...but aren't all these claims sort of subjective. For instance, isn't battery use (or charge) really a function of how dry you paddle. Say for instance I'm running the Ocoee and never turn on the pump, while Mary-Ellen-Jones leaves it on practically the whole way down. As for how fast a particular pump might empty, that would seem to imply no more was being added. But more importantly, a question of how much flotation is in the boat. Again I'll consider myself (as I'm sometimes - aware of what I'm doing) . In this case I hardly ever blow my air bags tight, and never over the top of my gunwales. Usually keeping the same air, so they'll re-inflate nicely for the ride home. So if Bob-lee-Billy keeps his bags blown tight, throughout the whole day (and has longer airbags and more foam). Would it possibly affect how much water, and hence how long it takes to empty the same canoe. Another thought, would factors such as impedance affect performance. By maybe decreasing available power, or requiring more power for the same function.
What I'm really asking... (all kidding aside)
Has anyone actually has tested their flow rate, versus a pumps advertised rate. Like maybe timing a known quantity of water.
And has anyone subjectively compared power consumption? Not sure how to?
philcanoe wrote:
[*]Has anyone actually has tested their flow rate, versus a pumps advertised rate. Like maybe timing a known quantity of water.
Yes, sadly enough, I have.
At 12V, attwood v1250 pumps about 650 GPH with 18 in. of head. Not sure how that compares to the spec since I no longer have it, but my guess is that it is low. It was pulling about 2.4 A at 12 V.
At 13.6 V it pumped about 900 GPH.
philcanoe wrote:
[*]And has anyone subjectively compared power consumption? Not sure how to? [/list]
Power consumption is VxA, so at 12V, your pump was
running 28.8 Watts. If you have a 2.4Ah battery at 12V, it'll go for an hour (no brainer) it's more helpful to know what current you are drawng than actually calculating power.
It's not really a no brainer that a 2.4 Ah battery will run an hour at 2.4 A. Many battery manufacturers spec Ah differently - and SLA batteries in particular, are terrible at discharging at high rates. Many SLA manuf. will spec Ah at C/10 or C/20 rates --- and not 1C rates (sorry for the EE nerdspeak).
For example, my 3.2 Ah SLA battery from batteryspace.com will last about 45 minutes at 2.4 A according to the battery discharge curve that they spec(http://www.batteryspace.com/prod-specs/LA-12V3.2.pdf). But if I were to discharge at a very low rate, such as .15 A, I should get the full 3.2 Ah. Best to look at that actual discharge curves of the battery spec than assume you will get the full Ah rating.
I dont even waterproof anything except the switch. But then again I'm el cheapo. The setup works great, I have it in two boats. The battery holds a good charge and is usually good for 3 days.
You can go the fancy route with the through-hull, but i just have the discharge hose zip-tied at the gunnel. The great thing about this waiting in an eddy shooting your buddy in the face as he pulls in. Just hold thumb on end of hose and aim.
kslund, I'm a fellow EE nerd, so no apologies necessary! Hadn't thought about how non-optimal batteries get at higher currents... I tend to think of them as special capacitors. I'll be headed back to school for power electronics in the fall, so good to get the brain moving now! I'm assuming that flatter discharge curves are another advantage of NiMH and LiIon batteries?
I copied Bob Britt's battery setup for my dad's boat. I used a Pelican 1010 case and 14.8V Polymer Li-Ion battery (4.25 Ah) from BatterySpace.com. It was not cheap, but it weighs under 2lb and drives his Tsunami 1200 nicely.
I'm using a Pelican 1030 case and a 12V NiMH (5 Ah) battery. My battery weighs just over 3lb, and cost about $100 less than dad's.
Shep, I am no expert when it comes to batteries. More like chemistry than electricity to me.
I'm not 100% sure, but I think you are right that Li and Ni batteries have a flatter discharge curve and are not as prone to the same reduced output problem as SLA+high discharge. I have no idea why this is - just basing this on observations of several battery datasheets.
Good luck on the power electronics! Promising field - especially alternative energy I would think.
Oh, and my setup is alot like swimmingmexicans. Pump sits behind me - SLA is strapped to the back of the saddle on top of the pump, output tube is simply run over the gunnel and zip-tied to the thwart. I bought a 3 dollar switch from ACE hardware, put a rubber boot on it, and then dipped it in 3M marine adhesive up to the boot (the white goop - comes in a red and white tube). The switch is duct taped on the thwart right behind me on my offside. Nothing is waterproofed but the switch. This is by far the simplest setup I've used.
I would like to get a lighter battery, but I don't want to deal with waterproofing it (pelican case, etc...) As far as I know, SLAs are the only that are good to be submerged in water - anyone have different experiences with Li or Ni batteries?
i have 2 of walmarts 800's in my zoom.. they work well in my nitro too. i use a 12 v 6 amp battery w/ 2 5 amp fuses. the baterry weigh's about 3.5 lbs. but actually helps a boat right it's self after flooding. i had the batteries shop fix me up a charger for 10 bucks. the best aside from this set-up i've found .. is the tsunami w/ a solar panel. money being no object , guy sells these from a web page for about 150.00 bucks if i read it all right. pretty cool 'cause u can take a few days trip w/ out having to recharge ~
If "money is no object" you could get a lithium ion battery made for your pump set up. More complicated to make yourself, but more power and longer lasting as well as much lighter and smaller.
jatakasawa was asking about hose. RV dealers stock some, in various diameters, which is flexible, but rigid enough not to kink.
As far as complete kits, for those who don't wish to run around matching up random partz, check out www.rapidrunnerbilge.com. They make state of the art systems, which are, admittedly, pricey (but good!)
I got my hose at a marine store. I'm glad I lucked into stopping by. The hose is nice and light and thin walled so it doesn't stick up so high above the gunnels. It seems to be more or less specially made for bilge pumps. I'd check out a boat shop if you have one nearby.
So the pump-making experience has been all hassle and no fun thus far. Dropped 42.00 bucks at Wal-mart on an Attwood pump and Attwood brand tubing. Dropped $113.00 at radio shake on a switch, battery and battery charger.
The pump is all hooked up and works great! But Neither Radio-Shack nor Lowes carries the little rubber boot for the switch. Then, after I'm ready to test it out, I discover that the tubing (which was sold right next to the pump and was the only tubing available) has a much smaller diameter than that of the spout on the pump. So needless to say, I couldn't exactly test it out.
The icing on the cake is when I searched the house for my waterproof box that I've had forever...and the one component to my system that I didn't need to buy, only to discover it's lost. Not in the car, not in the boat, not in the garage. So I now have to buy that.
So, I've now dropped $155 and still need a box and a boot and maybe a thru-hull although some of the posts above are making me second guess that.
They sell pump kits online for $159.00 plus S&H....and I'm beginning to think that they're worth it. But I'll still come out ahead due to the battery charger that I believe is not included in the kits...although I could be wrong.
I love canoeing...but I really hate working on the boat. Straps, bags, pumps....I wish I had the loot to let a pro do it all for me. Pure hassle.
I'll be headed back to school for power electronics in the fall, so good to get the brain moving now! I'm assuming that flatter discharge curves are another advantage of NiMH and LiIon batteries?
