Model Boat Mayhem

Technical, Techniques, Hints, and Tips => Batteries & Chargers => Topic started by: MichaelK on August 25, 2010, 10:46:31 am

Title: 7.2v to 6.0v
Post by: MichaelK on August 25, 2010, 10:46:31 am
Hi
 I have a 7.2v 5000mAh pack that has a Dickky cell, so that it only sits at 6.?v  >>:-(
 (I replaced it with another identical pack from HK for 1/2 the price I paid originally) :-)
My intention is to pull it apart, find, and get rid of  the Dickky cell, and re-build it into a 6.0v pack.
The battery charger that I use is a "ANSMAN acs 67p" (delta charge) (whatever that is!)
My Questions are:
 Will my charger blow the battery pack apart?
 Will my charger blow itself up, and burn down the house?
I need another pack to power a water pump to cool the motors.
Thank you
Mick
Title: Re: 7.2v to 6.0v
Post by: DickyD on August 25, 2010, 10:54:38 am
Your Ansmann ACS 67P Quick Charger is only for NiCd/NiMH RC battery packs with 6-7 cells (7.2-8.4V) not 6.0v.
Title: Re: 7.2v to 6.0v
Post by: MichaelK on August 25, 2010, 11:47:44 am
Thank you,
any suggestins?
Mick
Title: Re: 7.2v to 6.0v
Post by: DickyD on August 25, 2010, 12:30:34 pm
One of these ?

http://www.component-shop.co.uk/html/body_radio_control1.html

Click on picture of charger for details of it.
Title: Re: 7.2v to 6.0v
Post by: john s 2 on September 09, 2010, 07:33:02 pm
If youre taking the pack apart.Why not replace duff cell with simelar one.Then you can charge as before.
Title: Re: 7.2v to 6.0v
Post by: MichaelK on September 10, 2010, 12:12:41 am
I hav'nt been able to find single cells the same. :((
I bought a new pack from Hong Kong, but they don't do single cells
Mick
Title: Re: 7.2v to 6.0v
Post by: malcolmfrary on September 10, 2010, 12:19:44 am
If youre taking the pack apart.Why not replace duff cell with simelar one.Then you can charge as before.
Similar isn't good enough, it needs to be identical, or else it will either hog the charge and overcharge or under charge and over-discharge, resulting in early failure of itself or its new mates.  I've had acceptable results using reduced packs for lesser jobs, and rebuilding the remains of two dud packs into one fairly good one, but I wouldn't buy a new cell to fit into an existing pack.  Apart from anything else, the manufacturers keep "improving" things, so a close enough match becomes a problem when buying off the shelf.
Reply just bounced it while I was pecking at the box, illustrating the problem.
Title: Re: 7.2v to 6.0v
Post by: Rex Hunt on September 10, 2010, 08:38:49 am
Surely if theV  and mAH matches there should be compatability?

Rex
Title: Re: 7.2v to 6.0v
Post by: malcolmfrary on September 10, 2010, 11:48:19 am
Surely if theV  and mAH matches there should be compatability?

Rex
Should is the operative word.  Actually finding one of the same capacity and charging/discharging characteristics to get optimum performance is not easy, so, like I said, it is not going to be reasonable to expect the remade pack to have the full performance of the new one.  Depending on the intended use, this might not matter.