nemo pump

ihuntbear

anybody use or heard about a nemo 24 volt submergible pump.I'm looking for an off grid pump for a remote cabin in the woods.I have two 30 watt panels and a charge controller charging fork lift batteries 12 volt system for lights.I was thinking about having another fork lift battery to make 24 volt for p the pump.The well is 100 feet deep,60 feet of casing.water is 32 feet down.I use a 110 volt submergible pump with a gernerator right now for water but hate the noise of the gen.So I need a pump to work off the panels and batteries.Seen this nemo pump on ebay but never heard of it before.Also what do you guys do when its below freezing ,do your pumps pump down when your tanks are full?

arkieoscar

Re: nemo pump

I'm always looking for good ways to pump water and did a quick search on the nemo pump. It appears to be a conventional DC motor driving a positive displacement pump. If it's well made, it should do what you want although I'm sure you will hear about the fact that you don't have enough solar to keep your present battery charged much less charge another set.

BB.

Re: nemo pump

This is the Nemo Pump?

-Bill

BB.

Re: nemo pump

ihuntbear,

If you can, please keep your related questions/posts in one thread... Less confusing for everyone who replies.

-Bill

ihuntbear

Re: nemo pump

how much solar would i need to work this pump ? I know to answer that question you need to know how many time it will cycle on and off . Well I'm there only on weekends and hunting season.Without the well pump I have to to charge the batteries once a week,sometimes i need to start the generator even though I have the panels working but those cloudy days are a pain.I hate that noisy gen

ihuntbear

Re: nemo pump

BB I didn't know it went out to more than one tread sorry

BB.

Re: nemo pump

ihuntbear,

Not a problem--It is easy to put things back into their proper place.

I will delete the extra post now...

-Bill

ihuntbear

Re: nemo pump

if i'm using 24 volt pump and have two 30watt 12 volt panels ,two sets of 12 volt fork lift batteries,I know i can hook the batteries and panels in series to get the 24 volts but how do I charge the batteries from the 12 volt windmill on those windy nights and cloudy days

BB.

Re: nemo pump

The, at least from me, go something like this:

1. Have you done all of the conservation you can (cheaper to conserve than to generate power).
2. What is the peak watts (or Amps*Volts), average power, and daily power usage (Watts*Hours per day).
3. If you already have an existing system, what is the Amp*Hour rating of your bank, the operating voltage, type of batteries (flooded cell, AGM, etc.).
4. And if you have an existing system, what is the wattage/Vmp/Imp of your current panels
5. Where is the system (roughly) located.
6. What are your expectations (what seasons, backup genset, etc.).

The heart of your system is your battery bank. If treated well, it can last the better part of a decade. If not, it might not last more than 1-3 years (of course, quality and battery type/size has a play in the equation too).

Generally, we try not to cycle the batteries below 50% state of charge very often (long life), and never below 20% state of charge as you run the risk of permanent damage. Also, we try to get a battery recharged quickly (within a day or so) above ~75% state of charge--If the battery stays below 75% for days/weeks/months at a time, the batteries will sulfate and die from lack of capacity.

So--Even though you may spend two out of seven days in the cabin, you should not fully discharge the battery and then plan on it recharging over the next 5 days--That will age the battery fairly quickly.

Another issue with forklift batteries, is as they age, they can have a fairly high self discharge rate (1-2% per day or more) near the end of their life... So, even a small 5% * 20 Hour battery rating will just keep up with self discharge when the batteries are old.

Regarding the 12 volt vs 24 volt for a wind turbine--You are correct that, for the most part, wind turbines will produce more power on a 12 volt bank vs a higher voltage bank (of course, there are sometimes higher voltage options, or you could use a 12 to 24 volt doubler to charge a 24 volt bank from a 12 volt wind turbine/small battery system).

If your power usage is less than ~1,200 watts continuous loads--you can probably stick with the 12 volt bank. Although, with the 24 volt pump and possibly other loads--it is a tough call between the 12 or 24 volt bank.

I am not a big believer in wind power as a general solution--so I would tend to choose the 24 volt bank unless the power needs were quite low (and I had other 12 volt requirements). Otherwise, a nice 24 vdc to 120 vac sine wave inverter to power the balance of the random loads (cell / battery charger, small computer, radio, lights, etc.).

-Bill

ihuntbear

Re: nemo pump

.I found a 12 volt to 120 volt 3000 watt 5000 peak cobra inverter .would this get my 120 volt submerge pump working.The camp lights are all 12 volt and propane. The only problem I have is the water pump ,its 120 volt ac.

BB.

Re: nemo pump

A 3kW 12 volt inverter is difficult to implement from a Battery/Wiring side of the issue... For example, a 3kW continuous power would require:

• 3,000 watts * 1/10.5 min volt * 1/0.80 eff * 1.25 NEC safety factor = 446 Amp

So, the wiring/fusing/breaker/switch would need to be designed with a minimum of ~450 amp rating.

