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Post by fishfever on Mar 2, 2010 18:10:33 GMT -5
Carl, that's a clever idea for the battery powered pump. There are a number of inexpensive ways to keep the tank going enough to avoid major problems after an outage. I feel very comfortable with my Vitalife 200 HOB running normally through a lengthy outage but this is just one approach that works well (or will work well) for me. I'm very glad I invested in the UV sterilizer; even though I don't have expensive fish (probably paid less than $100 for all of them) we have become quite attached to many of them. With this hobby, the sum of many small improvements can pay big dividends in terms of a healthier tank. I look at the emergency backup power, UV sterilizer, Wonder shells, extensive aeration, superior/redundant filtering, etc. all being a part of the equation that promotes better fish health...
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Post by Carl on Mar 2, 2010 19:23:50 GMT -5
I'm very glad I invested in the UV sterilizer; even though I don't have expensive fish (probably paid less than $100 for all of them) we have become quite attached to many of them. With this hobby, the sum of many small improvements can pay big dividends in terms of a healthier tank. I look at the emergency backup power, UV sterilizer, Wonder shells, extensive aeration, superior/redundant filtering, etc. all being a part of the equation that promotes better fish health... Your last statement is where I often feel I am banging my head against a wall. I try and drive these points home in my Aquarium Disease Prevention Article , emails, and when I used to frequent other fish forums (I often was flamed for making such a statement in other forums). I appreciate your making this point, as I do not feel quite as alone in my agreement. Carl
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Post by fishfever on Mar 6, 2010 13:56:17 GMT -5
I finished testing the latest inverter and results were quite good. Although this inverter also did not meet the specs for standby current, it was only about 30% worse (versus 300% for the other, gradually dropping to 200% as it warmed up). It may be there is variance from unit to unit but even with this one not meeting spec, it still gave me decent run times due to good low-end efficiency. My Vitalife 200 HOB ran for about 14 hours and the Whisper 10 air pump ran for over 50 hours from the same 7AH battery that gave me about 1 hour run time in the UPS.
So now it's on to construction. My thoughts are to make it easily accessible, easy to construct and not to take up much valuable space under the stand. The door already has two holes up high (not drilled all the way through), probably to mount some accessory basket. I'll probably just hang a wire frame basket or plastic basket there which can hold the battery, inverter (and possibly the charger/power supply although it might just sit on the stand floor with the UV sterilizer power supply).
Although I will likely use relays to automatically switch the inverter in/out later on, my first version will be quite simple and the inverter will run the HOB filter all the time, even when power is not lost. The charger will have to supply enough current to float charge the battery and power the inverter/filter. The reason I want this simplified setup is I want to make sure the inverter is going to be reliable so I would prefer it to run 24/7 at first (for at least a few months). I'll need to attach an audible alarm as well in case the inverter is not reliable and it fails. When I reconfigure everything later on for inverter switching this alarm will go off when the battery is exhausted (~14 hours for HOB or 50+ hours for air pump). If I am home and we get this long of an outage I can pop in a new battery (pulled out of one of my spare UPS) and keep running for another extended period.
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Post by fishfever on Mar 13, 2010 14:25:56 GMT -5
I have finished putting together my emergency power unit and installed it in the tank today. I have run many cycles and quite satisfied that everything is working as it should with full unattended backup power and recovery should we lose power while away on a trip or vacation. I did try the very simple battery/charger/inverter wiring connection but there some big drawbacks to this scheme. First the battery charger (which needs to be a "smart" or "staged" charger to avoid overcharging the lead-acid battery) is fooled when the inverter/load is also connected. The charge time goes up greatly and the charger doesn't behave well (hard to explain without getting real technical) which makes me believe it could shorten battery life by never going to a "float" charging mode. In addition, the inverter will not restart when the power is restored until it is reset by disconnecting the battery (which is not completely dead but measures around 10.5 volts). So this would mean somebody would have to be present when power is restored to reset or else the filter wouldn't run even with normal power available. I was only planning to use this wiring scheme temporarily to check inverter reliability by running 24/7 for a while but after seeing these issues I went straight to my final scheme which has automatic switching circuits to overcome these problems. I have run many cycles and haven't noticed any issues. I'll probably continue running cycles for awhile more although I'm starting to get sick of testing! The switchovers (both from normal to emergency and emergency back to normal) occur almost instantaneously and I notice no break at all in the water flow from my Vitalife 200 HOB. I ordered a 7AH battery to replace the one I had been borrowing from my UPS but the battery company sent me a 9AH instead. It is physically the same size but weighs about 1.5 lbs heavier. With this battery I'm getting over 16 hours run time on the Vitalife 200 and probably over 60 hours with the small Whisper 10 air pump (but I have not bothered to verify the 60+ number). Here is a picture of the backup unit ready to install: i558.photobucket.com/albums/ss25/fishfever/Emergencypowerunitreadytoinstallint.jpgThe total weight is 9 lbs which is significantly lighter than the 30 lb UPS that it is replacing. I bought the base from a local Goodwill store for a whole $2! Since I had most of the small electrical items in my junk box, I probably paid about $75 for everything. I imagine with careful shopping one could put it together for about $100 from scratch not including labor cost of course. (Note: I was trying more for functionality than looks. LOL) And here it is installed (vertically to save space): i558.photobucket.com/albums/ss25/fishfever/Emergencypowerunitinstalledintank.jpgIt only uses about a 5" x 5" corner space so I have regained a good bit of tank stand floor space by replacing the bulky inverter (and more than quadrupled the emergency run time as well). My next project will be to clean up the ugly cable mess by mounting the power strip up high off the floor which will give me even more space for food, maintenance items, etc. I also plan on adding an audible alarm so that in the unlikely event we get a power interruption of more than 16 hours I can replace the battery with a fresh one (probably a 7AH from one of my spare UPS's). By the way I don't know if anyone else noticed this, but in IE8 there is no "Quick Reply" box to post messages so I'm using Google Chrome (which I normally use) but apparently there is some html code not recognized by IE8 here.
