Greenbatteries.com - Responsible Renewable Energy: 04/15/2007 - Greenbatteries.com - Responsible Renewable Energy - batteries - information on rechargeable batteries and battery chargers

Hi Lewis,

That is my opinion exactly. You sound like a real battery engineer. ;-)

Curtis

Responsible Energy Corporation
Curtis Randolph - CEO
16157 Galena Meadows Drive

Reno, NV 89511

phone 800-790-7866

fax 815-301-3958
cell 775-722-9901
www.greenbatteries.com

From: Lewis
Sent: Friday, April 20, 2007 8:01 AM
To: info@greenbatteries.com
Subject: Swapping NiCd and NiMh batteries in older cordless phones.

Hello,

I am trying to determine if a NiMh battery can be safely substituted in an 8 year old cordless phone which was only certified to support NiCd batteries.

The Energizer website proposes their 1500 mah. model ER-P730 as a substitute for my particular cordless phone model (UNIDEN) which normally takes a 600 mah. NiCd BT-905.

I have examined my phone's cradle and note it provides a charging voltage of 5.8 volts and 85 ma. when charging its NiCd 3.6 volt battery.

I assume that if I swap the 600 mah NiCd for the 1500 mah NiMh, then if the charging current remains the same, then 85 ma. of charging current (0.056C) would constitute the equivalent of a trickle charge and there would be no risk to over-charging the NiMh battery. It may nevertheless take 17 hours to charge up the NiMh battery from empty, but that in itself should not create a fire hazard.

If this makes sense to you, then this would explain why there are some many battery retailers in the world who wholely recommend the use of their NiMh batteries in cordless phones which were only certified for NiCd batteries.

The disenting opinion comes from UNIDEN who may not want to risk having a product liability problem and from experts who know that in fast charge applications, it is dangerous to use a NiMH battery in a NiCD-only charger which does not have the proper technology to detect full charge.

Any comment from you would be appreciated.

Lewis Heilig

Montreal

Hi Richard,

This charger says in the instructions to only charge NiMH batteries. I know from experience that you need to be careful not to charge batteries that are not designed to handle a fast charge rate. Your Sanyo batteries can certainly handle a fast charge rate. I have used the Energizer batteries with the 15 minute charger, Sanyo 2300 and the greenbatteries.com brand too. This charger can get the batteries VERY hot while they charge so if the battery has a fault it is likely to really push it hard. Interestingly it gets the Energizer brand of 2200 mAh batteries the hottest, but that is probably because they are brand new.

The charger also has a very sensitive "bad battery detector" I was just charging four 2300 Sanyo batteries and the Energizer charger did not like one of the Sanyo batteries (if the light blinks red, you have a bad contact or a bad battery and the charger will not charge any of the batteries, not just the one that it thinks is bad. The ten cell charger charged it up fine though, not sure what that means.

Hope that helps.

Sincerely,

Curtis

Responsible Energy Corporation
Curtis Randolph - CEO
16157 Galena Meadows Drive

Reno, NV 89511

phone 800-790-7866

fax 815-301-3958
cell 775-722-9901
www.greenbatteries.com

From: Richard Vassar [mailto:richardvassar@earthlink.net]
Sent: Monday, April 16, 2007 9:17 PM
To: Curtis Randolph
Subject: Re: Greenbatteries.com has Energizer NiMH Products!

Hi Curtis,

Do you know if the Energizer 15 minute charger compatible with the Sanyo 2300 mAh NiMH AA cells that I own?

Best Regards,
Richard