If you need 3-5kW of power (including surge current)--You really should be looking at a 48 volt battery bank (then you would be looking at around:

• 3,000 watts * 1/42 min volt * 1/0.80 eff * 1.25 NEC safety factor = 112 Amp

If you need around 1,200 watt maximum, you should look at a smaller inverter that better matches your loads and you could stay with 12 volt system.

-Bill

ihuntbear

Re: nemo pump

so would i be better off getting rid of the 120 volt pump and spend my money on a 24 volt submergible pump and add more panels to what I already have to power it and the camp up

BB.

Re: nemo pump

It depends...

How big is the pump now (110 VAC at what current/horsepower) and what kind of starting setup it has (2 wire, 3 wire with capacitor above ground, etc.). Also, how far is it from the battery bank to the well.

It is very difficult to send low voltage very far. So, a small, efficient, AC pump with appropriate inverter may still be the right choice.

Do you have an above ground cistern/holding tank/pressure tank to store the water?

Many times, for internment/seasonal use--Having above ground storage and a gasoline generator powered well pump with a small DC pump from tank to cabin for pressurization is a good compromise.

Solar and related hardware can be a nice choice if operated > 9 months of the year... For sporadic weekend and couple weeks during the year--The expensive solar panels, batteries, high efficiency well pumps, and inverters sit unused most of the time. And if one of the heavy use seasons is winter (or during poor solar conditions of clouds/shading)--then pure solar is a very difficult trick to pull off.

If your pump is on the small size and can be powered by a, for example, a Honda eu2000i (or possibly a Honda eu3000i or one of the Yamaha or other equivalents)--you get rid of much of the noise issues. And, many times, using a smaller genset better matched to your loads is more fuel efficient.

You can also start with a smaller solar array... "Just enough" for keeping the bank charged and some light weekend use... And for heavier use, toss a decent AC battery charger on the genset to bump up the batteries every day or too.

Later, as justified by your loads, you could add more solar panels and reduce genset use.

Without knowing more about your DC/AC daily loads and cabling lengths/power needs--It is difficult to be more specific.

In the end, the battery bank is very susceptible to over/under/deficit charging... Plan your power generation and energy usage around keeping your battery bank "happy" for a long and trouble free life for your battery bank.

-Bill

ihuntbear

Re: nemo pump

i talked to the pump installer ,he said the pump is 110 volt 1/2 hp roughly 990watts, pump is two wire.I don't know if he knows what he is talking about when it comes to watts because my generator loses rpm when pump starts up.The gen is brand new. I looked at the gen and it says its 2800 / 4000 watt.The installer said the head for water is 32 feet,pump is 75 feet down.batteries to well is 10 feet.I just ordered 2 more 120watt panels off ebay.Do you think I need more panels or am I good.I run 3 - 13 watt dc flourecent lights for about 6 hours a day when I'm there and would like to have fresh drinking water from the well.I could buy the 24 dc volt nemo pump and use a small inverter or use the 110 ac pump with a big inverter.again i hate the generator

BB.

Re: nemo pump

The Nemo pump may meet your needs nicely... From their website (my earlier post) they give information on sizing your electrical for the pump. Looks very nice for a 24 volt system. The pumps are diaphram type and a brushed motor. It looks like you will get around 2,000 hours of service from the pump (assuming you get all the electrical wiring properly sealed and don't overload the pump or restrict water flow). Assuming it is relatively easy to access the pump in the well, it looks to be a nice compromise.

Regarding how much power / solar panels you will need... Without knowing your loads and seasonal usage--It is hard for me to guess.

Approaching the problem from the other way, using PV Watts website, and Caribou Maine's solar data as being close to your location... Use 1,000 watts (1kW) of solar panels (even number), 0.52 system derating (solar panels to AC inverter output--yes, about 1/2 your power is lost through marketing numbers to AC outlet), fixed array tilted at latitude:

"Station Identification"
"City:","Caribou"
"State:","Maine"
"Lat (deg N):", 46.87
"Long (deg W):", 68.02
"Elev (m): ", 190
"PV System Specifications"
"DC Rating:"," 1.0 kW"
"DC to AC Derate Factor:"," 0.520"
"AC Rating:"," 0.5 kW"
"Array Type: Fixed Tilt"
"Array Tilt:"," 46.9"
"Array Azimuth:","180.0"

"Energy Specifications"
"Cost of Electricity:","12.2 cents/kWh"

"Results"
"Month", "Solar Radiation (kWh/m^2/day)", "AC Energy (kWh)", "Energy Value ($)"
1, 3.36, 58, 7.08
2, 4.34, 67, 8.17
3, 5.23, 86, 10.49
4, 5.75, 89, 10.86
5, 4.99, 74, 9.03
6, 5.09, 71, 8.66
7, 5.15, 73, 8.91
8, 4.99, 72, 8.78
9, 4.26, 61, 7.44
10, 3.45, 53, 6.47
11, 2.38, 35, 4.27
12, 2.73, 46, 5.61
"Year", 4.31, 784, 95.65

