DC to AC conversion for Kraken...

[afboundguy]

I am about to set up the Hydros Kraken and I am curious if anyone has converted DC power to AC? I have a 150ah battery for the backup and even powering two return pumps and two power heads I will get around 30 hours and figured I could add the skimmer into one or the 12V drive ports but skimmer pump is AC and Kraken power is DC.

I was curious if I could get a small inverter like this (https://a.co/d/ffObxN9) and cut the cigarette lighter side and wire in GX12 pins instead? I know I would lose some efficiency going from DC to AC compared to DC to DC but I have ample amps for the battery and I would love to keep the skimmer going as well and figured $20-$25 for the inverter and GX12 pin would be far cheaper than getting an AC UPS.

 

[tbrown]

Have you checked the CoralVue forums? There's a lot of DIY solutions over there.

 

[BryanM]

Inverters destroy DC performance. 30 hrs all DC stuff, if you add that skimmer with an inverter I bet it goes to somewhere around 5hrs... Its that bad, or it has been in my experience.

 

[afboundguy]

Have you checked the CoralVue forums? There's a lot of DIY solutions over there.

I have but I'm brand new over there so all my posts have to wait for moderator to approve them...

Inverters destroy DC performance. 30 hrs all DC stuff, if you add that skimmer with an inverter I bet it goes to somewhere around 5hrs... Its that bad, or it has been in my experience.

I know the DC to AC conversion loses a lot of efficiency but didn't think it was that much of a drop off and haven't heard of anyone having that much of a drop off.

I still might try and DIY and see as I have a battery meter and a small car inverter and ordered some GX12 plugs so we'll see!

 

[Malum Argenteum]

Inverters destroy DC performance. 30 hrs all DC stuff, if you add that skimmer with an inverter I bet it goes to somewhere around 5hrs... Its that bad, or it has been in my experience.

An inefficient inverter will waste more power than an efficient one. A cheap inverter might be 80% efficient, while a decent one can be 98%.

Another probably more important thing to consider is that the nominal wattage of the pump is its 'true power' draw, but since not all electrical devices are 100% efficient in using power the 'apparent power' usage will be higher -- and this apparent power is what the battery has to provide. The difference in these two numbers is the 'power factor'. There are some threads here regarding pumps with a seemingly very low power factor.

So, most of the discrepancy seen between expected battery life and measured battery life has to do with the fact that the battery has to supply the apparent power (while the power company only charges us for the 'true power'), and not with the inverter itself.

There are some actual electricians here who can likely check my claims here, but I have learned a lot about this sort of thing by running a small (~500w array) off grid solar setup for a bunch of years.

 

[afboundguy]

An inefficient inverter will waste more power than an efficient one. A cheap inverter might be 80% efficient, while a decent one can be 98%.

Another probably more important thing to consider is that the nominal wattage of the pump is its 'true power' draw, but since not all electrical devices are 100% efficient in using power the 'apparent power' usage will be higher -- and this apparent power is what the battery has to provide. The difference in these two numbers is the 'power factor'. There are some threads here regarding pumps with a seemingly very low power factor.

So, most of the discrepancy seen between expected battery life and measured battery life has to do with the fact that the battery has to supply the apparent power (while the power company only charges us for the 'true power'), and not with the inverter itself.

There are some actual electricians here who can likely check my claims here, but I have learned a lot about this sort of thing by running a small (~500w array) off grid solar setup for a bunch of years.

I still plan to test it out with the small inverter I have once I get the Kraken installed with the rest of the Hyrdos system and see how much time it takes off from the battery backup setup. In theory I don't need much more than 16 hours as that's the longest I'm ever stuck at work and I work in the town I live in so even when we lose power I typically can come home and setup the generator.

 

[n2585722]

Have you thought about getting a UPS and powering a wifi strip with it and then plug the skimmer into it. I use one to power my router and cable modem. I think of a no power event as an emergency and the only pumps I have running is wave pumps and those drop to a low flow rate to help save battery power. None of the other pumps or the heaters run when there is no power.

 

[afboundguy]

Have you thought about getting a UPS and powering a wifi strip with it and then plug the skimmer into it. I use one to power my router and cable modem. I think of a no power event as an emergency and the only pumps I have running is wave pumps and those drop to a low flow rate to help save battery power. None of the other pumps or the heaters run when there is no power.

I actually have thought of this and ordered a used UPS on eBay with and a new battery. I have a small Amazon powerstrip/UPS that I was using for my phyto air pumps and plan to move that to my router and replace it with this new UPS and run the air pumps and skimmer.

I am switching over to Hydros and have 3 wifi power stripes and hadn't thought about doing it that way but that would work! Worst case scenario I could always buy a larger battery for the UPS as well...

 

[afboundguy]

Have you thought about getting a UPS and powering a wifi strip with it and then plug the skimmer into it. I use one to power my router and cable modem. I think of a no power event as an emergency and the only pumps I have running is wave pumps and those drop to a low flow rate to help save battery power. None of the other pumps or the heaters run when there is no power.

If I keep power to the wifi power strip and when the Kraken senses loss of power and kicks into low power mode since the wifi power strip would still be powered I should be able to turn off certain outlets on the strip correct?

 

[n2585722]

If I keep power to the wifi power strip and when the Kraken senses loss of power and kicks into low power mode since the wifi power strip would still be powered I should be able to turn off certain outlets on the strip correct?

yes you can set which outputs are still active in each mode so just uncheck the ones you do not want to be on in active in modes for the low power mode. Your router for wifi will need to be on the UPS also though since it is needed to communicate with the wifi strips. I also have my cable modem on the UPS as well. So normally I do not loose internet when there is no power so my phones and iPads will still work during a power outage.

 

[afboundguy]

yes you can set which outputs are still active in each mode so just uncheck the ones you do not want to be on in active in modes for the low power mode. Your router for wifi will need to be on the UPS also though since it is needed to communicate with the wifi strips. I also have my cable modem on the UPS as well. So normally I do not loose internet when there is no power so my phones and iPads will still work during a power outage.

Thanks! I have a UPS coming for the router so I can still get notified if power is lost.

 

[Marc G-L]

Just make sure you place the inverter in a vented location. Depending on the power draw, over time the inverter fan will kick on and blow some heat. Many have an aluminum housing as a heat sink and will shut down if too hot, causing power to drop to zero.