MemberMarch 15, 2019 at 2:28 am
Hi Rob and Clive, Thanks for your comments. They are much appreciated.
The batteries I’m working with are from a 5 year old Acorn 120 lift. Genesis NP7-12FR 12volt, 7.0 AH..
In response to Clive’s question: When I removed the top of the sealed battery ( as described in several internet videos), one sees the 6 rubber like removable tops of the six 2+ volt cells which make up the 12+ volt total. Removing the rubber like tops, peering into the top of the cells, some had a liquid covering the plates, and some did not. I assumed the liquid was probably water or weak sulfuric acid. Two additional factors gave me confidence that these batteries had liquid electrolytics: (1) the battery case had a warning indicating sulfuric acid was a component part of the battery, and (2). the 16 page Genesis Application Manual for the NP and NPX batteries ( downloaded from the internet) had these words in a chart ” All GenesisÂ® NP batteries utilize an electrolyte suspension system consisting of a high porosity, glass fiber material which in conjunction with plates, totally absorb and contain the electrolyte. No silica gels or any other contaminants are used.” I concluded from all this that the cells used distilled water. I have to admit however, I don’t have a 100% record of coming to the right conclusion! But the fact that the batteries have reached a bit over the 12 volt level gives me a bit of confidence that I’m on the right track..
In response to Rob: Your comments regarding how lift batteries are tested through 10 journeys in 24 hours was quite informative and helpful for my thinking process. My past experience with lead acid auto batteries gives me doubts also that it is difficult, if not impossible, to restore an older/hard used battery to 100 % of it’s initial ratings. My curiosity and spare time is leading me to experiment with these sealed batteries. I don’t have the lift I purchased installed on stairs yet, otherwise I’d simply measure the battery amps when the lift was running up and down the stairs. I was hoping someone could give me a general idea for what that range might be. I’m going to see if I can get any information on the specifications of the motors used in lifts. That could perhaps give me an idea of an upper limit of current for the motor design horsepower. 0
Two graphs in the Genesis Application Manual for the NP and NPX batteries tweeks my curiosity even more about the capabilities of the batteries used in lifts. . It’s Fig.1 shows battery current discharge vs time, and implies ( to me) the NP7 can discharge 20 amps for a couple of minutes. Fig.3 shows discharge time vs battery terminal voltage as a function of current drain. It also shows the NP7 at a drain rate of 3 CA ( I’m thinking that implies 3×7 or 21 amps) as having a terminal voltage of 11.3 volts for a minute, and dropping to 10 volts at 5.5 minutes. That’s a surprising capability to me.
Whoops, didn’t mean to get so long winded. Thanks again for your comments.
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