|
|
Rechargeable NiMH BatteriesI and some friends have been using rechargeable NiMH batteries in Digitrax throttles for quite some time. All of our batteries and chargers (except the Radio Shack ones mentioned below) have been purchased from Thomas Distributing (http://www.thomasdistributing.com) -- they have been excellent to deal with, and always seem to have the latest technology on the market. (I have no financial interest in this company except as a satisfied customer.) Batteries
We have used successfully these nominal "9V" batteries:
All of these batteries will charge to 9V or greater, as compared NiCD batteries and some NiMH 9V batteries (like the Radio Shack) which are really 8.4V batteries. For example the Maha & Tysonic will actually test at 9.5V, and Plainview at 10.1V (no load). A few notes:
Chargers 9V NiMH charger technology has substantially lagged the AA/AAA NiMH chargers. Amongst us we have half a dozen Maha NiMH AA/AAA chargers in use
and they are excellent. But until recently no one made really smart NiMH
chargers for 9V batteries. I mentioned the Plainview chargers above. I was interested in
trying the Plainview high end charger, since it keeps a small trickle
charge on the battery, unlike the single battery charger. But could not
justify the expense.
(NiMH are great for high drain apps, but one of their issues is that they lose a significant amount of their charge over a relatively short shelf life (1-2 months), so I like to have some in the charger ready to go when I need them. The AAA/AA chargers like the Maha C204 are excellent in maintaining batteries at their ready. Having a charger like the Plainview single charger is a pain, because if you have several batteries to charge, you need several chargers, and you need to plan their use right before you need them to get the optimal charge at time of use. I always wished Plainview would do a 4-6 battery version of their high end charger. Note Plainview batteries were designed for the cordless microphone market, and thus for commercial A-V use the 10 battery charger and its price aren't really an issue.) Radio Shack makes (?made - perhaps recently discontinued) a NiMH charger (23-422) that is a Fast charger for up to 8 AA/AAA batteries (in pairs) or a slow charger for 1 or 2 9V batteries. We've tried these and they seem to work OK -- I've used it to charge the Maha 9V's I have. A buddy says they even charge his Plainview batteries OK. The nice thing about the Radio Shack 9V charger circuit is that even though it is slow, it has a timer, and shuts off after a given amount of time (9 or 10 hours as I recall), so the battery won't be over-charged. An improvement over the Plainview charger, but it doesn't address the trickle charge issue. A new product on the market recently is the AccuPower AccuManager 20 charger. From a German firm, the product has six independent charging
circuits and will charge up to 4 AA/AAA/C/D batteries (any mix) simultaneously with 1 or 2 9V batteries. And smart technology for the fast
charging/trickle charging that is normally found on the AA/AAA chargers
also exists on the 9V battery charging circuits. I have two of them in use,
but with limited time on them so far. We'll see how they perform over time.
If they perform as advertised they will be a great solution. In fact the
firm claims to sense the particular battery composition/technology in use
and adjusts the charge appropriately. Because they support trickle charging
9V's, I keep them loaded with 4 NiMH batteries. I've been carefully measuring and recording batteries, so hopefully in a few months I can
really tell how they are performing.
Another new charger to the market is the Maha MH-C1090F 9V Multi-Channel Smart Charger. This one has smart charging technology as well, and will charge up to ten 9V batteries simultaneously on independent charging circuits. And it will charge the 9.6V batteries as well. A friend just purchased one, and his experience to date is that it has identified some bad batteries, and reconditioned others -- both items that his other chargers had not done. A few other notes:
|
|
|
|
Copyright © 2002. All rights reserved.
|