DIY Universal Battery Backup For Your Reef

[chipmunkofdoom2]

Thanks for a very informative article, chipmonkofdoo m2! This has always been a huge concern of mine. Frankly, I'm surprised someone or some company hasn't come out with a product for us reefers. I'm sure folks would scoop it up! I would actually like to see something that would kick on when I'm not home. When I'm on vacation, for instance. Something other than an expensive backup generator. Good job!

Thanks Cool Fish

A few companies like Ecotech have tried (with their battery backups for their DC pumps). The trouble with battery backup is each aquarium is so different that there's no one "way" or "system" that manufacturers can target. In other words, it's just something that's really tricky to do.

If you're looking for a low hassle way of doing something like this, an inverter/charger would work. Basically, this is everything I describe in my system, but it requires no assembly. You simply hook up a battery and you're good to go. When the power is on, the device charges the battery and supplies utility power to the output. When the power fails, the device draws current from the battery and supplies it to the output. When the power comes back on, the device begins supplying utility power again and automatically recharges the battery.

These devices work and for some they might be the right choice because of their low complexity. They're not my favorite solution though. First, if any one part in the system fails (the charger, the transfer switch, the inverter, any of the other miscelaneous electronics, etc), the device is a brick. If you're inside warranty you may get it fixed. If not, you're trashing the whole thing and buying a new one. Second, these devices don't specify how they charge the battery. They don't specify whether they use a multi-stage charge or just float the battery. This is becomes more important the more battery capacity you have. Lead acid batteries can experience significantly shorter lives if they sulfate or if they're not charged properly. If you bought a cheap $70 battery to get you through short outages, maybe this doesn't matter. If you bought 5kWh of backup power at almost $700, this is a big deal. Third, the capacity is fixed. You're stuck with just 700W of power (for the one I linked). If you want to power more with it, you can't just buy a better inverter. You need to buy a whole new inverter/charger, and they're not exactly cheap.

I admit, I'm a bit of a perfectionist. It's likely that an inverter/charger would likely be a pretty good solution for most reefers. I just prefer things to be modular, repairable, and upgradable, and inverter/chargers don't fit this description.

 

[chipmunkofdoom2]

Very well done sir. Thank you for putting that all together. This may very well save someones tank in the near future. I have two APC computer battery back up boxes connected only to a critical intank flow device in each tank. I also have an old ECOTEC battery back up box I intent to cut apart and utilize a larger battery to back up my ecotec pumps because they can utilize 12 volt circuits very simply. You have resparked my interest in this project.
Folks should also consider the usable life of there battery is 4-6 years and should put it on a replacement schedule and possiblly keep it inside a small plastic vented tub. I have seen a hand full of old batteries on trickle chargers go a bit haywire when they fully melt down. Usually only over working the trickle charger. But its not to hard to set in into something to stop any splits if a battery case splits then the plates fail inside eventually.

Battery safety is definitely something to consider. AGM batteries are a lot safer than the old fashioned lead plate marine deep cycles. It's not that AGM batteries can't fail, they just tend to do so less catastrophically. They also don't release any gas when charging, which is a must if you're going to have them inside.

While AGM batteries don't last forever, they do have relatively long service lives. In applications like ours, where they may only get discharged once a year, I wouldn't be surprised if you could get 8 years out of them easily. Only getting discharged once every few months and being on a battery maintainer the rest of the time is a relatively easy life for a battery. Once you get close to the 8 - 10 year mark, I'd definitely consider replacing them. Sooner if you discharge them frequently.

 

[kenle74]

What do you guys think of this generator:

https://www.ebay.com/itm/311668175923?afepn=5337259887&rmvSB=true

Seems really cheap at $499.

 

[chipmunkofdoom2]

What do you guys think of this generator:

https://www.ebay.com/itm/311668175923?afepn=5337259887&rmvSB=true

Seems really cheap at $499.

I don't know much about generators, sorry I have relatively little experience with them. I do know that higher quality generators (Honda, Yamaha, Briggs and Stratton) are much more expensive than that. A 1,000W Honda generator costs close to a thousand dollars. I'd be cautious of a generator that costs as little as that, claims to output 10x more, and has many more hookups/features. In the context of our discussion here, your emergency power solution is your tank's safety net. It absolutely has to work when you need it to, full stop. I would not personally attempt to cut corners on something so important.

But, that's just me, and I admittedly don't know much about generators. Perhaps someone with more generator knowledge could answer your question.

 

[doughboy]

how long does it take to fully charge the 100ah battery say if hooked up to a car like what you described.

