteries down >> to avoid any downtime. My opinion is that if your battery array is large >> enough, you should never hit LVD. Stuff happens though, and batteries are >> usually the most expensive component of a backup system. >> >> bp >> <part15sbs{at}gmail{dot}com> >> >> >> On 3/9/2016 11:38 AM, Mathew Howard wrote: >> >> Is there really any advantage to using something like an AD-155B with a >> UPS function over just connecting the batteries in parallel with the load >> to a normal DC power supply and setting the voltage properly? It seems like >> there would be less parts to fail and it'd be easier to add redundancy if >> the batteries were just connected in parallel. >> >> On Wed, Mar 9, 2016 at 12:52 PM, Chuck McCown <[email protected]> wrote: >> >>> A pair of power supplies that are capable of pulling the load and >>> charging the battery. >>> >>> For example, if you needed 200 watts for your 24 volt loads, you need >>> 8.3 amps. Round that up to 10 amps. >>> Then you have to decide how long you want this thing to last without >>> commercial power. I would think 24 hours is a minimum. So 10 amps x 24 >>> hours is 240 amp hours of battery. >>> It is always a safe figure to charge a battery at .1C or 10% of its >>> capacity or less. That would be 24 amps to charge the batts after a power >>> outage, plus 10 for load = 34 amps of power supply. You could get by with >>> 20 amps, just will take a bit longer to charge. >>> >>> Lots of 20 amp 28VDC power supplies out there. >>> Rule of thumb double your load power or more to size the charger. >>> >>> *From:* SmarterBroadband <[email protected]> >>> *Sent:* Wednesday, March 09, 2016 11:45 AM >>> *To:* [email protected] >>> *Subject:* [AFMUG] Small DC Site >>> >>> >>> What are people using to power small DC sites. Option 1 up to 150 - 200 >>> Watts, option 2 up to 300 – 400 Watts. I’m looking for a DC UPS that can >>> charge attached batteries. Need to have 24 and 48 volt. >>> >> >> >> > > > -- > *Forrest Christian* *CEO**, PacketFlux Technologies, Inc.* > Tel: 406-449-3345 | Address: 3577 Countryside Road, Helena, MT 59602 > [email protected] | http://www.packetflux.com > <http://www.linkedin.com/in/fwchristian> <http://facebook.com/packetflux> > <http://twitter.com/@packetflux> > >
