Is running my water maker going to kill my batteries

[Ded reckoner]

Our experience is similar to chrisr's:

we have a 4000w inverter and 650 ah batteries (with 675w solar + 400w wind) and there is no way we can run the w/m from the batteries without running an engine or 2.

We have a Spectra Catalina Compact 13gph watermaker. The issue is the V drop for the system and the watermaker V requirement. We have 880W solar and a D400 wind generator. If we start with batteries fully charged and the sun is nearly overhead on a clear day, we have a couple/few hours we can run without having to either turn on the generator or engine. If we make water at night, we have to run one of those to keep the battery V high enough we don't get a fault.

[noelex 77]

Originally Posted by Ded reckoner

Our experience is similar to chrisr's:
We have a Spectra Catalina Compact 13gph watermaker. The issue is the V drop for the system and the watermaker V requirement. We have 880W solar and a D400 wind generator. If we start with batteries fully charged and the sun is nearly overhead on a clear day, we have a couple/few hours we can run without having to either turn on the generator or engine. If we make water at night, we have to run one of those to keep the battery V high enough we don't get a fault.

The Spectra Catalina only consumes 18A @ 12v. From a typical battery bank installed in a 43 foot sail boat you should be able to run this unit without so much voltage drop that the watermaker shuts down unless the batteries are in a very low SOC. This is without the input from your 880W solar and/or D400 wind generator.

Either your batteries are in poor condition, the wiring is inadequate or something else is wrong.

[wathey]

Repeating what Noelex77 asked. 14a @ 110v AC or DC? It doesn't make much water if it's 14a DC. If its AC that is inline with many water maker pumps. Your 70a generator is rated in DC, unless it's a balmar it's 12v70a . With those assumptions for which I could be incorrect, the draw is 141.6 amps. If its 14a at 12v you should have no problem with the draw.
If its 14a at 110 then your battery bank is lead acid and rated for 50% discharge giving 220ah usable so you can run your watermaker for an hour and half. I think the little Honda though could likely power it but you would need to do the watt conversion to see.
I'm running our watemaker right now. 1700watts pump draw (60gph) - 1400ish watts from solar (1130am in Bahamas) so 300watt draw or about 25ah from battery bank.

[boatpoker]

Originally Posted by noelex 77

Is that 14A @12v or 120v ?

+1
The single most important (unaswered) question !
Is the water maker 120V running through an inverter,
If that is the case, yes it will rapidly drain your batteries.

[Ded reckoner]

Originally Posted by noelex 77

The Spectra Catalina only consumes 18A @ 12v. From a typical battery bank installed in a 43 foot sail boat you should be able to run this unit without so much voltage drop that the watermaker shuts down unless the batteries are in a very low SOC. This is without the input from your 880W solar and/or D400 wind generator.

Either your batteries are in poor condition, the wiring is inadequate or something else is wrong.

I don't have the numbers, but I think the autopilot is consuming a relatively large amount of current, too; I think all the other instruments add up to less but are significant. My understanding is the V drop from the batteries to the watermaker varies with water temperature and battery float V (and, I think it will vary with salinity, too). We're seeing nominal V drop of about 0.4V-0.5V. I think we get a fault when the V at the watermaker is at 11.80V. This means, with all the systems running, our new 500Ah house bank starts with a float V of 13.3V and it needs to stay at or above 12.2 or 12.3V to avoiding the watermaker faulting. The watermaker makes about 13gph and we have to run it about 8hrs to fill one tank. 18Ax8hrs=144Ah. Plus there's the load from instruments, autopilot, and anything else. I think the summary of all this is operational hours need to be limited, or else battery charging by some means is needed to avoid battery drawdown.

[moseriw]

Sorry folkss but buying a consuming unit requires building up knowledge how to feed these things. This is nothing to ask here but hard work to find out yourself.

Same like the guys who want to run a 60 Kw E-engine with a 75Ah 12V battery na 2 100 Watt solar panels.


It simply sucks.

[ShoreFun]

I think the answer is the poster should take some time to read about energy management. Please keep in mind I am not purposefully trying to be mean to anyone, I am not always the best at wording.

Will it hurt the batteries? That answer comes from learning about how batteries get hurt which he needs to know so he does not hurt is batteries. A simple light left to bring the batteries, lead acid, below the 50% point and he had hurt his batteries.

Then there is the question of how are the batteries being charged? If they are not charged properly they can be damaged too.

The OP needs to have a reasonable understand of these issues unless he does not mind buying batteries often.

Once those points are understood then he can answer his own questions. He needs to know how to monitor the battery bank so he does not hurt his batteries.

As an electronics engineer I am often answering electrical questions. Most people are scared of the thought of electrical things. The battery stuff can be understood on a basic level and does not need much math so you should not be scared of it.

What he really needs to be scared of are his connections. Does he know how to inspect and check they are all clean and tight. Nothing ruins your day then a bad high current connection.