 

[doughboy]

found this on amazon for $140.
This might be a cleaner/better/preferable solution for most people. Its basically everything in the diy packed together in a nice case. equivalent to 42ah battery capacity. uses lithium ion battery instead of sealed lead acid (SLA) battery so is more compact. built in charger and inverter.

https://www.amazon.com/Webetop-Port...pID=51GgsXNwHLL&preST=_SY300_QL70_&dpSrc=srch

60ah version for $200
https://www.amazon.com/dp/B076J65N4...169e193bb59&ref_=pd_luc_rh_sbs_03_04_t_img_lh

 

[DSmithZ28]

Is your question about the mechanism that does the transfer? If so, check out this transfer switch. It requires a bit of wiring, but basically there are two inputs, one from your inverter (which draws power from your battery) and the other from the wall. When the utility power is on, the transfer switch sends power from the utility to the output. When the utility power fails, it switches over to the inverter automatically. When the power comes back on, it switches back over again.

Or was your question about how to run your return pump, and only your return pump, if your Jebao is plugged into your Reef Keeper?

No I think you nailed my question in the first part. I am never home when disaster happens and I need an automated backup system to power at least mt return pump. I will read that link you sent and see if I can better understand it. Thanks for the help!

 

[chipmunkofdoom2]

found this on amazon for $140.
This might be a cleaner/better/preferable solution for most people. Its basically everything in the diy packed together in a nice case. equivalent to 42ah battery capacity. built in charger and inverter.

https://www.amazon.com/Webetop-Port...pID=51GgsXNwHLL&preST=_SY300_QL70_&dpSrc=srch

The stated capacity of 42,000 mAh (42 Ah) is not inaccurate, but without context it is meaningless. This device likely contains lithium ion cells (probably a commodity cell like a 18650). These cells individually are 3.7V. Watt hours can be obtained by multiplying capacity by voltage, so in this case, it would be 42 Ah x 3.7V, which is 155.4 Wh. The unit says this is about what it can supply (note how it says 155wh on the side). 155Wh isn't bad, but it's a little expensive for what you're getting. A 100Ah AGM battery is $165, but it contains about 1,200 Wh of power. This works out to be about 7.27 Wh per dollar. This device, by contrast, provides just 155 Wh and costs $140, which is about 1.11 Wh per dollar. True, you need much more than just the battery, so this analysis is a bit primitive, but my point is that you're not getting very much for your money with this device. I'm not even sure this device can automatically power your aquarium loads without you manually hook it up, which is a big problem if you're not home and you lose power. An inverter/charger is a better option if the DIY route is not for you. It's more expensive and you need to provide a battery for it to work, but it has more capacity and it's automatic.

 

[siggy]

What do you guys think of this generator:

https://www.ebay.com/itm/311668175923?afepn=5337259887&rmvSB=true

Seems really cheap at $499.

I have had a few generators over the years, nice ones, cheap ones . If it sounds too good it generally is. those seldom last 3-5 years before they let you down and you runout and grag what's left during an outage. I currently own 2, 1 Is a home depot off brand I grabbed during an outage:mad: . But the best 1K I ever spent is my little Honda, always there when i need it!

 

[chipmunkofdoom2]

how long does it take to fully charge the 100ah battery say if hooked up to a car like what you described.

It depends on the car and how much extra capacity the alternator can supply. I tried to calculate this last time my power was out, but could only get ballpark numbers at best. If you assume that your car can provide 5 spare amps at idle and that all of this extra energy goes into your battery, a 100 Ah battery would take about 20 hours to charge. If your car has 10 extra amps, that's 10 hours. 20 extra amps is 5 hours, and so on. It's unlikely that your car will have this much spare energy available from the alternator though (auto gurus, feel free to chime in if this is not correct).

Another option if power is out long term is to start your car, then attach your inverter directly to your positive/negative terminals on your car's battery. This requires that you have a safe place to leave your car running and that you can run electrical cords inside your house. But, you don't have to wait for the battery to recharge.

I'm unable to run a generator, so I have two batteries, a 50Ah and a 100Ah. If my power goes out again, my 50Ah is hooked up to the system and will drain first. Once that's empty, I will hook up the 100Ah and look for a way to charge the 50Ah. I have a 6 amp charger, so if I can find someone with power, the 50Ah battery will be charged in less than 10 hours. After it's charged, I'll wait for the 100Ah battery to be discharged, swap it out, and repeat. If I can't find someone with power who will let me charge my batteries, I'll charge them with my car. Not the best option, but certainly an option.

 

[chipmunkofdoom2]

No I think you nailed my question in the first part. I am never home when disaster happens and I need an automated backup system to power at least mt return pump. I will read that link you sent and see if I can better understand it. Thanks for the help!

No trouble. If the DIY is a bit off-putting, an inverter/charger will do the same thing the system I describe does. They're just a bit more expensive and less repairable. But, they're pretty simple. Buy the unit, buy a battery, plug everything in and you're good to go.

