Author Topic: Connecting 2v Lead Crystal Batteries Correctly  (Read 4532 times)

marks

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Connecting 2v Lead Crystal Batteries Correctly
« on: August 25, 2015, 01:48:46 PM »
I have purchased 24 CNFJ-1000 Lead Crystal batteries (See)

http://leadcrystalbatteries.com/media/wysiwyg/Datasheets/2V/Lead_Crystal_Batteries_CNFJ-1000.pdf

to be connected in series to give 48 volts for a 15Kw Microcare inverter. A single battery has 4 neg and 4 pos terminals. The configuration is such that it appears that internally the battery is split into two 500AH batteries. I thus get a 2V reading over the LHS two terminals or over the RHS two terminals. There is no reading over the furthest LHS to the furthest RHS terminal.

As I need 48V the batteries need to be in series. Two options exist to do this and advice or hopefully some technical information could be shared with me. Your help will be appreciated. Regards Mark you can mail me marks@easpe.co.za

Method One: Connect each one of the cells from one battery to the next in series for all 24 batteries and put a "bus bar" over the final row of negative and the final row of positive cells with one lead going to the positive input on the inverter and one to the negative.

Method Two: Connected the two center terminals, negative together and positive together of a single battery and then the two outer terminals negative to positive of the following battery. This would make each battery firstly connected in parallel and then in series.

I have been given many opinions by "experts", but nobody has any technical backing. I quite frankly do not have the ability to decide. Can somebody please help.
« Last Edit: August 26, 2015, 12:30:16 AM by marks »

SeanB

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Re: Connecting 2v Lead Crystal Batteries Correctly
« Reply #1 on: August 25, 2015, 02:28:16 PM »
At a guess you need to bus all 4 terminals positive and negative on each cell, so that the current flow is shared between the terminals equally. Then connect the batteries all in series with jumpers.  The 2 terminals per cell is there likely to keep the current per terminal down,  The max rating of 10kA per battery indicates the terminals are rated only for 5kA each, so the internal bus bars likely are limited to that as well.

Connecting like that also reduces the risk of terminals shorting together.

marks

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Re: Connecting 2v Lead Crystal Batteries Correctly
« Reply #2 on: August 26, 2015, 07:24:10 AM »
Thanks so much for the response. I do not understand why all in series and the last in parallel will not serve the same function. Could you perhaps elaborate.

SeanB

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Re: Connecting 2v Lead Crystal Batteries Correctly
« Reply #3 on: August 26, 2015, 11:46:15 AM »
No real difference, just that there is more risk of you making a mistake in connecting them together. There you have to have a diagonal jumper per cell block, and there is a great risk of incidentally connecting a cell in reverse doing that.  A battery capable of 10kZ will at a minimum cause a blast of acid to vent if it is shorted, and can explode with great violence. Something best watched from afar. As well placing each block in parallel means you can easily take out individual cells to service them, and no jumper wires interfering with the filling holes.

marks

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Re: Connecting 2v Lead Crystal Batteries Correctly
« Reply #4 on: August 26, 2015, 12:13:49 PM »
Dear Sean,
Thanks again for your response. I have already done the connections and am running the system in a series fashion with a bus bar on the ends. The batteries feed into a 15Kw microcare inverter and works perfectly. My question arose because I was told by an installer that I should have connected each battery in parrallel before going in series. He could give no reason. Your practical point of view for maintenance purposes makes a lot sense. Thanks again. Regards Mark

SeanB

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Re: Connecting 2v Lead Crystal Batteries Correctly
« Reply #5 on: August 26, 2015, 02:15:25 PM »
Make sure you use fully insulated tools when working on them, along with not having any metal jewellery ( including rings and a watch strap made from metal or with a metal clasp) on, and only use those tools on the battery and having them stored next to it.

At that power level you will find any accident to be very hot.

marks

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Re: Connecting 2v Lead Crystal Batteries Correctly
« Reply #6 on: August 27, 2015, 07:10:47 AM »
Found a manual see http://leadcrystalbatteries.com/media/wysiwyg/Usermanuals/User-Manual-Lead-Crystal-Batteries-ENG.pdf?

This manual clearly states that the batteries must be put in series and parallel at the end.