Soldering re-chargable cells.

[T i m]

The boat already has one from the builder but doesn't need any others (regarding the electric propulsion) because none of it is permanent.

Not really an issue in an open dinghy. ;-)

Yes, especially with a wet / flooded battery and conventional (non recombination) vented caps. And also typically only when there is excess (or too high a level of) charge and the surplus energy is dissipated by 'gassing' (liberating hydrogen). Again, as I won't be charging the batteries in my 3m folding dinghy and the batteries don't have flooded cells but the electrolyte held in solid suspension in the form of a gel (to a level where if you smashed the bottom corner off the battery, *no* electrolyte would leak out) ... and the caps recombine any gasses liberated by any overcharging and convert it back into a liquid (not that there is any in these gel batteries and they are 'electrolyte starved' ...) I think I should be ok. ;-)

And that should be just as well as they are typically what you find in most mobility scooters (except those now going over to Li-Ion).

Yup, been there and done that (as a kid) but I was doing all the things you shouldn't.

Even my chargers are 'spark free' (intelligent) but even though they are I still turn them off from the wall before disconnecting the leads.

Now, you could smell when the 8 x 200Ah 6V traction lead (wet) acid batteries were fully charged in my electric Moke from quite a way off (downwind). ;-)

Cheers, T i m

[T i m]

FYI (&FWIW etc):

By 'electrical system' they say they mean 'permanently fixed', as in a cabin cruiser etc, not just a battery connected to an outboard motor.

FWIW, all my systems are all protected by both a resettable fuse and a two pole disconnection (Anderson SB50, just outside the battery boxes).

If all else fails it can be thrown overboard and unlike Lithium, that won't make matters worse. ;-)

Cheers, T i m

[Brian Gaff]

More so. Assuming of course they have no tags for the purpose. The power density of Li is greater and although they are designed to run hot, localised heating is not a good thing. They can tend to cause a fire if they short internally.

Brian

[Brian Gaff]

Hmm, Well you seem to be the lucky one. I suppose its all about minimising the physical and heat induced stress. I don't know how mechanically solid they are, but one needs to avoid use of an ordinary vice. A circular or whatever shape the cell is, clamp holding over a large area would seem to be best. Li batteries came out after I lost my sight, so I only have other peoples experiences to draw on there. Brian

[Thomas Prufer]

I treat batteries with a lot more respect since this happened:

Diesel automobile, drive, stop to fuel. On restarting, the battery burst... top completely off, four sides petalled, . Acid everywhere! A check in the shop showed the charging system to be ok. Thoroughly rinsed "everywhere", fitted new battery, ran as before for years.

So when I charge even a small (say: 6 Volt 2 Ah gel cell), I put it where it bursting, leaking, or dribbling acid won't be more than a nuisance.

Thomas Prufer

[dennis]

Sounds like you are to me. I want a subsidy from others so I don't have to pay as much is pretty much the same as harry IMO.

The big difference is that the government wanted people to do what harry has done, they don't want you to have a boat.

[Peter Parry]

Luck has nothing to do with it, just a sensible approach to the problem.

Correct, the abrasion and cleaning of the contact area together with the use of a non corrosive flux, tin/lead solder and a big hot iron means the solder joint is made quickly and reliably. Cooling quickly afterwards minimising heat stress within the cell. Don't forget these cells are generally rated for up to 80degC and soldering will take them nowhere near there. The risk is not heat degradation of the cell but possible damage to the base insulator and top sealing plate. This risk is minimised by making the joint very quickly and cooling it quickly.

As most people don't have three hands the "clamp" is only to hold the battery in position while you solder the wire to it, its usually nothing more complicated than an elastic band and a few scraps of wood.

[Dave Plowman (News)]

My thinking too - but for a much loved 18v drill which has a right angle attachment. So not easy to just buy new at a reasonable price. I have three batteries, and two are dead. The third was re-celled professionally, but doesn't work as well as a OEM one did - in terms of maximum drill torque.

My vaping device(s) use 18650 and they are very good value for their capacity, and being smaller than NI-Cads would fit inside a battery pack easily. The charger would obviously require modification too.