 

[Turbo's Aquatics]

Fantastic...another thread I have to read fully someday. @chipmunkofdoom2 great 1st post writeup

 

[doughboy]

li-ion definitely costs more than SLA because it has a smaller footprint and lasts longer. each have its pros and cons.

on the diy setup, if unattended, it automatically switches to inverter output if power goes out. how does it prevent the battery from getting over discharged if left unattended?

 

[chipmunkofdoom2]

li-ion definitely costs more than SLA because it has a smaller footprint and lasts longer. each have its pros and cons.

on the diy setup, if unattended, it automatically switches to inverter output if power goes out. how does it prevent the battery from getting over discharged if left unattended?

In my opinion though, the benefits of Li-ion are not worth the cost for aquarium battery backups. The weight difference is likely of little to no benefit, as most people will not be moving the batteries around much after they install them. Charge cycles are likely not an issue either since this system will only discharge the batteries during an outage. If you only discharge the batteries twice or three times a year, in 10 years that's 20 - 30 charge cycles. It doesn't matter if lithiums can last for five thousand cycles if you only need 30 cycles in a 10 year period. Obviously if you're losing power many times a month, that's a different story, but you have other issues if your power is that unreliable. If you already have a big pack of lithium cells you want to use, by all means, go ahead. They'll work and they'll do the job just fine. If you're starting from scratch, though, I personally think a quality AGM battery works just fine for our purposes and is the most cost-effective option.

There is no discharge protection built into the system per se. Most inverters include circuitry that will not allow the battery to discharge too far. The three inverters I showed in the main article all claim to feature over-discharge protection. Even if you leave the system unattended and the inverter shuts off when the battery gets too low, you now have a whole different problem of water becoming stagnant and fish/corals dying. Over-discharge protection or not, you should have a plan of action for what happens when the batteries die.

 

[Porpoise Hork]

Since my main pump is 24v 2.9A DC (on max output) I devised a simple yet effective backup system for it. I setup a pair of 12v 35AH sealed solar power storage batteries and wired them in series. This gives me the 24v DC needed to drive the pump with a combined 70AH reserve. I have a 110v - 24V 10A LED driver power supply running through a diode circuit that is runs the pump as well as charge the batteries if needed. In the event of a power failure the main pump will continue to run for about 36 hours before I have to break out the generator for the pump. If at that point power is still out I have a 1KW 2 stroke generator that will easily recharge the batteries, drive the lights and heaters.

The reason I decided on this route was due to the large amount of loss through the voltage inverter that absolutely destroys the overall run time on battery backup systems.

Total cost : $285 with a 36hr continuous run time.
12V 35AH sealed solar batterys $65.00 per
Diode block \ Voltage regulator $20.00
1KV 2 stroke generator $ 95.00
24v 10A LED driver power supply $25
Various power cables, circuit breaker, and connectors: $15

Compared that to a large computer UPS unit that will run for 3 hours with similar load $278.00

 

[chipmunkofdoom2]

@Porpoise Hork that's certainly an option. Out of curiosity what voltage do you use to float your batteries? How do you manage sulfation? Do you ever use a charger to desulfate them?

You're certainly right about inverter inefficiency too. If you feel like going through the trouble of a DIY system and you have DC pumps, it might be worth exploring a DC-only system. This would bypass inefficiency in the inverter. It's worth noting though that some inverters have up to 90% rated efficiency. So inverters aren't always the power hogs that they are portrayed to be.

Also, just a nit-pick, when wiring batteries in series to double the voltage, the capacity stays the same. So you have 35Ah of capacity at 24VDC. If you were to wire the batteries in parallel, you would have 12VDC and 70Ah of capacity. With two batteries, you can double the capacity or the voltage, but not both.

 

[siggy]

If you feel like going through the trouble of a DIY system and you have DC pumps, it might be worth exploring a DC-only system.

I was thinking about this early on with using DC Pumps, Lights. So much energy is lost in transforming. Someday Electricians will run 24VDC ( or ?DC ) outlets in every room. MY samsung TV has an external supply,
LED lighting, computers & USB chargers to name a few then add Solar and Wind. So why take DC turn into AC then Back to DC........@chipmunkofdoom2 Great topic and can of Bait

 

[Porpoise Hork]

@Porpoise Hork that's certainly an option. Out of curiosity what voltage do you use to float your batteries? How do you manage sulfation? Do you ever use a charger to desulfate them?

You're certainly right about inverter inefficiency too. If you feel like going through the trouble of a DIY system and you have DC pumps, it might be worth exploring a DC-only system. This would bypass inefficiency in the inverter. It's worth noting though that some inverters have up to 90% rated efficiency. So inverters aren't always the power hogs that they are portrayed to be.

