Batteries get more amazing all the time!

[Beachcomber]

I was in Kmart today looking for some rechargeable batteries and saw a new Rayovac rechargeable NIMH "AA" battery that advertised 15 minute recharging!!!! As if this were not enough these "AA" batteries have a 2000mah rating. Needless to say I was a bit surprised as recharging a 2000mah NIMH battery in 15 minutes seemed a bit much if you know what I mean. You know the old saying if it sounds to good to be true it probably is. Well guess what. It's all true. I just went to Rayovac's website and there is a big writeup about these new batteries and one of the awards they ahve won. Here's a link. I will be using these in my next detector project...actually I will probably use them in my HH PI

HH

Beachcomber



Rayovac 15 Minute Charging AA NIMH

[Chris]

Re: Batteries get more amazing all the time!

Hi Beachcomber

If you buy this rechargeable Rayovac batteries don't forget to buy the charger too. I red the ads on their web page. You need the special battery charger as well! The Charger has a build in electronic to detect the fast charging batteries. With a normal charger you have no advantages.

Chris

[Beachcomber]

Re: Batteries get more amazing all the time!

I know I read that too. I'll take the charger apart and see how it determines the battery type and then make a charger that can charge 8 batteries at once rather than just 4. According to thier fact sheet the charger is much simpler than previous NIMH chargers since the battery handles charge control instead of the charger. At Kmart they were the charger along with 4 batteries for $29.95 so the charger can't be all that special. They were also selling 4 packs of the batteries separately but I don't remember the price of the individual batteries. I was in a hurry at the time and didn't spend a lot of time checking them out. I did that later on the website

HH

Beachcomber

[Gary]

Re: Batteries get more amazing all the time!

Most Nicads and NiMh batteries can be charged VERY Quickly (As short as 10 Minutes) if you Carefully monitor the Delta-V of the battery.

This is the Peak Charge Voltage Attained, Just as it starts to reverse and go lower again. As it than goes lower the current no longer charges the battery, but instead turns into heat, Distroying the battery. This Delta-V is not a Specific voltage level as it varies with the type and condition of the battery being charged.

There are Many Write-ups and Speciality IC's for accomplishing this Delta-V process.

Monitoring the battery Temperature will also work on fast charges, but to a Lesser Extent. Its the Internal temperature that is most critical, not the external temperature.

Take care......Gary

[Beachcomber]

Re: Batteries get more amazing all the time!

I guess that is why they put the charge rate monitoring inside these new batteries. I was at Walmart today and they have an Everady 30 minute fast charge NIMH. I didn't read the capacity of their AA's. I was impressed that the Rayovac's were 2000mah. That's quite a bit higher than the NIMH packs that come with today's detectors. The Minelab Explorer II's NIMH pack is only 1600mah but they will sell you an optional 1800mah. As far as I am concerned the 1800mah pack is the one that should have come with the detector and not as an additional cost option!!! Sorry about that I get annoyed with things like that!!!! Especially on such a high priced detector. It should have been top drawer from the start!!! You shouldn't have to pay extra to get what should have been standard equipment!!! JMHO

HH

Beachcomber

[Carl]

Re: Batteries get more amazing all the time!

I had been using Ray-o-vac Renewals (rechargeable alkaline) for a while, they're great if you keep using them, and don't let em sit around.

More recently, I just buy big bricks of Ray-o-vac alkalines on sale, knowing that they're not as good as most other brands, but heaping gobs cheaper. Sounds like the new NiMH is a big winner, I'll definitely get some for the digital camera, and the PI. Thanks!

- Carl