A very interesting subject. If I am not mistaken the HP CS battery backup supplies use a charger and post regulator/inverter. The charger is well designed but linear as I recall. I have one in the basement with 2 X 28 Amp hour SLA batteries. Purchased new. I screwed around with flea market duds. You get what you pay for as is always the case.
This has been working very nicely for years and the only thing I have had to do was change the battery set after 7 years. This sets now on year 2. However its somewhat of a power wasting unit and I suspect the discussion of this thread could result in a more efficient float charge method. The HP uses a transformer on the input. Regards Paul WB8TSL On Sun, Oct 26, 2014 at 7:30 PM, Bert Kehren via time-nuts < [email protected]> wrote: > Living in south Florida backup power is short term and long term. As lab > batteries I use T 105 also known as Golf Cart batteries. Costco has those 6 > Volt 200+A batteries for less than $ 80. Super price. Yes I have Costco > stock. For charging I use a VIctron Energy Phoenix 12 V 30 A charger. On > the > boat two 28 V 100 A chargers. No afilliation. > These people know what they are doing and if nothing else download info on > their chargers they know all about how to get maximum life and performance > out of batteries. You will find them in top end boats and RV's but the > bulk of their business is off grid power. If you have been on an African > Safari, the power most likely was Victron Energy. I think they still have > also a > very good application note. > A T 105 like battery if maintained is good for eight years plus. On golf > carts if used daily they typically last at least 4 years and I talk 70% > plus > discharge. > Bert Kehren Miami > > > In a message dated 10/26/2014 6:03:37 P.M. Eastern Daylight Time, > [email protected] writes: > > -------- > In message > <CAGVVbuFAM=u5Uhdf+wgTUNuoeMZ+=pzwq4jpugjnjdd60fg...@mail.gmail.com> > , Brian Lloyd writes: > > >> There are a variety of inexpensive wall-wart packaged float chargers > for > >> lead acid batteries around. Might be easier to just get something off > the > >> shelf. > > > >Some of these things are *extremely* noisy. > > Well, yes and no. > > It's amazing how much noise doesn't make it past the lead-acid battery > due to its low internal resistance. > > The real issue is not the chargers noise in float mode, where it is > barely loaded, but in bulk-charge mode, where it works full bore. > > Unless you want to burn a LOT of heat charging your batteries with > a linear regulator, you are better of shaving the noise after the > battery. > > For OCXO's, the 14.5-11.6V supply range is going to be much more > important than the noise from the charger. > > In other words, you will need some kind of regulation between > the battery and the OCXO, and that is where you should cope with > the noise. > > A couple of other concerns should worry you too: Isolation and > short-circuit current. > > The design I will suggest, is to find a good charger which takes > care of your battery, and have it do only that. > > Driving the load with the charger almost invariably means the > battery doesn't get optimal conditions which is why it will > croak in 5 years instead of the 20 years in the datasheet. > > Find another power supply for your load, at a voltage slightly > above the chargers bulk-mode (14.5 V) voltage, and use two > solid diodes to "or" the battery and the "production supply" > onto your "DC-bus". > > Don't skimp on the ATO fuses, put one right next to the battery. > > Your OCXO should be driven using a small isolated DC/DC converter > from this DC bus. > > It is important that the converter is isolated: It prevents > ground-loops, but it also allows you to common-mode filter the > supply to the OCXO to get rid of any noise from the DC/DC > converter. > > Yes, it is alot more complex, but the result is also much better. > > > -- > Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 > [email protected] | TCP/IP since RFC 956 > FreeBSD committer | BSD since 4.3-tahoe > Never attribute to malice what can adequately be explained by > incompetence. > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
