latecurtis wrote: ↑
May 29, 2018 4:59 pm
Thanks but no thanks. I wish I had that kind of money but even if I did I would need a lifetime warranty for full replacement.
Even then How much would 60 of those things weigh. A lot more than four 10 Ah SLAs I would imagine. Unless there is something I missed.
You are correct that there are trade offs, and I did not expect you to be able to afford them. They were brought up as an "indestructible" battery, since you seem to keep damaging yours, or at least getting less out of them than you would like.
You have missed two things - You can only safely use about 1/2 the capacity of an SLA unless you are satisfied with sub 100 cycles. Peukert's effect would also mean that you're not going to get anywhere near the 10Ah on the label.
The other thing you missed is less relevant. These babies could output in the multi-kilowatt range, and be charged back just as fast. Flooded lead acid would have a very high peak output, but SLAs usually are designed for things like UPSes and golf carts, and have lower discharge rates. Again, trying to push them hard will cause Peukert's effect.
All that aside, the 3Ah cells were never really meant to be put in parallel, they were designed to buffer energy at extreme levels. They can be charged faster than they can be discharged - and they can be discharged really, really fast. That 12V battery can put out 2.1kw. A 48v could put out 8.4kw. a 9ah version could do over 25kw. Even a flooded lead acid couldn't do that.
If you're looking at the 10ah range, it gets a bit harder, because the 10Ah batteries are still power dense, not energy dense, and so are still very expensive. When you get to the 20ish Ah range, that's when you start getting cost effective. I bought 60 of these. They are being held in customs:
Using the same battery for you:
20 x $18 for a 48v battery = $360 + Shipping. I paid $8 per cell shipping to Aus. = $520.
48v x 28Ah = 1344wh. A well designed eBike can get you 20wh per mile, or roughly 67 miles.
It can put out 13kw without damage - That's easily enough to get you well over 60mph on a flat.
Using a 220v, 10A power point, you can charge it from flat in just over half an hour without damage. You could guerilla charge at shopping centres, reducing that electricity bill of yours.
With >25k cycles and 30 year life, excuse the morbidity, it's something you can leave in your will.
But... It's true what they say... The poor pay twice. Unfortunately, the likelihood is that you'll pay $50 here, $100 there for the next few years, getting batteries you're never quite happy with, and eventually spending more than doing it right the first time.
I'm not saying this to put you down. It's just a reality of life.