Hi everyone,
Been reading this forum for a few weeks now. It is apparently the best source for EVT Z-20 and R-20 discussion on the web.
I ordered an EVT R-20 in November with the intention to replace my car with it. I wanted a much cheaper, eco-friendly form of transportation to get to work and handle other in-town trips. My boyfriend has a car that we use for out of town trips anyway, so it didn't make sense to keep paying $200+ a month for gas and insurance on an old car that just gets used for short trips anyway.
But... I live in Baton Rouge, Louisiana and cars are not respectful of cyclists on the roads nor I imagine of slow scooters.
I hope that the scooter can go at least 40mph and has a true range of at least 30 miles per full charge. I can live with that. Plus our roads are REALLY flat and my weight is about 130 so I'm hoping that helps. I also figure that if it allows me to live without a car at least 6-12 months then this experiment paid for itself.
But I'm not an engineer, I'm really not that great with math and honestly get a little lost in a lot of what I've been reading here so far.
I also can't really afford to screw up and ruin the batteries when I'm just getting started, so I was hoping for a simple, easy to grasp, preferably low cost must do to prepare and before I start using the scooter list.
Also, I get it that we put a whole lot of faith in a new company (EVT-America) and a new, untested product. It certainly crossed my mind that the whole thing could be a total scam and I was about to spend my entire year's savings. But I at least thought it was important to me to try and purchase something that was a cleaner, more affordable form of transportation.
Thanks in advance for any and all responses!
That states "each cell in the battery" which I'm sure is different than "between" each battery. So it looks to me, with my limited knowledge of this...all learned from you all...that the EVTA folks took this and ran with it to incorrectly state it as "equalization between batteries in a string" rather than the individual cells of a single battery. I mean couldn't the cells within a single battery be basically equal...and yet the battery be under or over charged in comparison to the others in the string? Ok guys...is this a valid point and question?
Gushar
Gus
A battery is defined as two or more cells. Technically, you could consider 5 12v batteries when connected in series as one battery. It also mentions holding the "battery" at 87.6v until the current slowly reduces. So, I don't think this is implying that it will equalize the cells in each 12v battery apart from equalizing the voltage in all of the cells in the entire string.
I mean couldn't the cells within a single battery be basically equal...and yet the battery be under or over charged in comparison to the others in the string? Ok guys...is this a valid point and question?
This is a very valid point and question. I *think* the process of charging lead-acid cells at a constant voltage of 2.4-2.5v until the current tapers off works to equalize a certain number of cells in a series string when done for a certain amount of time. The larger the number of cells in the string, the more time that is required. And the longer the period of time the more gas and heat that is generated in the cells that happen to be at a higher state of charge and the higher the probability of thermal runaway. These limits define a practical limit for the number of cells for AGM sealed lead-acid batteries. I don't know what this limit is, but it appears to be about 6 cells. AGMs do combine hydrogen and oxygen fairly efficiently to generate heat. In this way, the cells that are completely charged can accept overcharge and generate heat without too much outgassing while allowing the other cells to come up in charge to effectively equalize all of the cells in that particular series string. This is just my theory, and I don't know if there are other factors that help keep the cells within one "battery" equal.
Battery equalizers don't actually equalize the cells, but equalize the voltage for a block of cells to other blocks of cells within a larger string which seems to dramatically increase the probability of equalizing all of the cells in a given amount of time without too much overcharging, gassing, and thermal runaway problems. This is just my theory, it's more of a thought experiment, but it seems to explain things.
This has got me interested. I wonder if the EVTA charger doesn't go into float or standby mode, but instead is custom made to remain in CV mode indefinitely. That would mean the voltage would remain at about 73v until the charger is unplugged. Can anyone confirm this with a voltage measurement?
[url=/forum-topic/motorcycles-and-large-scooters/587-my-kz750-electric-motorcycle-project]KZ750 Motorcycle Conversion[/url]
[url=/forum-topic/motorcycles-and-large-scooters/588-fixing-my-chinese-scooter]900 watt scooter[/url]
Pic from http://www.electri
It would have to be a custom charger since soneil doesn't sell a 60v charger. Soneil does have a form on their site to request custom chargers.
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