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Looking for a NIMH expert.

Looking for a NIMH expert.

Old 10-17-2013, 09:05 AM
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Originally Posted by racer1812
That's a good bit of info! I never knew that dead shorting a pack without a tray could lead to cell reversal.. I don't want to do that to these cells. Im thinking that my course of action here will be to drop their voltages down to .90v and then charge through five or so cycles. I better start looking for an advanced used nimh charger like a muchmore or lrp... Also, I started taking apart the battery pack last night. Honda did quite a superb job with building these to be safe. They even included a circuit breaker switch right on the pack itself to make sure nothing bad happens. I will upload some pics when I get around to it.
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Old 10-17-2013, 09:19 AM
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Show us some pics of what exactly it is that you're working on.
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Old 10-17-2013, 10:24 AM
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Here are some pictures before I began to carefully take it apart;

Inside you will notice orange and green "tubes". Those are actual cells in groups of six shrink wrapped together. There appear to be 22 "tubes" all together.


From the top, this is considered to be one cell from a Honda Hybrid.


This is the business end. It is where all the magic happens. Very neat and I can tell that there was quite a bit of thought that went into designing these cells. There is also a current sensor on the negative lead. Everything looks much much neater then right now, I did take some stuff off and some wires are loose.


This little gem is there to remind me that I will indeed be "Killed or hurt".. Wish me luck guys


Im off to the hardware store to pickup a long socket. Each length of cells is connected to the main frame by a bolt deep inside the business end. Hopefully that is all I will require.. That and a first aid kit..

I will update more soon. I may also pickup a new camera to get better pictures.
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Old 10-17-2013, 01:55 PM
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Here are a few more pictures. The first one is looking at the bottom of the battery pack seeing all the cells aligned.



After taking off the top "business end", im met with the plate which holds voltage sensors for each bank of cells. This plate is also the plate which ties them all together.


After taking that plate off, this is the top of the batteries.
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Old 10-17-2013, 02:12 PM
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I measured the voltages between what I believe to be two banks of cells in series so 12 cells total and the average voltage im getting is from 6.68 to 6.92 volts.. 6.68/12=0.55 volts per cell approximately.. I'm assuming that at that voltage, those cells are all dead?
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Old 10-21-2013, 11:49 AM
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So back to topic, can anyone recommend a good charger designed for NIMH? I know that there are many that will do NIMH/NICD but im curious if there is anything out there that was designed for nimh. I did order two TC-1030's and one orion clubman. The clubman can do up to 12 nimh cells which is good. That will allow me to do one whole "bar" as its manufactured. I expect much longer charge times but that's also expected.
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Old 10-21-2013, 03:14 PM
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One possible issue with a slow charge is the delta peak detection may not work correctly. Too slow of a charge at some point becomes a trickle charge that won’t peak enough to shut off the charger. Any info or idea on the cell capacity? Might need to go to a higher current charger for an automatic peak charge, or use a timer and go by capacity with a trickle charge.
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Old 10-21-2013, 06:56 PM
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Im planning on charging 12 batteries in series at a time at 5 amps. They are built in sticks of six cells but then two sticks are welded together at one end. I was thinking about charging them six at a time by using an alligator glip on the end that is welded together but I decided that if I can find a charger that will handle 12 cells, that would be more efficient. If I find one that is acting up, I will then revert to charging six cells at a time. I don't have a clue what the capacity is of the cells individually or as a "stick". I guess I will find out the approximate number once I attempt to charge a few sticks.
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Old 10-24-2013, 01:14 PM
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I have a question; I want to start charging the cells. I don't know however the Mah of the cells. The charger however is asking for me to input the cell Mah. Is this a suggested number or will the charger continue charging until it reaches this number? I have a charger that I charge my AA's in and it does not ask for the Mah. Instead, it just tells me how many Mah the cells took in. This is realistically what I want. Should I just enter the max allowed Mah that the charger will go to? Im using a TC-1030 charger..
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Old 10-24-2013, 04:46 PM
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Going by the poor cousin ICE charger there is likely a Max Charge Capacity setting (max chg cap or similar), that combined with the capacity setting will limit a charge. I’d go with the max setting to start, guessing those cells are significantly bigger than typical RC stuff? Measure a cell diameter & length, might be able to find info with a little googling, or perhaps Honda forums, etc?
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Old 10-24-2013, 04:49 PM
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I basically set it to the max which I think is 9900mah and let it run. I didn't notice what it got to but it finished charging on its own I think around 7xxxmah.. Ive been monitoring the battery temp's and they peak out around 102f. I'm discharging them now and running a total of three cycles.

I have three of these TC-1030 chargers but im planning on getting two more. Here is the shot of the charging setup currently;


Last edited by M3Roc; 10-24-2013 at 05:06 PM.
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Old 10-27-2013, 06:59 PM
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I'm no nimh expert,but here's some tips I collected last year and personal testing.
Slow charge like .5Amp or 1Amp initially,what you are looking for is to level the charge those cells in sticks get. Some will receive too much charge,that's why a low amp charge is needed,they don't like overcharge. Go by temperature,feel each cell,some may be warmer then others or get warmer soon than others. Too hot and you should terminate the charge and let them rest and lower the charge amp until all are homogeneously warm. On the first discharge do a 1-2 amp discharge until 1.0v,if your charger does a discharge graph you are looking at a "knee" where the voltage drops fast,stop it right there. Let them rest to almost cold and hit them with another around 1amp charge and another low amp discharge until all the cells. Do this again and again until all cells arrive at same temperature at around same time. Record numbers and compare to previous cycle. You'll want "same" numbers for all sticks,discharge amps being more important than average voltage.
Good luck and be patient.
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Old 10-27-2013, 07:40 PM
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These cells seem like very high end cells. Even though they were practically dead, they are charging like champs at 3amps and discharging at 5amps. All of the cells are peaking right at 6100mah +/- a few hunder or less. The cells get to around 105 degrees F when reaching peak charge. Each cell "pack" has a resistance reading anywhere from 26 to 28mΩ. Haven't had a single issue yet, im actually surprised how well they are charging. Here is a pic or the cell's charging currently;

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Old 10-28-2013, 03:22 AM
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Now I see,your charger is very similar to mine. Mine is a Robitronic Overloader,the menus are the same but mine has the charge/discharge graph capabilities.
Seems to be going well,and about discharge numbers? Average voltage and mAh?
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