So, for 1,000 watts of panels, you will get around 35-89 kWHrs per month... For worst case November on solar, you will average (remember this is 20 year average weather--a week of heavy cloud cover will give you 1/10th or less solar power--No sun, no power):

• 35 kWH / 30 days = 1.2 kWH per day = 1,200 WH per day per 1,000 watts of solar panels

If you have 300 watts of solar panels:

• 1,200 WH * 300 W / 1,000 W = 360 WH per day

Say your pump pulls 3 amps @ 24 volts for 1.5 GPM flow:

• 360 WH / (3 amps * 24 volts) = 5 hours of pumping

Realistically, you probably would use the pump for 1 hour per day (60min*1.5gpm=90gpd of water).

• 360 WH - (24v*3a*1h) = 288 watts
• 288 WH / 6 hours of use per night = 48 watt average AC load for lights/radio/computer/etc.

One thing you have not told us about is the actual size (amp*hours) of your 24 volt fork lift battery bank. Fork Lift batteries can have fairly high self discharge (on the order of 1% per day) when they get "old"... If you have small panels and a large battery bank, your solar array may not be able to keep up with the self discharge of your bank + loads.

Also, the above calculation for your DC use does assume the loss of an 85% efficient inverter--So, there is a 15% hit which overestimates the load on your system... Trying to keep the concepts simple... If you have a lot of DC loads, we can break them out separately or you can multiply them by 0.85 do account for the non-use of an AC inverter to power them (not a huge difference either way).

And the above is based on November usage--Obviously you will get 2x the amount of power for 6 months of the year.

-Bill

ihuntbear

Re: nemo pump

can I charge the battery right from the gen if I don't have enough sun or do I also have to use a battery charger

BB.

Re: nemo pump

It depends on what kind of generator you have... There are DC output gensets, and AC output gensets, and those that have both AC and DC output.

The Honda euX000i series has both a 120 VAC output and an 8 amp 12 VDC output for battery charging...

The 8 amp 12 volt output is unregulated and not very large. Plus you have to run with ECO Throttle off (engine at high speed) (plus one person's eu2000i has a label that says not to use the DC output and AC output at the same time).

Basically, for an eu1000i, you can easily power a 20 amp 12 volt / 120 VAC battery charger to quickly recharge the bank (20 amps vs 8 amps peak) plus the genset can run in ECO Throttle on mode and use less fuel.

In general, I like to size the the genset to the loads... A small battery bank needs a smallish battery charger and genset for best fuel economy. You don't want a 5kW genset running a 20 amp (~600 watt or so) battery charger.

Sometimes, you will end up with two gensets... A small / fuel efficient genset to recharge your battery bank and a larger one to power your shop tools/well pump when needed (and can be your emergency backup).

-Bill

ihuntbear

Re: nemo pump

I ran out of power this weekend ( no sun ) hooked up the gen DC side red to pos and blk to neg.It kept blowing the breaker on the DC side so I disconnected it .My battery charger is 30 minutes away

BB.

Re: nemo pump

What brand/model of generator and what breaker (size) was blowing?

Probably, the little DC output for the Honda type gensets is designed to charge a car battery--much smaller than the typical RE battery bank (50-80 AH vs 100's or more of AH for your cabin bank). That may cause problems with their small/unregulated charger.

-Bill

ihuntbear

Re: nemo pump

its a Champion 2800 4000 max watts.I don't know what size breaker .Its the small push reset one.It kept popping so I turned the gen off.Bought it at cosco

ihuntbear

Re: nemo pump

sorry its also a 8.9 amp dc

BB.

Re: nemo pump

If you had an extension cord or something to add some resistance to limit peak current until the batteries are somewhat recharged--It may work better...

But, otherwise, to properly (and quickly) recharge your battery bank, you need a "real battery charger" with 40+ amp @ 12 volts or 20+ amp @ 24 volt (I am not clear on your battery bank size/configuration).

8 amps is just not a heck of a lot of power into a large battery bank.

You want, roughly 5% to 13% (or even as high as 30% would work) times the battery bank's AH rating (i.e., a 500 AH battery bank * 10% would be a 50 amp charger).

And, you have to match the charger to your genset's output rating (battery chargers are usually very "hard" on a genset because of poor AC Power Factor--So the genset typically needs to be larger than you would expect based on watt ratings--Look at the VA (volt*amp) rating of the power supply vs Watts/VA rating of genset).

• 500 AH / 8 amps = 62.5+ hours to recharge
• 500 AH / 50 amps = 10+ hours to recharge

A huge difference in fuel and generator run-time.

-Bill

ihuntbear

Re: nemo pump

thanks Bill.You are full of Knowledge