[T i m]

Well, it might to you because you are easily confused. I'm going to take my batteries round to harry's anyway so he can charge them on his panels, as I'm already paying him. ;-)

Of course it is (to you). There is a massive difference between forcing other people to pay for something that you use AND GAIN FINANTIALLY FROM personally ... and off-setting the (in my case 'arbitrary) cost of making use of an existing recourse because of the benefits my use will bring (and many of the waterway authorities seem to agree because they do reduce the licence fee for those who don't pollute the water and air (fuels and oil in the water and fumes and noise in the air). Similarly I don't use many of the services the licence helps support, like pump-out, hard moorings, water / electric hookup or even locks for that matter (as we can portage round).

Part of the licence fee will also be used to 'clean up' the pollution made directly into the water by spilt fuel, leaking oil or underwater exhausts. I won't be doing any of that and I won't be using the waterways any differently than those who row (at the point of use etc). Many authorities do indeed treat electrically propelled boats in the same way as they might sailing or rowing craft or at least reduce the cost.

"The Authority encourages more environmentally-friendly forms of boating with reduced charges for electrically propelled motor craft."

But all under false pretences and using questionable ethics.

Of course they do. We are positively encouraged to make use of the facilities open to all of us (not just those who happen to own a roof that faces in the right direction and are looking for a cash cow).

'Use it or lose it'. My licence also helps towards the upkeep of the towpaths but I haven't seen a horse drawn boat on any waterway for years and the walkers and cyclists (who create most of the wear) contribute nothing (but I'm happy to subsidise them). ;-)

Cheers, T i m

[T i m]

I bet and an issue with flooded cells (as opposed to electrolyte starved AGM or Gel).

How old was the battery OOI?

So no spontaneous fire then?

If it's a proper 'gel' battery there should be any of that under any circumstances (however, some manufacturers incorrectly mark their AGM cells as 'Gel', and whilst there is a slightly greater risk of electrolyte getting out, there isn't very much of it as it's 'absorbed' in the glass mat).

Anyway, my comparison was really the RW risks of LA versus Lithium, especially Li-Po and also including Li-Ion.

Plenty of videos online of perfectly healthy Lithium cells spontaneously combusting simply due to overcharge or previously being damaged. Not something most LA batteries will do.

Like I said, I'm not (and never have) said their are no risks in any energy storage technology, just that there are some that are naturally more volatile than other and especially if you put them in contact with water. ;-(

Cheers, T i m

[T i m]

And you might need a Battery Management System, a PCB that manages the charge, cell voltage balancing and over discharge protection. It's the small PCB you find in all such battery packs (like the portable phone chargers, laptops and Li-Ion drills etc).

That's not to say you can't do without a BMS (many geeks do) but you then need to hook up a suitable charger to managing the charge / balance and some form of cutoff or alarm to manage the over discharge.

That's why many Lithium powered tools just 'cut off', rather than gradually slowing and stopping as with Nicad or NiMh etc.

Cheers, T i m

[Thomas Prufer]

The battery hadn't had water added in at least the past months.

A few years. This was a diesel starter battery, and was useful in the previous winter.

No.

The AAA man said that bursting batteries happened off and on, usually due to the charging system being defective and cooking the battery at 16 or 18 Volts. He'd previously never seen it happen on a correctly working charging system.

I just place the charging batteries a lot more carefully than previously.

I have friends that use Lithium batteries in their motorbikes. It saves a lot of weight, which is great on a racing bike, and makes sense if you've also laid out on the titanium exhaust and whatnot. Downside is the price, they are

*expensive*!

Thomas Prufer

[Fredxxx]

An internal short from a distorted plate is all that is needed. A good reason to avoid using undersized batteries.

There is no reason why a 'fire' should break out, once the gases have been consumed in the explosion.

[T i m]

Sorry, no, there are 'wet' cell lead acid batteries and AGM / Gel / sealed where there is no opportunity to add (distilled) water.

Ok.

Ok. ;-)

It can also happen if an internal cell link had eroded away (and / or fractures) and causes a spark just after the cell has been charging for a while.

