T1 Terry wrote: ↑Thu Oct 26, 2023 9:33 pm
The article of 48v systems looks interesting, I'll have to find some time to read it through and digest it, but it could be an interesting move away from the traditional 12v. It does have it's own issues, inverters must have a pre charge circuit for one, the inrush current will vaporise a piece out of a battery cable lug if you attempt to simply bolt the cable to the battery ..... touching between the positive and negative has virtually no affect unless you have wet hands, but 48v bits Switches have issues with the higher DC voltage, they tend to arc across the contacts and either stop working or weld themselves closed so you can't turn them off .... and a few more issues as well
T1 Terry
Well, I read through the article on the "48v revolution" and there was no explanation of why? We were already building 12v and 24v systems that could and did deliver all they claim the 48v system is designed to achieve ..... they completely missed "the elephant in the room" how do you charge it from the vehicle while driving?
My guess is they are using batteries that are limited in their continuous discharge ability, so by dropping the demand per battery by spreading it across 4 batteries in series, they avoid the high discharge current problem .... better choice would be to use better quality cells in the batteries
My interest in the 48v battery system was combining a hybrid drive for a motorhome so the same battery pack supplied the energy storage for all the requirements .... it could also double as a starter motor for the engine and the engine/electric motor would provide a very high output generator for battery recharging if needed, along with the solar and regen when slowing the motorhome down rather than wasting all the energy as heat in the brake linings ...
T1 Terry
A person may fail many times, they only become a failure when they blame someone else John Burrows
Those who struggle to become a leader, rarely know a clear direction forward for anyone but themselves
Discovered today that my 19 year old 12v portable lifepo4 pack, has lost around 10% capacity and that's since the temperatures here have dropped. It's gone from around 22 most days with nights around 16, to days 13-15 and nights, 6-8. Have put it on the charger and will take it to 14.4v and see if that brings it back up to close to 100%, but doubt it after so many years and the usage it's had.
Also checked the spare cells same age that haven't been used or charged and they have dropped from 3.2v per cell, to 3.16v. So it looks like after almost 20 years they've started to deteriorate, but will do some experimenting with the cells as well and see what happens
I still 4 of the original cells I bought from Trev back in July 2011, they were new old stock so 4 yrs or so sitting on the shelf. So, I guess that makes them 18 yrs old, but in service for 14 yrs as a start battery for the EB Falcon , winch battery on the truck, the gypsy trailer, start battery for the 680 cu in diesel truck engine, half the start battery for the Hino ..... it's had a hard life I think one of the cells is getting a bit weak, had a battle winching the Lexus onto the truck a few mths back, still working fine in the Prius as a start battery, used it about an hr ago after sitting for a mth or more, so still holds charge, but I don't have any method of loading the battery for the 2 hr 50 amp load test to see what the capacity is now .....
The 600Ah in the Winnie are Sodium Ion, it will be interesting to see how they handle the tortures of a serious house battery, powering a 5kva inverter as well as all the 12v stuff .....
T1 Terry
A person may fail many times, they only become a failure when they blame someone else John Burrows
Those who struggle to become a leader, rarely know a clear direction forward for anyone but themselves
G'day NP. What have you been up to? Sidecar finished?
All the people that I know that went down the Lithium road many years ago are still very happy with what they have.
I'm not so sure about all those that just went to drop-ins though.
There are a lot of 'lithium experts' now on various sites that argue about how it should be done, but don't really understand what they are saying they do.
It will be interesting to see how T1 goes with the sodiums.
Cheers
David
David and Terrie 2006 Winnebago Alpine Not all who wander are lost.
G'day David, been surfing in NSW and playing some music with friends for the last 6 weeks and got home last week. Put another long range tank on the cruiser before xmas, now it carries 330lt and with the upgraded gearbox, was able to do the entire trip without refuelling, the upgraded 5th gear has given the car an extra 300-400klms with very little lose of power in 5th, getting just on 10kpl on the highway. Overtaking is a bit slower than it used to be in 5th, so use 4th gear for overtaking a lot.
Sidecar is at the painting stage, spent time setting it up and tuning it which was a good learning curve as was the realisation it was too light for the VTX 1800, almost tipped it over when testing it without anyone in it. Neighbour pulled the pin after a couple of rides testing, says I'm crazy, which have known for decades. The acceleration is what freaked her out and lifting the chair on corners, it sure accelerates fast and is really stable with the chair on it. Before under hard acceleration, the bike tended to twist a bit and lift the front wheel a bit, now with the chair it just sits on the road and no longer have to battle it, really stable and straight down the road.
Learnt from online research that this sidecar is designed for a bike up to 750cc and weighting less than 600kg, the vtx is a bit over 760kg. So decided to increase the strength of the frame and cut up some old dozer blades which are pretty heavy and after putting them into the chair worked out what was needed to make it more stable and not lift as easy. Took of the body and welded them on the frame, now just waiting for a couple of things so can paint it. The auto paint shop in Hobart gave me two samples of candy red, one a standard and the other the paint bloke made up, along with a cool purple for the flames. Also gave me some silver undercoat which he says will make the red really stand out and paid for a litre of clear coat for the finish, just waiting for a new spray gun and pressure control, then will see which paint fits best with the bike and probably end up re-painting the entire bike. Been experimenting with my airbrush as haven't used it for a long time and will see what can do to make the flames stand out more, just have to do one or two stencils and play round with different colours inside the flames. Knowing my artistic talents, the flames will probably end up just purple. The carpet glue arrived yesterday so can carpet the inside of the chair and the dogs goggles harnesses and crash helmets arrived, so they are in for a surprise very soon. Attached a photo of the current state of the sidecar fitting.
Terry, my 700ah house pack is one year younger than the portable pack and as of yesterday, still holds 100% and have added the 480ah bus pack to the house just before xmas as not using the bus and only realised the rego had run out whilst was away and now it has to be re-registered, or sold unregistered. My neighbour has bought 600ah drop in lifepo4 off ebay, they are really cheap now and you can get 100amp LFP batteries for around $300 with 10 year guarantees.
There's also a number of videos showing a couple of different ways to make sodium batteries, some just using salt water and plastic pipes and they worked. But they don't state what AH they are, just lit up some globes, when get the chance will have a go at making one and seeing how it turns out.
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Switches have issues with the higher DC voltage, they tend to arc across the contacts and either stop working or weld themselves closed so you can't turn them off .... and a few more issues as well
