Refurbished "SLA" with a special surprise inside

[creativeadapter1990]

Oddly enough a very wonderful suprise inside.
They ain't lead acid!

No, as far as I can figure these are AlMg/neutral/Fe2O3.

My first was a Deka group 24 I got for my trolling motor.
I had modded the motor to the point that it would plane my uncle's stillwater 17 with 4 people on board. The motor would be cool when removed from the water but in about 5 minutes out of water (not running) it would get uncomfortably hot and stay like that for over half an hour.
That one battery would keep it at full speed for over 2 hours and would have enough left to almost do it again.

The battery would take charge at 14.5 v and after a couple hours out of the charger would mysteriously climb to 16.8 volts as the spinel structure of the anode continued to recrystalize.
more detaills about the chemistry here: viewtopic.php?f=14&t=31544

This battery was stolen from the dock at walden pond in 2008

I just got my hands on four half- U1 size batts of what I believe to be this type and put them on my ebike. All four together cost me less than $300 usd
they say powersonic and "contains lead" on them but weigh far less than even a starting battery of the same size.

What I think the refurbisher is doing is using magnalium and Fe2O3 instead of lead and lead oxide when filling the grids, possibly for cost reasons.

I really wish i knew which refurbisher is doing this because I want to buy from them again.

My bike runs these batteries with a 12 fet infineon controller that has solid copper bus bars and copper wire embedded in the solder of the high wattage traces, the motor is a bmc V1.

in retrospect this may be a bit much for this little motor, anyone got an opinion as to whether a hubzilla is in order?

sorry for the extensive edit, my tablet that I started the post with was unable to scroll to the bottom of the typing area so I was unable to finish my post.

[goinmobile]

I'll bite.

You are planing a boat loaded with 4 persons with a trolling motor?

You are doing this with one battery for 2 hours?

At what speed does the above weight plane?

[creativeadapter1990]

6 or 7 mph with 4 people aboard, 10 mph with just me. Old Town stillwater 17 fiberglass canoe. with just me in at full speed more than half the boat is out of the water and the bottom oilcans with every ripple. When I go in the front to level it: wow.

At throttle 3 or 4 out of 5 depending on weight it will start acting stern heavy and will be tippier, this is about 5 mph.

Moves my 14 foot runabout at about hull speed, but those were normally equipped with a fastwin 18 or a bigtwin 30.

[goinmobile]

Tell us more on your refurbished battery & troll motor. This battery must have a higher C-rate & energy density than lithium.

Its hard to plane a square stern fiberglass canoe, I know 4HP doesn't work, but 10HP does. 2 4HP, one each side, does not plane with 2 people, 10HP does.

My experience with 18 footers is 2-3" of gunnel above the water line with 3 persons, 1-2" with 4 persons, get the hell out right now. Post photos of this feat please.

A planing canoe is not a comfortable ride with 2 adults on board, frequently capsized as the hull is useless on plane, doesn't steer, skitters instead. Be sure you have your plug wrench & spare fuel tank with you, or you'll be missing the evening bite.

[Jeremy Harris]

I agree, there's a hard, fixed, relationship between power, boat weight and speed (look up well-proven methods, like Savitsky's or Crouchs to get an idea of the power needed to plane a boat). I've played with a few trolling motors, even the biggest only puts out a little over 1 hp, plus they have small diameter props with too fine a pitch to go fast, they are optimised for pushing heavy boats slowly and not getting fouled up with weed too badly.

Last weekend the canoe pictured below, with about 2 to 3 hp of electric inboard power driving a fairly efficient prop of around 10" - 12" in diameter, managed to do about 8 kts with one person on board. It was a fair way off planing, as you can see; it was just part way up it's own bow wave and needed maybe double the power it had to get on the plane, I reckon, mainly because of the lack of planing area on the hull.

My own very light flat bottomed boat needs around 1.2 hp to plane at 9 kts, but that's with just me aboard (total displacement around 105 kg, or ~230 lbs). With four people on board it'd need a heck of a lot more power, but even with just me and a trolling motor modded to the point where the brush carrier was on the point of failure I don't reckon it'd plane.

[goinmobile]

I guess you meant to say pushing instead of planing. I've pushed a lot of water too in overloaded canoes. A canoe is designed to cut the water at slow speeds, not plane or speed with motors.

Jeremy, I was surprised that someone else noticed the air traveling down the back of the motor shaft & entering the propeller current, usually mistaken for prop caused cavitation.

I found my lowball Minolta ran best with an inch of prop out of the water & about 70% throttle. Speed was about the same as full throttle with the motor & tube extended into the water, trying to defeat the air caused cavitation. I guess 20-30% more efficient on mileage, maybe 5-10% greater speed.