Agreed and about the only time they are of a direct advantage IMHO. ;-)

It's the same with my electric outboard project. Going to (say) Li-Ion would save a lot of weight but with a lot of extra cost, not just in the battery itself but the power and stability of the chargers, given most people wouldn't want to 'sit around' supervising their batteries being charged. Plus the intermittent usage pattern adds to the unsuitability of Li for my needs.

Yup, in the most part I see that sort of stuff as just bling (on road bikes etc). e.g. If you are using the bike regularly and the battery and charging systems are correctly proportioned and matched to the charging system then there generally isn't an issue. Leaving a LA battery uncharged causes it to sulphate and then you just end up with a 'dead' or weak battery. Lithium can suffer neglect similarly and most have to have some form of BMS (built inside what looks like a traditional battery case etc) and so you then have the extra complexity of that (MTBF), plus the potential of a charging system that isn't correctly matched to the battery. ;-(

Indeed. However, with Tesla and the Chinese ramping up their Lithium battery manufacturing, that should improve in the future. ;-)

Lead acid does seem to suit more of a binary system, where it's either fully charged or flat (50% DOD) and can be charged and left (fully) charged ready for use. Li OTOH, if to be left for a prolonged (?) period needs to be put into a storage charge level and maintained at that level, so never 'ready' for instant use.

Like I said though, I'm still keen to give Li-Ion a try, even if only for the S&G's. ;-)

Cheers, T i m

[dennis]

You are gaining financially if you don't pay as much.

It does appear that way now but not when it started.

[T i m]

And with a Lithium cell they can spontaneously combust simply done to impurities in their construction?

With a lead acid, agreed. With Lithium the Internet is littered with cases where fires have broken out and peoples houses and cars have been burnt out. It's not the battery that burns the house down, the battery is a source of ignition (sometimes completely spontaneously) and that then sets fire to something else.

How many people have got away with just burns to their clothes or scorched holes in / on their furniture because their phone or vape battery has overheated and self combusted?

Galaxy Note 7 anyone ... hardly cheap or nasty as things technical go eh?

I've probably played with and used regularly more lead acid batteries than most here (200Ah x 48V worth in my electric car and regularly racing LA based vehicles plus all the standby batteries from a commercial telephone exchange, not to mention using them portably for charging RC cars and camping etc) and whilst my observations are just a sample of one, I don't know personally of anyone who has had a LA battery do them any harm but know of one person personally who would not have a house now, had he not been lucky because of LiPo fires (and he personally knows of several others who have seen Li-Po batteries go up in flames).

Again, I'm not saying LA is without risk, just that historically the risks have been pretty low and the consequences restricted to a very small radius.

And given how long the lead acid battery has been around (they were powering EV's at the turn of the century), it's no wonder they are still the std issue in most motorbikes, cars, trucks, caravans and boats (SLI) etc.

Cheers, T i m

[T i m]

You are talking bollox again. ;-)

Not paying as much means just that. You aren't adding anything *extra* to the pot, you just aren't taking as much as you otherwise might.

I thought that when it started. Anything that is fundamentally good / sound will generally stand on it's own two feet.

Cheers, T i m

[damduck-egg]

Generally Horses are prohibited from using most canal towpaths so using a horse drawn boat to navigate everywhere would be awkward. There are exceptions , some sections of towpaths have been incorporated into bridle paths and there are a few horse drawn tourist/ trip boats that have been granted the right permissions for use of a regular section. There are often complaints from the horsey community that this is so and they frequently wail that the Towpath was built for horses. Ignoring the fact that the horses were not being ridden and proceeded at a gentle pace operated by people who knew that for the system to work a degree of cooperation was required with each other aided by the fact that canal towpaths then were not legally accessible by the public. Now there are with all sorts of users the last thing needed is the towpaths being cut up by horses hooves from gaggles of teenage girls and their mothers pushing their way past other users.

G.Harman

[charles]

easy; make the towpaths only for Shires & Clydesdales.

[T i m]

Ok.

Quite?

Ah.

Quite. Thanks (as usual) for the background. ;-)

Cheers, T i m