Electric Bilge System

This page is to track my progress in designing and building an electric bilge system that can be integrated into whitewater canoes.

Last update 7/28/05

The Electric Bilge Pump in Action on a Bell Prodigy X

Current Setup

Pump: Attwood - V-Series Bilge Pump 1250GPH. Submersible 12V pump draws only 3.3 amps, and will pump 20 gallons of water per minute.

Battery: NiMH 10cell 12V 4500 mah pack. I was really tempted by the LiPO batteries to drop weight, but they don't work well in cold environments and let's face it, unless you are in Costa Rica, whitewater is a cold environment. The NiMH pack weighs 2 lbs, and will power the pump for over an hour. The battery fits inside an Otterbox, which I can mount inside the pedestal. I bought a charger from the same place I bought the batteries. www.batteryspace.com

Switch: Cole Hersee - Waterproof On/Off Toggle W/Boot. It belongs inside submarines, it is expensive, but a switch that isn't totally waterproof won't do much good. *Note: The switch arrived 11/22  It is very well built, the unit looks like it was dipped in black plastic, covering everything except the metal toggle. There is an O-ring inside the toggle to keep it waterproof. The rubber toggle boot will keep silt, mud and splash off the switch. There are no markings on the switch, and I won't know which position is on or off until I run test current through it. I want it to be up for on, down for off, and I will install it in that position. *Note: I've been told this link to Amazon.com may give a No Items Found response. West Marine also carries the switch, though they are more expensive than the Amazon.com link.

Waterproof Case: I have both 8000 OTTER BOX  and 9000 on order. The battery pack will fit in both, but the 9000 might be better depending on where I end up mounting the battery.

Thru-hull fitting: I've opted for a 90 degree plated thru-hull. They are chrome plated plastic, which look similar to Stainless Steel, but without the weight. The 90 degree is to prevent kinks in the hose. As it sits, the hose runs along the bottom of the boat, then runs up the inside stern. To attach a straight fitting requires kinking the hose. The 90 degree lets the hose remain relatively straight.

Solar:  Some people have asked me about solar recharge ability. Instead of an integrated solar setup, I decided to have a separate solar panel/ battery system. The solar would recharge a second battery, instead of only having one battery. Not only does this give me two 12V batteries I can use as a general power supply (recharge camera, laptop, whatever), but it also gives me a redundancy by having a spare battery. The solar setup at some point will consist of a flexible solar panel with the wires leading into a waterproof box (probably an otterbox) that holds the spare battery and any necessary adapters. In the afternoons, this lightweight system can be brought into camp, set on a ledge, or placed anywhere it will get good sun. I don't have to worry about keeping the boat in the sun, because I can move the solar panel/ battery to the best sun. With the system as it is, the solar arrangement would be unnecessary for trips of a week or less. I should get almost 3 hours run time on two batteries (main and spare), pumping almost 4,000 gallons of water. That should be more than enough on and off cycles for shorter or less technical trips.

Update on Solar: The cost for a solar recharging system with extra battery is running $150. This includes a 5 watt flexible waterproof solar panel producing 16.5V at .3 amps. The panel is 22" x 10", and weighs 1.2 lbs. Cost is $77.50 (plus shipping). An 11 watt panel is available at 16.5V and .62 amps, with a size of 22" x 17", weight of 2 lbs and cost of $149.50. If the goal is just to keep the pump charged, the 5 watt system is adequate. If the goal is to use the system as a power supply for electronics, then the 11 watt would be the way to go.

The solar panels plug into a charge control which regulates the current and keeps the panels from frying the batteries. A 4.5 amp 12V charge control costs $25.50. Add to that the cost of another Otter box or similar case, and an extra battery and the solar recharge with spare battery will run about $150.

The Thru-hull fitting as seen from the outside, and inside with the hose attatched

The rear of the saddle, the battery box mounted in the saddle, and the outlet hose.
The Attwood 1250 is mounted inside the pedestal

Another view of the battery box installed in the saddle, with the outlet hose directly below

The simple wiring inside the Otterbox. The 5amp fuse can be seen on the right.
I put different colored tape on each battery to identify them, so I know which is charged/ drained.

Pump intake on the sides of the saddle. When sitting on the pedestal, this is the lowest part of the canoe.

The Pump as seen from the intakes. The on/off switch is shown below

This page has been added to several times without much editing. Below I have written my thoughts and logic as I was designing and building this system.

I have had several people ask me to sell them this system as a retrofit kit. As you can see, you'd need a Bob Foote pedestal to mount the pump on the inside, and if the pedestal is already mounted, you're going to have to rip it out. I haven't figured out how to mount it to Mike Yee pedestals, it won't fit inside them, so some type of external mounting would be required. You'll have to figure that out yourself, since I really like the clean aspect of having everything inside the saddle.

We've been using these boats for most of the season without problem. The pump will vibrate when it's battery is getting low. We've been leaving a battery in for about a month, and that seems to be how long one charge will last. For more technical water, or longer trips we'd have to change the battery more frequently, but it is lasting much longer than originally planned.