Also, just a nit-pick, when wiring batteries in series to double the voltage, the capacity stays the same. So you have 35Ah of capacity at 24VDC. If you were to wire the batteries in parallel, you would have 12VDC and 70Ah of capacity. With two batteries, you can double the capacity or the voltage, but not both.

Well I was wrong. I thought that both the voltage and AH increased when running in series. It will if you do a series/parallel with 4 batteries but not with just two.. So you're correct on the AH capacity. If I rewire it to go parallel I get the double AH capacity but voltage remains the same at 12v. To get the 24V 70AH then I would need a rather basic full bridge rectifier to up the voltage from 12v to 24v wile keeping the wattage draw the same. As for Sulfation as long as the batteries remain at full charge, or are not left in a state of low charge for an extended period of time then it wont be an issue. That's why I elected to go with a power supply unit that can provide up to 10A when the total draw on the system would be at best 24v 70w or 2.9A if the pump was at full power. And I oversized the pump and it is set to only run at 40% of max output so it only draws 1.8A. Eventually I do plan on replacing the lead acid cells with a Li-ion powerbank to hopefully provide a solid 7 days of reserve power to the entire setup, but that's for later down the road.

 

[kswan]

I had a recent outage that lit a fire under me to get a battery backup in place. This thread sealed the deal. I’m going in a little different direction for a couple reasons. The first is that I already have a battery backup for my sump pump that runs on a 12v deep cycle battery. This is a complete system that includes a battery tender.

My plan for the tank is to use the sump battery along with a second battery to create a 24v system for a UPS. I’m going the UPS route because I got it for free. The internal batteries are dead so I’m wiring in the extra capacity batteries in their place. If it doesn’t work I’ll build a transfer switch and ditch the UPS. I have an inverted on hand already.

If I understand correctly I can run a float charger on the second battery to keep that topped up as well. Is there any issue with this since it will be at 12-24v instead of 0-12v? My understanding is that the charger will not know the difference.

I built a shelf next to my mixing station to hold all of the equipment. I’ll also be mounting a DOS and some other Apex modules on the upper part. Finally I’ll use the Apex to detect an outage and turn off everything except the return pump at a low setting. My router will also be plugged into the UPS so I will receive notification of the outage.

Sorry for the long post. Let me know if anything sounds missing or incorrect.

 

[chipmunkofdoom2]

@kswan it's okay, I'm glad to help.

Personally, I would not attempt to add a battery to your sump pump. You can do it, but there are a few issues. The first is that in a 12VDC battery bank, ideally all the batteries should be about the same size. Because of the internal resistance in 12VDC batteries, different sized batteries will charge and discharge differently if you attempt to tie them together. This will wear out the batteries prematurely as one gets worked harder than the other. Even if you find a battery that's the same capacity as the one in the Ace, you still probably shouldn't tie them together. The internal resistance of batteries changes as they age, which means again, if you put together an old battery and a new battery, one works harder to pick up the slack for the other. So if your Simer is only a few months old and you can find the exact size of the battery inside of it, then you could potentially add another battery. I personally wouldn't though.

You mention wiring the batteries in series to get 24VDC. Do you know for sure that the APC takes 24VDC? Most use 12VDC. Assuming that the APC is like most UPSs and uses standard 12VDC, your system can be pretty straight forward. You'd really just need to disassemble the UPS, take out the internal batteries, and wire the external deep cycle to it. This might be easier said than done, since many APCs use proprietary batteries now. But, that's all you'd really need to do. The UPS would keep the battery charged automatically, so you wouldn't need the battery maintainer. The UPS would switch automatically to battery power on power failure and would switch back (and charge the battery) when the power comes back on. Provided everything else in the UPS still works, that is.

Personally that's what I would do. I'd keep the sump pump separate, wire the deep cycle to the UPS, and that would be that. This all of course depends on you hooking up the battery to the UPS, which might be easier said than done.

Also, the battery in the picture appears to be a standard flooded deep cycle. These batteries work for this application, but a few caveats apply. First, it appears the battery is not sealed. Be aware that during charging and discharging, this battery will produce hydrogen gas, which can be explosive if exposed to spark or flame. Second, if these batteries fail catastrophically, sulfuric acid will spill everywhere. Third, flooded deep cycles are more sensitive to discharging than absorbent glass mat deep cycles. I wouldn't aim to discharge this battery past 50% for optimal longevity. Lastly, flooded deep cycles are more susceptible to sulfation and electrolyte stratification. I would purchase a quality battery charger that has a dedicated desulfate cycle and charge manually every few months to combat these two issues.

While flooded lead acid batteries work for this type of application, they're not my favorite. Did you get that battery recently specifically for this purpose? If so I would consider returning it and getting an AGM battery. They are likely cheaper if ordered from Amazon and have a few additional safety benefits, as well as an 80% DOD.