Using Protected Cells to make 7.2v ????

[vvenom]

Hi all i know this is here but i have searched and searched with no luck i have purchased some TrustFire Protected 3.7V 2400mAh 18650 but i want to make a 7.4v stick pack
i also have the 7.4V PCB that i know i cant use with these protceted cells :(.

Is there a way of wiring these 2 trustfires up to output 7.4v ?


Im sorry in advance if this is already posted but i need your advice on this please ?

5604

[Jay-Kento]

http://forums.thecustomsabershop.com/showthread.php?12829-Li-Ion-Battery-Packs

this should answer your question.

[Jedi-Loreen]

Yay, a new person that knows how to search. ;)

[Caine Drathul]

Yay, a new person that knows how to search. ;)

Miracles never cease. ;)

Haha, just messing around. But you are not going to have much luck with (2) 3.7V batteries being wired together for a 7.2V stick pack.....but you WILL have A LOT of luck of you are trying to make a 7.4Vpack

[vvenom]

Lol Caine i didn't even notice that :roll:

just trying to find a wiring diagram now so i can test it before i connect it to my pc-u

[vvenom]

Here is a very rough diagram of what i think will be correct after i fully Charge each battery

Can i get some feedback on this before i solder them up :)

Thanks heaps guys

5601

[Wong Yoon Wei]

Uhh guys, he specifically mentioned that he has two protected cells. I thought it's a no no to make a pack out of protected cells because one of the cell might not get a full charge?

[Silver Serpent]

You *can* do it. Charge both batteries to full before you assemble the pack. Eventually you are likely to run into a situation where the battery charges are no longer balanced, and you'll end up with reduced runtime. It will work though, it's just not ideal. It's best to use identical brands and batch/lot batteries if you go this route.

[Rhyen Skytracker]

When making battery packs with protected cells it is best to use batteries from the same batch and measure the voltage before you charge them (to make sure they are the same) and then also measure the voltage of each battery after you charge them. You want them to be as close as possible to have them drain and charge at the same rate. I have some battery packs made this way in sabers that are over 2 years old and they still hold a good charge. However, if you get 2 batteries that drain or charge at different rates the battery pack may not even last 3 months. That is why it is critical to try to match the batteries the best you can.

[vvenom]

Hey all i posted a wiring schematic of what i think i will need to do can i get you to have a look please

Its in the first post

[Crystal Chambers]

Your port is backwards. Positive shares a post and the the negatives each have their own.

http://forums.thecustomsabershop.com/showthread.php?2235-Recharge-port-hookup&highlight=recharge+port
http://www.youtube.com/watch?v=wSp9hRKkYDM

[vvenom]

Thanks heaps for that i totally missed it :)

But other than that im good?

Again thanks for the reply