The most efficient electric drive will be a straight shaft, prop on one end & the motor on the other. This eliminates the loss of your 90" gearing of your build & a good deal of the motor shaft drag as it angles in the water. Math may prove otherwise on the shaft resistance as more shaft is in the water, lets say at a 30" angle. This mounts oarlock style & can swing in any direction within reason, eliminates the scag leg for steering too. The shaft can be 10 feet long.

CA1990, Your link to this battery chemistry reads like science fiction, & a mysterious military link. If the chemistry & capacity are true & its military use, then its very unlikely to ever have been in the public domain. You said this came from a university, so there is a tech transfer process involved, not random marketing to a fraudster.

Were did you buy your current refurbished "surprise" battery? How did you determine/guess the chemistry if its in an SLA case? How can anyone refurbish an SLA case?

[liveforphysics]

The odds that battery is anything other than lead are extremely low, and if they are, and it wasn't labeled as such, it's extremely bad practice and dangerous etc etc.

If your batteries are super light, they just skimped on the plate count/thickness in the refurb process.

If your charger pulls it to 16.8v, time to get a better charger that would shut down in a fault condition like that. When a lead acid battery pulls that high above the electrolysis point, it typically means the plates are packed with little bubbles forming a near-insulating layer on the surfaces of the plates.


A boat could carry a thousand people a thousand miles with any trolling motor, or no motor at all if the boat is drifting in the current/wind.

[creativeadapter1990]

"If your charger pulls it to 16.8v"
It does not.
It charges to a little over 14 volts and AFTER removing it from the charger it then climbs from 14 volts off the charger to a final open circuit voltage of 16.8 over a few hours.
under a 30 amp load it drops to 16.2 volts

I bought the original boat battery at bedford auto parts, who has since moved to a different brand, and I bought the ebike 1/2 U1 batteries at Keystone battery in Woburn, for $53 usd apiece. They were under the impression that it was conventional sla, which is why I used the word "surprise" in the title of this thread.

The canoe (more like a piroque or a low sided dory, it was flat bottomed, beamy and had very little rocker, and was not a squareback) was an absolute bitch to operate at those speeds. It's nastiest habit was it would swerve dangerously in the opposite direction I was trying to steer. It was drawing about 4 inches if that and the gunnels were far enough above water to make it thru the Nauset Marsh inlet at 4/5 throttle completely unscathed.

Testing ended after the thrust made a small crack in the side of the hull while attempting a tight turn and my uncle (the owner of the boat) told me I wasn't ever allowed to motor it anymore. This is a 20+ year old fiberglass old town and not one of the featherweight models.

The battery technology may seem bizzare or exotic but it really is no more complex the advanced nizn types used in early evercel batteries. It is simpler than nimh and certainly lithium.

How I suspect they made them is by taking off the shelf electrode grids slated for lead acid and filling the anode with magnalium and the cathode with iron oxide, and using a suitable replacement electrolyte. Not knowing what is actually used the most likely candidate I can think of would be an aqueous solution of an alkali metal tartarate as they have been used in hard anodizing baths (extremely different from conventional acid "soft" anodizing) at up to 180 volts per cell

[Jeremy Harris]

The most efficient electric drive will be a straight shaft, prop on one end & the motor on the other. This eliminates the loss of your 90" gearing of your build & a good deal of the motor shaft drag as it angles in the water. Math may prove otherwise on the shaft resistance as more shaft is in the water, lets say at a 30" angle. This mounts oarlock style & can swing in any direction within reason, eliminates the scag leg for steering too. The shaft can be 10 feet long.

I lose a measured 4 watts at max power in the right angle drive, and gain around 6 watts worth of reduced drag from the exposed shaft I'd have with a long shaft drive over the drag of my streamlined leg, plus I gain by having the prop thrust vector aligned with the direction of travel, which gets me another 4 or 5 watts gain over an inclined shaft. No gears in my right angle drive, just a double universal constant velocity joint running in a 10W synthetic oil bath. There were plenty of long tail drives in the race - I was faster than all of them.

I was putting between 800 to 1000 watts into my motor, the total boat weight was about 105 kg with me in it (so about 230 lbs). It was a flat bottomed canoe/pirogue shaped hull, that was drawing less than 2" of water when not moving. No way on this planet would it have gone as fast as it did with ANY trolling motor made. They simply aren't capable of running at high boat speeds, as they have a fine pitch, small diameter prop that's designed to push a heavy boat slowly. They run out iof thrust at around 5 to 6kts, just from the fine pitch of the blades.