The pump drains the Prodigy X in about 15 seconds, the Nexus takes about 25, but the size of floatbags and their level of "full" influences that time. Loose floatbags let the boat hold more than twice the water of tight ones, and the drain time with somewhat loose bags is over 30 seconds for the Prodigy, 45 for the Nexus.

Installation

Cosmetically the pump would look best behind the seat. However until I fill a boat with water and test it, I don't know if I want it in front of or behind the seat. I will put the pump wherever it drains the most water. I suspect this will be between my knees, at the front of the pedestal.

If the pump is behind the seat, I will run the hose out to the stern so the water shoots out the rear. The battery case will be cut into and mounted inside the pedestal, and the switch will be mounted into the front of the pedestal. This will be a very clean installation, with all the wires hidden inside the pedestal, and the water stream staying out of the way.

If the pump is in front of the seat, the thru-hull will be on the left side of the boat in front of my knees. Though it would be tempting to put the hose to the bow, making an awesome water fight machine, that requires too much hose for good pumping, and the pressure from waves will further reduce pumping. The battery may still be mounted inside the rear of the saddle, since I might not have room up front. The outlet will be on my left, allowing me to paddle on the right without being in the outlet stream.

The pumps will be going into a Bell Nexus and a Bell Prodigy X, both fully outfitted with Mike Yee Pedestals, double strap systems, NRS bags, etc.

Progress

11/22     The Cole-Hersee switches arrived today. They are perfect for the job. The switch housing is covered in plastic or vinyl all the way down the wires. The switch has a visible gasket on the inside, so it is waterproof even without the rubber toggle boot. I'll still use the boot to keep silt out of the switch. I would like to find some replacement boots in case this one tears.

Dave asked me about the batteries I am using. I ordered my 12V pack and charger from Batteryspace.com . Their prices change daily. The coupon code "batteryspace" will get you 5% off the order. The 12V system I am using for this first series will fit perfectly inside an Otterbox 8000. Batteryspace also has a 13.2V cell for bike water bottles. I considered it, and might use that on future systems, but I wanted to keep everything within the pump specifications until I can test it firsthand.

UPS says my pump and batteries will be here Wednesday. Sometime after Thanksgiving I'll fill a boat with water and measure both the speed at which the pump removes water, and the true battery life of a fully charged pack.

11/23   Ordered the Otterboxes, solar panel and charge control. Now all I need to find are the thru-hull fittings. The specs on the solar panel, per the manufacturer, are putting the charge time a little higher than 10 hours for a seriously drained battery. The pump shuts off if current drops below 9V. Only testing will determine true battery life and recharge time, which is why I went ahead and ordered the solar panel.

11/24     The batteries/ chargers and bilge pumps arrived today. The batteries are the heaviest part of the system, weighing more than the pump and switch combined. I look forward to charging them and seeing how long the pump will operate on a charge.

11/27

This is the current layout for the pump system. The battery and 5 Amp fuse will sit inside an Otterbox which is mounted inside the pedestal.

The wires coming from the battery and switch will go into a 2oz Nalgene bottle. The wires from the pump will go through the lid of the 2oz Nalgene bottle. The wires will connect inside the bottle, where they will be waterproofed. This will allow for the removal and easy replacement of the pump.

The pump mounting bracket will be drilled into the nylon crossbars which hold the footbraces onto the pedestal. That should help prevent it from shifting.

I went into Radio Shack today for solder and various parts. That was a waste, they are not the store they were 10 years ago. I found half of what I needed there, and another half at Lowes. 16 gage wire, shrink connectors, inline fuse holder, more RC connectors, voltage meter, etc.

The cost of the system will exceed $150 if the necessary tools to create, test and install are added to the price.

12/04     I found a series of waterproof electrical plugs online. I'm going to use them instead of the nalgene bottle system, because it will look better and won't twist the wires. Otherwise all parts are in, except for those connectors. I have been too busy to begin building the full system, I've just been playing around with various parts. I will update as soon as I start actually building the system.

12/05  The waterproof electrical plugs are made by Bulgin Components of England. They are sealed plugs, waterproof to 10m. I have ordered 2-pin versions of the plug and a base plate mounted socket, long with caps for both the plug and socket, and the gold plated connectors. They are currently on backorder, so no knowing how long that will take.

Click Here for the datasheet on these connectors.

12/16  Still waiting on the waterproof connectors. I've been playing around with mounting the battery and pump, and decided that the battery and switch can both be inside the Otterbox, with the waterproof connector leading to the pump. The Otterbox mounts best to the front of the pedestal, and I'm going to mount it with some poly straps and buckles. That way it's quick release for portage/ transport/ storage. The pump disconnects from the base, so the only things actually mounted into the boat are the pump base, hose, thru-hull, and the buckles that the battery/ switch will connect to.

1/11/05     Sorry about the delay. I've had to put the pump on the back burner, but now that my new playboats came in, I'm ready to get it done. The design has changed again. The Bob Foote saddle has enough room to let me mount the pump inside the saddle. The battery can also mount inside, and the switch will be at the front of the saddle.

