12 volt Emergency portable bilge pump

[T. Lee]

Looking for a comparison chart of high flow, 12v, 6-7ft head, bilge pumps. Wiring would be terminated with alligator style clips. I’ve used small versions to pump out small boats and would like to bump up the capabilities. I would use enough wiring to reach any on my 12v batteries (catamaran)
Odds are it would never be used but one never knows.
Thanks

[rslifkin]

Something like a Rule 3700 or 4000 is probably as good as you'll get for 12v. Flow at 2m / 6.6 ft head is rated to be 2450 and 2950 gph, respectively.

[Paul L]

Not a direct answer to your question, but an alternative. You can purchase AC basement sump pump. These are robust, low cost and high true volume. When you need a crash pump you'd use the inverter or genset to do the high volume pumping.

[sailormed]

What I understand from your target use I would go for an AC pump. The voltage loss in long DC cables is quick getter to important to have a good performance from a 12V pump. An AC pump and an ~500W converter looks me a better solution as you can increase cable length without voltage drop penalty.

[T. Lee]

Thank you for your replies. I am only considering 12 vdc for it’s commonality. I appreciate the thoughts about AC powered pumps and have used plenty of them in controlled situations, but for me, I’ll trade less flow for safety and portability.

[rslifkin]

I just remembered: Rule sells what they call the Evacuator 8000. It's a pair of 4000 GPM pumps tied together with a common 3 inch output. It's got a carry handle and 12v clamp leads, as it's meant to be portable. Rated output at 2m / 6.6ft head is about 5900 gph.

[Lake-Effect]

Originally Posted by T. Lee

Looking for a comparison chart of high flow, 12v, 6-7ft head, bilge pumps. Wiring would be terminated with alligator style clips. I’ve used small versions to pump out small boats and would like to bump up the capabilities. I would use enough wiring to reach any on my 12v batteries (catamaran)
Odds are it would never be used but one never knows.
Thanks

I put a 4000 gph 12v submersible bilge pump into our house's sump pit as part of a secondary system (we got flooded once when the power was off). It has about a 1-1/2" outlet and pumps like a fiend at under 20A. More than enough head. That's about the largest pump that I think I'd want to carry around and run off of battery clips.

But I don't understand why you're contemplating a portable for your cat. If you're worried, and assuming that each hull has a common bilge area, I would permanently install 2 (or 4) really good pumps. They're not that expensive.

[tkeithlu]

Pumps are an issue, but powering them is another. Batteries are mounted low, so very quickly they will be under seawater, with spectacular results. The biggest pump available then is useless.

Consider two possibilites. The first is to drive your Oh My Gawd pump with the engine rather than a battery. The second is to cross wire, so that your starboard pump is run off a port battery and vice versa.

[Lake-Effect]

Originally Posted by tkeithlu

Consider two possibilites. The first is to drive your Oh My Gawd pump with the engine rather than a battery. The second is to cross wire, so that your starboard pump is run off a port battery and vice versa.

It would be easier to install such a cross-wired pump system now, than to have to deploy it in an emergency.

[anacapaisland42]

Is this intended to be a manual or automatic pump, if automatic look for best switch, that;s the art that is the weakest
Bill

Originally Posted by T. Lee

Thank you for your replies. I am only considering 12 vdc for it’s commonality. I appreciate the thoughts about AC powered pumps and have used plenty of them in controlled situations, but for me, I’ll trade less flow for safety and portability.

[RaymondR]

Originally Posted by Paul L

Not a direct answer to your question, but an alternative. You can purchase AC basement sump pump. These are robust, low cost and high true volume. When you need a crash pump you'd use the inverter or genset to do the high volume pumping.

Carried one in my old boat for years. It had an included float switch and I used to plug it into the mains voltage in the marina at any time I left the boat for an extended period.

[T. Lee]

My boat does have 4 bilge pumps per hull @24vdc and I think that’s fine. Tossing a 12 v into my dingy to pump out another boat gives additional usages. Hopefully few and far between. Thanks T. Lee

[doog]

Originally Posted by tkeithlu

Pumps are an issue, but powering them is another. Batteries are mounted low, so very quickly they will be under seawater, with spectacular results. The biggest pump available then is useless.

Consider two possibilites. The first is to drive your Oh My Gawd pump with the engine rather than a battery. The second is to cross wire, so that your starboard pump is run off a port battery and vice versa.

DC batteries are not useless when flooded but maintain their charge for quite some time. Boats have sunk with the lights all blazing for a long while and Ive flooded my battery compartment accidentally with double trojan 104s and only found it days later, pumping it out with little damage..DC operates fairly well underwater with low voltage..

There are no spectacular results from this.

[lhuff35204]

This is the one I built. Portable so you can pass it over to another boat in need. Also remember that you can close the engine cooling thru hole, remove the hose from the seacock and use it as an engine driven suction.

https://www.amazon.com/Listed-YCIND-...Y0H0QQ7ZE&th=1

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

https://www.amazon.com/Seaflo-Heavy-...s&sr=1-2-fkmr0

[rslifkin]

As far as the batteries getting flooded thing, it's also boat dependent.

On my boat, by the time you've gotten water to the tops of the engine batteries, the engines are already partially submerged. Not enough that they wouldn't stay running, but enough that you're in trouble soon and you probably can't start them as the starters are getting wet.

Top of the house batteries are a few inches higher than that. By the time those are wet, there's enough water in the boat that you're in very serious trouble. The idea is that pumps and alarms should start to manage the solution and alert you to deploy any extra pumps you have and start damage control before the electrical systems get knocked out.