battery charging issues

**terry** · 3rd July 2011, 22:21

If your stuck, post em to me and I will cycle them 4 u.

**Danjr1** · 3rd July 2011, 22:23

Another weird thing, the 7.2v isnt discharging at all (well 0.02amps) but the 16.8v is discharging at 1.05 amps but the voltage isn't really dropping?

Thanks Terry. I'm thinking of getting a new constellation unless anyone has any suggestions?

**Danjr1** · 4th July 2011, 19:05

ive ordered a new constellation (should arrive tomorrow) and i want to run through the procedure one more time so please feel free to call me stupid if any of this is wrong.

1. to start with i have a 16.8v 4300 nimh pack and a 7.2v 4300 nimh pack. both made up from the same type of cells from the same company.
2. i will be discharging both to 0.8v per cell on the corresponding set-ups (max discharge 3A)
3. I will then charge both up to full capacity (one after the other as i only have one charger, max charge rate 3 amps)
4. I'll then join them up as required to make a 24v 4300 nimh pack
5. This will then be discharged on the NIMH automatic setting
6. The next time its charged will be on the auto setting again (probably will end up cycling a couple of times)

**Danjr1** · 5th July 2011, 17:03

Any help?

**Anttazz** · 5th July 2011, 17:38

Can you not charge it as one pack? I'm not familiar with that charger so cant help on the technical aspect of it, but i'm confused as to why you're doing that.

**Danjr1** · 5th July 2011, 17:42

Before joining them up, I've been informed on the forums that both packs must be fully charged?

**Anttazz** · 5th July 2011, 17:48

Ahh you're going to physically join them up?

I meant charge them in series and just leave them as they are in the robot. Hopefully that takes away a potential problem of having to remake the packs, might also let you cram them into the robot a bit better if space is a bit tight.

**Danjr1** · 5th July 2011, 19:27

oh! they are to be wired in series and installed into the robot, where they will stay unless theres a reason to remove them. Its just i have to charge them before i connect them in series (i think?!)

**Anttazz** · 5th July 2011, 19:36

Ahh ok. I just soldered 2 deans connectors in series and connect that to my charger and charge them through that. Thats 2 9.6v 3300mAh batteries so I tell the charger it is one 19.2v 3300mAh battery and that has always worked for me.