magnetman

Well spotted ! Its interesting that they would put such widely different specifications on what would initially appear to be quite similar batteries. I don't know if it is some sort of odd marketing thing but it is good to know about it.

It might a different Boat but it does ring a bell. Would have been 2 or 3 years ago. There wll be other old wooden wrecks with 4LWs in them. It was on the hardstanding not in water.

I remember the Boat on eBay a while ago. It sold for about £600.

Good point about the hazard. its early in the season. I think its quite likely there will be another significant flood event this winter. Big ones seem to come in January and its only just the beginning of December. The ground is prepared. Like a soggy sponge. Air bags seem to be the answer for most of these things. I imagine there will some people looking for good places to record a video to their phone from.

A slitting disc will go through a stainless shaft pretty quickly. I've done a couple of 1.5" stainless shafts in the past it was like a hot knife through butter. Gloves and eye protection and don't have your face in line with the wheel. I like to hold the grinder well over to the left with right hand on the side handle and left to hold the switch then if anything happens its away from your important bits and protected by the shield and the motor casing. Recipro saw would be another option but you can't beat slitting discs. Marvellous invention.

The Boat is on the bank and draws at least two feet. Groove irons don't go that high up above the towpath. The curve of the bridge would not allow it even if the towpath side was extended. It might be best to just wait for the next flood event. Last winter was the second wettest in the Thames catchment since 1871 so if we get a wet winter this type of thing is going to happen again. Charwell is a Thames tributary in fact one of the largest. Check the water situation reports.

Do you actually want to fully charge? I was under the impression that it was better to not fully charge Lithium batteries as it chemically stresses the internal structure. Maybe this is erroneous. I would welcome correction. Of course it doesn't really matter how long the cells in a packaged battery last as the internal electronics would probably pack in first anyway.

I suppose my analogy is a bit naff because the glass would overflow ! But they don't need absorb and float. They just need charge. Energy in up to a certain voltage. Once they get there thats it job done. Uniform input. And I do now think the LTO behaves completely differently anyway.

I have not done all that many experiments and my main bank is Lithium Titanate which may behave differently to Lithium Ferrophosphate. It seems to me that Lithium batteries behave like a glass of water. You pour energy into them up to a certain voltage level then they stop accepting charge. There is no Bulk, Absorb and Float. Its basically just filling a glass.

Its all about the knees. If the cells are in the knee areas they are chemically stressed. The knees are where the voltage rapidly changes in the charge/discharge curve. so the upper is about 3.4 which is *4 so that would be around 13.6v. Much lower than anyone selling a battery is going to recommend but it might result in the thing lasting a lot longer. Small loss of capacity per cycle but possibly many more cycles as it avoids stress. Marketing is important with these products because virtually everyone using them is replacing an existing lead acid battery installation.

Should be ok then if there is something around 14v without an equalisation phase. There are various different arguments about what voltage LFP batteries should be charged to. For marketing purposes it is useful to suggest 14.2 or 14.4 as that is the same as lots of hardware made to charge lead acid but if you can some people advocate charging to a lower voltage to avoid stressing the batteries.

Do your chargers have adjustable settings ? Maybe there are some DIP switches for this. It seems a bit old to be directly suitable for Lithium but there might be a Gel battery setting which would be similar. Worth having a look at the manual I think.

It might be a bit naughty if the Sterling Pro Digital chargers have a Lead Acid battery equalisation program built in. I don't know how these particular chargers work but I think some of the older 3 stage chargers did have some sort of built in calendar thing which would automatically whack the voltage up really high from time to time. Might be worth checking. Obviously the BMS would cut out to protect the battery but going up to BMS high voltage cutout is not ideal.

deliberate flooding is interesting. I wonder if the CRT are legally allowed to do that. The stop plank groove irons at a bridgehole would not be high enough. The Charwell went completely mental in this event.

It looks like the footpath is still being used unless that is a previous bypass from when the water was only just over the towpath. Seems odd. or more likely 'was' being used until closed. It does seem to be teetering and it looks like a piled edge so it would probably tip right over. Winch from the other side is the way to do it but will it come back up is obvious question :unsure:

I remember the one you mean. It rolled over and sank. However it then got pumped out and removed so the job did get done. The green Boat in the background looks very low in the water I wonder if that is normal or if it got caught as well. Maybe just an odd one it does seem to have a tall cabin.

Interesting situation. I wonder if it would self-right if it was pushed or pulled over. Probably not. Air bags maybe? Interesting elfin safety risk assessment.

I get around the fridglessness food poisoning by shopping every day but then I am not working due to early retardment. It is good to have plenty of power. I have a fairly large bank of LTO (,approximately 400Ah at 15v) but that is because I could not refuse the offer and my only power source summer and winter is the solar panels. But yes a larger bank to allow longer gaps between charging is definitely nice.

@blackrose why do you need such a large battery? It is worth remembering that with LFP batteries the Ah rating is not really the same thing as with LA batteries because you can use more of the capacity. I don't know what the exact figure is but with LFP batteries you can charge and discharge between 20% and 100% (BMS protected) several thousand times whereas with LA batteries it seems to be a bad idea to take them much below 50%. So couple that with the fact the battery will charge much quicker and you might only need half as much battery as you would if it was LA. I imagine you know all this but it is still interesting. If you are running a generator regularly in winter anyway it seems to me that a smaller battery might be appropriate.

There is some confusion in the part you quoted. Carers allowance is paid by the DwP. I'm just idly wondering here if the OP could potentially apply for reasonable provisions and a limited cruising range from the CRT because of being a carer. If one is receiving carers allowance there is a requirement to be looking after someone for 35 hours a week or something like that. That is going to mean geographic restrictions unless the person you are looking after is traveling with you on the Boat. There are quite a lot of people who do apply for reasonable provisions but I am not sure if being a carer is one of the criteria. It might be worth asking then if successful just do away with the mooring altogether.

The Valence batteries are not ideal for my use as they are only rated to IP 56. I think these batteries have internal electronics so I suspect if they are used in damp environments there may be some potential for problems. The electric launch I need a battery bank for is an open Boat. I think this might be why these batteries are cheap. The LTO batteries I bought from a friend of James are brilliant but he hasn't got any more. Fogstar batteries are IP67 which is certainly better than IP56 in an open environment.

Yes I know. He told me a couple of days about them. I may consider them.

Definitely a better name. Does it do more than you need ?