neptronix said:
flippy said:
I rekon many single payer healthcare countries will not face this problem but in 2nd/3rd world countries like america you are royally frocked if this happens.
I'd like you to refrain from insulting the country most of our users live in like that in the future. Not necessary to go there in a problem solving thread.
considering we are talking about modifying devices people use for medical reasons and the way american healthcare works its a valid point to make.
that you dont like to be confronted with the shitty reality that is the american healthcare system is a personal thing, i am strictly talking about the legal ramifications of these modifications if an insurance company gets involved.
and as you stated: most people are american. so its nothing less then prudent to warn people of considerable risks like their coverage getting denied. something people often tend to forget. same thing happens overseas, if you drive around on a souped up scooter or an unsafe car and something happens the vechicle insurance will utterly destroy your (financial) life.
And no, i dont think american shitty healthcare system is funny, but that does not mean i cant poke a bit at it.
nicobie said:
Even with lead acid batteries those mobility carts are prone to tip-over. If a person wanted they could add a bunch of water jugs to lower the COG when using lithium. This would add pennies to the cost.
lead is litteraly 11 times more dense then water.
Chalo said:
How? I linked to cells which were just a normal 35Ah SLA and the first prismatic LFP I found that looked like it it could pack into a similar shape. I didn't go shopping; I took the first examples that I found with dimensions and weights. The only selection I did was to avoid comparing cylindrical with prismatic for density purposes. Embedded links are still there in the above, unedited post. Have a look and do the calculations yourself, if that makes you trust them more. I was telling you what I already know from working with LiFePO4 packs, which is that they're heavy like other batteries. They contain a lot more juice than SLAs, but if you stuff a compartment full of LiFePO4 prismatics it will weigh close to the same as the compartment full of SLA-- about 3/4 as much according to the first back-of-the-envelope numbers I did. I think your "three or four times" ratio must be comparing volumetric energy density rather than physical density.
your link of lfp batteries is broken so might want to fix that first before ranting on.
but lets grab my numbers: a standard 12V 40Ah SLA battery clocks in around 15 metrics or 30~35 freedom units. a single 40Ah winston cell weighs about 1.5 metrics and you need 4, so 6 metrics. 6 metrics is about 13 freedoms. if i devide 30~35 freedoms by 13 freedoms i get about a third of the weight. and that is with good quality yellow cells, not the crappy purple cells.
SLA volume 5.5L
lifepo volume 3.5L
lifepo is only 40% smaller in volume for the same energy but its a third of the weight. not that great if you need weight. unless you want to pay a LOT more for cyclindrical cells and have shitty lifespan. but then you are better off with a honeycomb of 18650 cells. that does weigh a lot more and stores a LOT more energy.