Building Nimh Packs, Thermistors, and charging.

Batteries, Chargers, and Battery Management Systems.
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Toorbough ULL-Zeveigh   10 MW

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Post by Toorbough ULL-Zeveigh » Dec 17 2007 4:05pm

I also would like to know what people are using for a charger on oddball voltage packs like deardancer3 suggests, like 38.4V nominal/44.8V full charge.
I know Lowell has used regular chargers (HighPower I think) for charging packs that are one or two cells under the 36V or 24V the standard fixed chargers put out so that seems to be OK to do.

Also tsellers, did you also get your D cells from BNE?
(break-n-enter electronics, good name :lol:)
So far I haven't found anything the equivalent of a Batteryspace/Allbattery in Canada that offers the same kind of selection let alone price.
Kick down the barricades Listen what the kids say.
From time to time people change their minds But the Frock is here to stay.
I've seen it all from the bottom to the top Everywhere I go the kids wanna Frock.
Around the world or around the block Everywhere I go the kids wanna Frock.

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tsellers   10 mW

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Joined: Aug 23 2007 1:41pm
Location: Rocky Mountains, Alberta, Canada

Post by tsellers » Dec 17 2007 4:26pm

I used 2 sources for my 2 packs. As I can buy from GP Battery for wholesale, I bought my first set from them. They cost something like $13.00 per cell if I recall correctly. Problem is they had no tabs and I had to pay Battery World $75.00 to build the pack for me and electonically weld them. I supplied all the parts. Trouble is they did a terrible job and the pack didn't work. They used 16 guage wire where they were told to use 10 or 12, they only crimped the connections on the thermocoupler which fell off, and the battery pack did not work, although they say they tested each cell. When I tried to call them and email them suddenly they were'nt interested, I was so ticked in the end I did a chargeback and I would never deal with Battery World again (they also offered to sell me those same GP cells for $25.00 per cell).

Next pack, I buy the Tenergy Cells for $6.00 each from All_Battery off eBay. They are tabbed, so I build my own pack. ALthough each cell tests out for the correct voltage, it does the same thing as the other pack, gives the hub motor a bit of a forward jerk, and that's it. If I have my multimeter on the charge circuit side measuring the voltage while all this is happening, it does not drop very much.

I just got the electrical components from B&E. They are also expensive, and definetly not what you would call friendly. I seem to get the same guy when I go there who makes if very clear with his body language and attitude that very question is a stupid question, especially asking for the thermister which they don't have. So there you have it, Battery World is initially very friendly but incompetent, B&E is competent, expensive and not very helpful, and All-Battery is fine, inexpensive. I also got some chargers and a bunch of other non-related stuff from them, and most of it was pretty cheap looking, but the reviews I read said that the Tenergy cells are generally pretty decent.
Regards, John

deardancer3   10 kW

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Post by deardancer3 » Dec 17 2007 11:59pm

I guess one of my questions restated is

"will the standared hipower/nexcell 24v charger still work correctlyif i add one 1.2v identical cell to the original pack and try to charge it with a 24v NIMH charger?"

dick

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tsellers   10 mW

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Location: Rocky Mountains, Alberta, Canada

Post by tsellers » Dec 18 2007 12:59am

Probably not.
Regards, John

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