[dnmun]

this place is like an amuserment park

"battery technology may seem bizzare or exotic but it really is no more complex the advanced nizn types"

"Testing ended after the thrust made a small crack in the side of the hull while attempting a tight turn and my uncle (the owner of the boat) told me I wasn't ever allowed to motor it anymore. This is a 20+ year old fiberglass old town and not one of the featherweight models."

what's a small crack among friends? it's just a boat.

[goinmobile]

Fess up & tell us your purpose as you well beyond exaggerating.

Are you an author? Don't know the technical so post in forums? Do you want help that won't blow your cover?

You have had 3 experts on each topic contradict your claims: battery, power & canoes.

Don't go away mad, tell us your issues. Someone to everyone may be able/willing to help you. Best wishes, Bob.

Jeremy, I'll get to your topic to comment on rigging, I confess to not reading all of your motor leg mod, thinking it was geared, clever improvement as usual.

[creativeadapter1990]

The ebike batteries being of the type was a false alarm.

It turns out the higher than normal voltage on my bike batteries was an measurement error caused by a the cheap voltmeter built into the battery charger.
It indicates 13 volts for each block fully charged, which is very close to an external voltmeter reading I took.
wiring the four of them in series indicates 58 to 60 volts on the charger's voltmeter and the external voltmeter gave me 51 volts.

The inability to drive 50 miles even while averaging under 20 mph would seem to indicate that the advertized capacity of 21 amp hours is certainly not being exceeded.

The ebike batteries are plain ordinary lead acid.

The boat batteries are perhaps not a false alarm.

I charged them again after a boat trip.
I currently have refurbished "proprietary electrolyte" deka group 31 floodies to power my boat.

The battery charger, a mastech industrial multichemistry adjustable rate SCR smart charger, has settings of 1, 2, 5, or 10 amps nominal rate, a bit of a misnomer because it is does not use a constant current charging regimen.

They have such little internal resistance that they pull over 10 amps when deeply discharged and the charger is set to the 2 amp rate.
Charging ends at 14.5 volts, confirmed by two separarte outside voltmeters.
after being removed from the charger the voltage increases over a few hours to 16.8 volts.
After 30 minutes of 30 amp discharge the voltage is 16.3 volts open and still over 16 volts with a 30 amp load.

The trolling motor was tested again on a more normal canoe hullform, a 19 foot grumman squareback and failed to plane even with just one person aboard. in this case the abnormal factor was an unusually efficient boat. My modifications improved it a fair amount, it is now probably one horsepower instead of one half, it has proved itself less powerful than honda's little 2 horse aircooled fourstroke.

As anyone who read the thread i linked to in the original post will notice, I have had to fill in a lot of missing information regarding the chemistry.

The originator of the modern aluminum iron oxide battery is Prof. Ehsani of Texas A&M university.
I found this interesting article: http://groups.engin.umd.umich.edu/vi/w2 ... ani_w2.pdf
What is most relevant to the discussion at hand starts at page 61.

He does not ever claim use of heavily alloyed aluminum anodes in this publicly disclosed paper, and once uses the phrase "pure AL"
If he were to actually use straight up aluminum and an alkaline electrolyte, the battery would not be rechargeable because the aluminum upon oxidizing would quickly become aluminum hydroxide. Such a battery was briefly mentioned in the 1920s and quickly written off due to this flaw.
Being that the research was intended to develop a super battery for hybrid trucks it would be expected that there is a desire for a rechargeable battery with some hope of a long cycle life.
He throws in a hint by choosing O instead of OH as the preferred transfer ion. This would suggest a neuteral or acidic electrolyte.
The use of an aluminum-magnesium alloy was independently thought up by me as an educated guess attempting to reverse engineer his claimed results. Even in this professors other writings on this subject, now long removed from the internet for copyright infringement, never explicitly mention magnalium. Several researchers at the same time and also in the US tried to add small amounts of gallium and zirconium to the aluminum anode but failed because they either did not add enough or if they did the metal reacted with the water in the electrolyte before the battery had completed even one full cycle.

I was considering applying for a patent but Dr. Ehsani has very powerful prior disclosures and my adapting the spinel anode alloy technology from calcium zincate (used by evercel and evionyx) to aluminum spinel would likely fall under the "obvious derivative" clause for denial. I would like to argue that but there are various reasons I can't. Some of it is I can't afford a good patent attorney and some of it is I will be damned if I let a chevron/cobaysys incident happen to me like it did to Ovshinsky.
I know how these sort of things work and if I sell the patent to a battery company some fossil fuel interest will buy it off them, if not buy the whole company, then make and patent little tweaks to hold on as long as they can. My soul is worth more than a few million dollars.