Model Boat Mayhem

Please login or register.

Login with username, password and session length.
Pages: [1]   Go Down

Author Topic: Charging batteries  (Read 2637 times)

rwalker

  • Guest
Charging batteries
« on: May 13, 2008, 10:48:26 pm »

Hi all, I'm using those 6v 4amp gell cell batteries for my new project, and while well versed in charging them, I intend hook 2 of them up in series to get 12volts out of them. Do I have to charge them up separately or can I charge them at 12 volts ( I have dual voltage charger) together?

Rev
Logged

chingdevil

  • Guest
Re: Charging batteries
« Reply #1 on: May 13, 2008, 10:57:54 pm »

You will need to charge them up separately, you can not charge gel cell batteries while they are connected together.

Brian
Logged

grasshopper

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 773
  • Location: Lincolnshire!
    • A1 Hobbies Ltd.
Re: Charging batteries
« Reply #2 on: May 13, 2008, 11:49:20 pm »

I think you'll find if the batteries are of the same amp/hr rating and both 6v., you can charge them in series on a 12v charger.
Logged

rwalker

  • Guest
Re: Charging batteries
« Reply #3 on: May 14, 2008, 05:54:18 am »

Ah, conflicting answers which one's right?
Logged

FullLeatherJacket

  • Guest
Re: Charging batteries
« Reply #4 on: May 14, 2008, 07:47:02 am »

Ah, conflicting answers which one's right?
Rev
To be on the safe side you should charge them separately.
FLJ
Logged

Rex Hunt

  • Guest
Re: Charging batteries
« Reply #5 on: May 14, 2008, 07:54:36 am »

Problem is that 2 'identical' batteries (even from the same manufacturers batch) may have different charging/ discharging characteristics.

Also remember that the batteries may not have been discharged to the same level.

If you try to charge multiple batteries, this could result in overcharging one or not fully charging the other.

This I suggest is the reason for the advice above to treat both batteries separately.

 O0

Rex
Logged

funtimefrankie

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 1,259
  • Location: Birkdale, Lancashire. twixt the Mersey & the Ribble
Re: Charging batteries
« Reply #6 on: May 14, 2008, 11:00:35 am »

When  I worked for BT we used to couple the two exchange batteries and charge them together. Then every so often one battery would be given a "gassing" charge.
Mind you these batteries were the size of your house :)
Logged

grantl

  • Guest
Re: Charging batteries
« Reply #7 on: May 14, 2008, 11:47:45 am »

"Problem is that 2 'identical' batteries (even from the same manufacturers batch) may have different charging/ discharging characteristics."

While this is true, surely it's also true that the same could be said for the internal cells of each battery and we don't have a problem charging them in series?

Regards,

Grant.
Logged

grasshopper

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 773
  • Location: Lincolnshire!
    • A1 Hobbies Ltd.
Re: Charging batteries
« Reply #8 on: May 14, 2008, 11:52:13 am »

Quote
I intend hook 2 of them up in series to get 12volts out of them. Do I have to charge them up separately or can I charge them at 12 volts ( I have dual voltage charger) together?

If you have a problem with what i suggested then fully charge each battery seperately using your 6v charger, then from what you've written, in use they will be a 12v battery from then onwards, charge them as a 12v.

I charge my 6v batteries in series using a 12v charger - works for me, had no problems and I use them seperately so the discharge rate is variable.
Logged

victorian

  • Guest
Re: Charging batteries
« Reply #9 on: May 14, 2008, 01:45:40 pm »

I think there's a spot of confusion here about 'series' and 'parallel'.

As grasshopper says, you can charge batteries that are in series 'till the cows come home. By the way, 'series' means that power is supplied from only one terminal on each of the batteries, the outer ends being connected. So, for instance, the red wire on the ESC goes to + on one of the batteries. The - terminal on that battery goes to + on the other battery. The - on that battery goes to the black wire on the esc. Confused?

Never be tempted to connect batteries in parallel ie. + to + and - to -. As has been said already, all batteries exhibit small differences. This why when you connect a jump start battery on your car there is often a small flash as current rushes from the 'good' to the 'bad' battery. You don't want that in a model boat. Worse, if one of the batteries should fail, the resulting current flow will soon turn your pride and joy into a blazing wreck!

Logged
Pages: [1]   Go Up
 

Page created in 0.097 seconds with 21 queries.