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Post by Carl on Mar 14, 2010 10:39:42 GMT -5
That is very compact compared to the system I used with two series 24 (85 AH). Is there a way to add a switch that stays open while A/C is operational? I used a standard charger that ceased charging when the batteries were "full", can this be incorporated (probably too bulky)? Anyway, this is a really neat idea and should solve most problems. BTW, I am seeing the quick reply box in both IE8 and Firefox (I have not tried Chrome, I try to not use any Google products I do not have to when other alternatives are available, although I admittedly use Google Docs for business) Carl
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Post by fishfever on Mar 14, 2010 12:26:50 GMT -5
Carl, essentially I'm doing this with a relay. The charger I'm using is a smart 3-stage type which tries to put max amps when the battery is fully exhausted. Then as the battery voltage rises toward the gassing point, the current gradually decreases. Once the battery has reached the charged state as indicated by the drop in current and certain terminal voltage (varies a little with ambient temperature) it switches to a trickle charge mode to maintain the battery. However, with the very simplistic wiring scheme where the inverter runs all the time the inverter/load drains current from the charger which totally throws off the "smarts" in the charger. I was able to get away with this with the Whisper 10 since it draws so little current, but the Vitalife 200 was drawing about 2/3 of the charging current so the battery charger "thought" the battery wasn't reaching a charged state since too much current was being drawn even when the battery was actually charged and the battery was actually still being "forced" to draw a much higher current than the normal trickle charge... which led me to believe long term the battery life would be shortened (I expect 3-5 years lifetime at least since most of the time the battery is simply being maintained with once in a blue moon partial draw downs). If your dedicated battery is going to be sitting idle for a very lengthy time and it is not known when it will be needed (which for emergency backup use it's the norm) then you are going to want to float the battery with some kind of charge to make sure it will have maximum capacity when you need it. The system I'm using accomplishes this and also isolates the charger from the inverter and load.
The switch you see on top of the blue box simply shuts off the ac power for everything for maintenance or testing (I use it to simulate power outages). But I really need to unplug the filter when I clean the tank because the battery would keep the filter running for another 16+ hours now... ;-)
The IE8 thing is probably a cookies issue since I just checked and it isn't logging me in for some reason. Doesn't matter though, since I rarely use IE8 anyway now.
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Post by Carl on Mar 14, 2010 14:38:10 GMT -5
Could you make this run on A/C when power is available (using a relay), then only switch back to DC/Inverter when power is cut. When power is restored the relay would open and switch back to A/C.? This would seem to removed the charging problem and allow a float/trickle charge when idle?
Have you tried Firefox to see how it works? I know many (including Steven who works with me) prefer Firefox.
Admittedly I have never even tried Chrome, but then I have found either Firefox or IE to meet all my needs (including templates), and since Google has been allowing plagiarism of my articles for profit and is not responding to YouTube complaints I have made about stalking/cyberbullying of my daughter (that often leaves her a "mess"), I try and have as little to do with Google as possible such as removal of most of my Google Ads(sorry to get off subject a little).
Carl
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Post by fishfever on Mar 14, 2010 21:52:28 GMT -5
Sorry if I was unclear with all my babbling Carl. The problems I experienced were with direction connections from the charger to battery to inverter. Once I put the relay switching circuits in (as in the constructed unit shown in the pictures) it solved these issues. I was trying to make it clear (as mud) of the problems encountered without employing switching in case anyone else wanted to go down this path.
It would actually be possible (and I already did a paper design using a spare laptop power supply) to make a custom charger to compensate for the extra load on the battery with the direct connection approach. Basically you want to be able to vary the current threshold at which the charger switches to trickle charging mode which would be the sum of the desired battery current at the switching point plus the load. For example if 200mA is the desired battery current threshold and the load (inverter plus filter) is 300mA, you would tweak the battery charger to switch at 500mA instead of 200mA. Unfortunately most commercial chargers do not have the ability to dial this in (understandably) since they were designed only to charge the battery and not perform as power supplies also. But you'd still have to deal with the inverter reset after regular power comes back so this only solves one of the two gotchas anyway without adding extra circuitry... and so if I have to add extra components I might as well automatically switch back and forth from household mains and inverter, exactly as you stated and as was implemented.
Yes I also have Firefox (and even Safari) but have found Chrome to be the fastest so far in general (IE8 easily being the slowest) although Firefox is not too far behind Chrome. Safari seems to hang and crash frequently so I rarely use it. Chrome's popup blocker doesn't work as well as the add-in I have in Firefox so each seems to have it's strengths and weaknesses.
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