Part of the design change is because I still can't get those waterproof electrical connectors. I'm sure they will show up in three years, but they do no good before then. I found a friend who can get me some military spec connectors for $50, and I'm too cheap. So the design no longer requires them. The down side to mounting everything in the saddle is maintance. The plus is it will be more compact and it looks better.

1/12/05    

There is a certain feeling when you take a brand new $150 saddle, and stick a knife in it.

I hacked up a Bob Foote pedestal, and created mounting holes for the otterbox, pump, switch and outlet hose. Without those components installed, I seriously compromised the structural integrity of the saddle. When I put the parts in their places, the saddle firmed up again. I think once everything is wired and glued in place it will be solid once more.

The inlet for the pump is at the bottom of the saddle. I cut an 8" long by 2" high intake slot on each side of the saddle, leading directly to the pump, which is mounted in the middle. The outlet hose is slightly off-center, which lets me keep the bag cages looking straight.

I'm currently debating over bonding some of the items in with spray foam. When I hacked out the saddle, I left some voids where I cut too much here and there to get everything to fit. Right now my options seem to be spray foam, filling the area with GOOP, or trying Polyurethane adhesive. I know GOOP will work, but am tempted to experiment with the others.

At this rate, the system will be in place for testing Sunday. The boat may not have all the other outfitting, but it should have the bilge system. I'll post photos and other info when it's available.

1/14/05

I vetoed the spray foam. It expands for quite some time, and will throw everything out of whack.

Today I ran the wires, and started the wiring of the pump, battery, switch, etc.

To keep the battery from flopping around, I put some minicell foam in the otterbox. One layer sits behind the fuse, and another layer partially protects the fuse. Initially when I put the battery in, it became stuck. 20 minutes later I was finally able to remove it. Some additional shaving of the foam, and it is a snug but not impossible fit.

The hot glue gun has become my friend. That is a handy little thing to have. I hot glued the fuse holder in place, I hot glued the wires that come out of the otterbox, making them watertight. It works to quickly tack something in place. It's only downside is it can make a mess.

I'm letting some glue on cure on the electrical connections. Tomorrow I'll finish the wiring and test the pump to make sure it all works before gluing everything in place.

1/18/05

Success!

I've totally outfitted my Nexus, and am in the process of outfitting the Prodigy X. All the tests I have been able to do in the warehouse show the pump to fire hose water out the back. I have not given it a proper test in the pool, but on Sunday I will have all the performance measurements for both boats. At that time, this page will change to offer photos of the system, statistics, and all the other information people have been asking about.

4/24/05

Test Run was Awesome!

We ran the Prodigy X down the Eagle below Gypsum to work out the kinks, before going to Pumphouse.

The pump drained all but a small amount of bilge water. Running the macho routes, and being able to turn the switch to drain the boat before the next wave hit was incredible. It makes running rapids a whole different experience. You no longer have to worry about bailing, or trying to run dry. I hit a wave large enough that it chest slapped me, and the boat was empty before going into a huge hole just downstream.

At some point, I'll update these pages and show the photos and action shots of the pump in use. I have had several requests to install the pump in peoples boats, and I have to stress this is not a retrofit. As I have designed it, it cannot be added to existing outfitting. That doesn't mean you can't figure out how to add it, but I don't want to figure it out. I really like the pump under the seat, and the clean installation. A retrofit will look like a hack job.

5/27/05

I've forgotten about this page. We are working on a version that will fit inside a We-no-nah sliding pedestal. I ran Six Mile Gap in my Rendezvous and missed the flip a switch ease of this system.

The drain times on the boats vary. The Prodigy X has a rounder bottom than the Nexus and with the massive floatation drains very fast (10 seconds) and leaves very little water in the boat. The Nexus with gear takes longer, up to 45 seconds (much less with just floatbags) and with the flat surface will not drain as much as the Prodigy. Whereas the Prodigy may have less than a quart of water left (it's almost totally dry), the Nexus has about a gallon before it sucks air.

The silt on the Dolores did offset the balance of the Nexus pump. I haven't used it since that trip, but it appears the boat needs to be backflushed with clean water after too much mud gets sucked in. The solid hose used on the Prodigy also is more effective than the lighter flextube bilge hose used in the Nexus. The Nexus hose is half the weight, but I suspect silt and mud have collected inside it.

Both Bell saddles have split in the middle where the pump was putting pressure on the bond. I've re-glued it and capped the seats with Neoprene. They started to pull even when I was cutting into them, so I think it is an issue with those specific saddles and not necessarily the pump.

Battery life is impressive. I've been using the same charge for over 3 weeks on the X and the pump still blasts water. I'm not sure a solar charger is needed on week long trips except with serious whitewater. Getting 50 blasts between charges should be enough for most trips.

Thanks!

I would like to thank Dave Delano, who has provided me with some helpful articles and links to sites.

Article by Eric Nyre