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Author Topic: NiMH Battery Question  (Read 1334 times)

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Offline FlumerTopic starter

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NiMH Battery Question
« on: April 19, 2012, 03:01:05 PM »
I recently bought this battery.

http://www.onlybatterypacks.com/showitem.asp?ItemID=10409.7

However, when I checked out I chose to "Solder tab-solder your own connector".

I bought these servos.

http://www.servocity.com/html/hs-311_standard.html

So my question is, what connector do I buy? And how do I solder a connector to the battery?


P.S. I'm following the $50 robot tutorial.

Offline Soeren

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Re: NiMH Battery Question
« Reply #1 on: April 19, 2012, 08:01:11 PM »
Hi,

So my question is, what connector do I buy? And how do I solder a connector to the battery?
You can use almost any connector that will handle say 2A and up. If you plan to remove the battery for charging, get one female connector for the battery, one male connector for the board and an extra male connector for the charger.
Take a look at some of the connectors used in R/C cars/planes/boats - they are made for high currents and made so they cannot be connected with reverse polarity (once installed the right way 'round).


You solder a female connector to a short length of (2-conductor) wire and solder the other end of the wires to the battery tabs like you solder anything else, but a 15W iron may be a bit too small. Go for at least 35W (50W is even better) and make the connections in the shortest possible time to avoid overheating the battery, but not too short either, as you want the solder to flow well for a good connection.

You can use a short length of mains wire for this.

Be very careful when you work with the battery. Shorting it can start a fire, burn your pinkies and ruin the battery.
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

Offline FlumerTopic starter

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Offline FlumerTopic starter

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Re: NiMH Battery Question
« Reply #3 on: April 22, 2012, 12:13:20 PM »
Anyone? Isn't this place supposed to help people?

Offline joe61

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Re: NiMH Battery Question
« Reply #4 on: April 22, 2012, 03:43:48 PM »
Anyone? Isn't this place supposed to help people?

This place frequently does help people. Sometimes, though, people aren't interested in vague questions, maybe they don't know the answer, or maybe it's the weekend and they have things to do, so they're simply not reading forum right now.

You might try emailing the battery place where you're thinking of shopping. It's their business after all, so they probably have someone there who will know the answer.

Joe

Offline jkerns

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Re: NiMH Battery Question
« Reply #5 on: April 23, 2012, 09:37:13 AM »
http://www.onlybatterypacks.com/showitem.asp?ItemID=11896.63

http://www.onlybatterypacks.com/showitem.asp?ItemID=11897.63

Would these work for example then?


Sure, why not.

5 amp capability should be plenty for the $50 robot.

Sometimes it takes a while because many of us have other things going on - for example - I was sinking fence posts all evening yesterday and was too tired to check on forums when I was done.
I get paid to play with robots - can't beat that with a stick.

http://www.ltu.edu/engineering/mechanical/bachelor-science-robotics-engineering.asp

Offline FlumerTopic starter

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Re: NiMH Battery Question
« Reply #6 on: April 23, 2012, 12:53:30 PM »
Alright, well now I have a new question. I want to get this charger to charge my 1600mA NiMH battery.

http://www.onlybatterypacks.com/showitem.asp?ItemID=10031

What connector do I get attached to it so it is compatible with these connectors?

http://www.onlybatterypacks.com/showitem.asp?ItemID=11896.63

http://www.onlybatterypacks.com/showitem.asp?ItemID=11897.63

I'm not familiar with these things. Trying to learn. Thanks!

Offline jkerns

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Re: NiMH Battery Question
« Reply #7 on: April 23, 2012, 05:49:39 PM »
Well, if you put the female connector on your battery, you need  two male connectors - one for your robot and one on the charger. Or you can do it the other way around. Right?

