Need advice on batteries

shmagoogin77 · Post by **shmagoogin77** » Fri Jun 03, 2005 8:57 pm

and if you did it in series you ould have 2000 MaH (say) and 7.2 v

i get it
i get it

also would a battery holder be sereis right?

soundwave · Post by **soundwave** » Fri Jun 03, 2005 9:00 pm

jjcastagna · Post by **jjcastagna** » Tue Jun 07, 2005 4:22 pm

Ok, I think I found what I need. What do you guys think of <a href="http://www.batteryspace.com/index.asp?P ... &ProdID=51" target="new">this</a>? Looks pretty good, with two battery packs and a charger, 7.2V 3300mah.
Does anyone know how to make a "smart" battery charger, though? Like if I wanted to be able to play while charging the battery but not have to worry about over-charging the battery -- just have the charging stop when the battery is full. Does anyone have a circuit for that?

Turbo Tax 1.0 · Post by **Turbo Tax 1.0** » Tue Jun 07, 2005 5:12 pm

batteries look fine but i dont think you need two

nos_slived · Post by **nos_slived** » Tue Jun 07, 2005 5:52 pm

That link is for 2 packs plus a charger, so even though you don't need 2, you would have an extra for backup.

As for a "smart charger", you could use a MAX712 circuit in your portable.

jjcastagna · Post by **jjcastagna** » Tue Jun 07, 2005 8:19 pm

How would I go about getting a MAX712 circuit?

nos_slived · Post by **nos_slived** » Tue Jun 07, 2005 8:55 pm

Get a MAX712 and build the circuit.

If somebody would be kind enough to read my RRW thread in the Trading Post, I would make a Ni-MH charger with a 712, but because nobody has offered, I can't.

jjcastagna · Post by **jjcastagna** » Thu Jun 09, 2005 1:21 am

But does that circuit let you charge and use the battery at the same time? If it does would you make me one to charge <a href="http://www.batteryspace.com/index.asp?P ... &ProdID=51" target="new">this</a> if I got you some free samples?

nos_slived · Post by **nos_slived** » Thu Jun 09, 2005 1:45 am

All you would need is the charger board, some transistors, and a switch. I am working on a layout for it now. I also orderred some samples this morning, but I'm not sure when they're coming.

jjcastagna · Post by **jjcastagna** » Thu Jun 09, 2005 6:04 pm

Hmmm, I still like <a href="http://www.batteryspace.com/index.asp?P ... rodID=1199" target="new">this guy</a>. Would that be ok with <a href="http://www.batteryspace.com/index.asp?P ... rodID=1121" target="new">this charger</a>?

One other thing... is it ok to charge those li-ion batteries and use them at the same time? With these items, can I build the circuit so that I can play and charge at the same time?

nos_slived · Post by **nos_slived** » Thu Jun 09, 2005 6:27 pm

Those batteries would work with that charger.

jjcastagna · Post by **jjcastagna** » Thu Jun 09, 2005 7:20 pm

An idea... If I place two of those Li-Ion in parrallel to get 4.8Ah (as they state on their website), am I risking to damage anything by charging both battery packs at the same time?

Also, how would I connect the battery packs, the circuit and the charger to be able to charge and play at the same time?

nos_slived · Post by **nos_slived** » Thu Jun 09, 2005 7:57 pm

You might not want to use that charger, because the battery's page specifically calls for another charger.

jjcastagna · Post by **jjcastagna** » Thu Jun 09, 2005 8:08 pm

Actually, they also suggest the charger I was looking at, at the bottom of the page...

So if I'm making a circuit that can charge and play at the same time, do I just wire both batteries and the power input from the charger in parallel?

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