Make sure you don't  mix up your pluses and minuses...
I get paid to play with robots - can't beat that with a stick.

http://www.ltu.edu/engineering/mechanical/bachelor-science-robotics-engineering.asp

Offline Soeren

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Re: NiMH Battery Question
« Reply #8 on: April 24, 2012, 08:57:12 PM »
http://www.onlybatterypacks.com/showitem.asp?ItemID=11896.63

http://www.onlybatterypacks.com/showitem.asp?ItemID=11897.63

Would these work for example then?

I wouldn't trust them with 5A, even if the label says so - nothing on contact resistance and voltage drop - They're nothing but servo connectors, with 22 AWG wire attached and you should use at least 18 AWG (~1mm in diameter) for the load - charging, especially with only 100mA is not that critical though. I'd go for some polarized power connectors.
Like http://www.onlybatterypacks.com/showitem.asp?ItemID=10066.14 and http://www.onlybatterypacks.com/showitem.asp?ItemID=10067.14
(They're cheaper than the puny servo connectors as well)

Current capability aside, using servo connectors on a battery is asking for trouble.
And so is being too impatient about getting answers - don't ever demand more than what you pay for! Or to put it another way... Paying me $200/hour you'll get the same swift response as my paying customers - until then, you don't really take priority, neither over them, nor over quality time with my family.
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

Offline FlumerTopic starter

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Re: NiMH Battery Question
« Reply #9 on: April 26, 2012, 02:32:59 PM »
http://www.onlybatterypacks.com/showitem.asp?ItemID=11896.63

http://www.onlybatterypacks.com/showitem.asp?ItemID=11897.63

Would these work for example then?

I wouldn't trust them with 5A, even if the label says so - nothing on contact resistance and voltage drop - They're nothing but servo connectors, with 22 AWG wire attached and you should use at least 18 AWG (~1mm in diameter) for the load - charging, especially with only 100mA is not that critical though. I'd go for some polarized power connectors.
Like http://www.onlybatterypacks.com/showitem.asp?ItemID=10066.14 and http://www.onlybatterypacks.com/showitem.asp?ItemID=10067.14
(They're cheaper than the puny servo connectors as well)

Current capability aside, using servo connectors on a battery is asking for trouble.
And so is being too impatient about getting answers - don't ever demand more than what you pay for! Or to put it another way... Paying me $200/hour you'll get the same swift response as my paying customers - until then, you don't really take priority, neither over them, nor over quality time with my family.


I apologize for my impatience. It is finals week and I have been quite stressed out. I believe I have figure everything out.

I ask that you please be patient with me, I am very interested in this field, but have very little understanding of electronics.

My next question is how to solder the connectors I purchased to the battery? My battery has 2 tabs, one is a positive side, and one is a negative side. Does one male connector and one female connector go on each side? Do I split a female connector (red and black) and solder one wire per side? I am quite confused.

Thanks everyone.

Offline Soeren

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Re: NiMH Battery Question
« Reply #10 on: April 27, 2012, 12:18:51 AM »
Hi,

My next question is how to solder the connectors I purchased to the battery? My battery has 2 tabs, one is a positive side, and one is a negative side. Does one male connector and one female connector go on each side? Do I split a female connector (red and black) and solder one wire per side? I am quite confused.

OK, let's back up a bit...
The page:
http://www.onlybatterypacks.com/items.asp?db=63
has got connectors with a length of wire connected. Each is tagged with "Battery" or "Charger" and you need one "Battery" and two "Charger" (as this is the one to use on the robot as well).

One female 2-pole connector goes on the battery - it has got a red wire and a black wire. Red goes to the "hot" positive side/terminal and black goes to the "cold" negative side/terminal.

If you have got the loose connectors already, look at the page to see which is positive. It doesn't matter as long as you never connect up with something else, but following the standards is a good idea anyway.

If you find any of the above unclear, tell us what you've got so far and we take it from there :)
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

Offline FlumerTopic starter

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Re: NiMH Battery Question
« Reply #11 on: May 03, 2012, 10:09:56 PM »
Alright, well I've made SOME progress. My current issue is attaching the battery to the circuit board. My connector for the battery is not the simple 3-hole one in the tutorial...so....what do I do?

Thanks.

 


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