"Andy" wrote in message
...
Looking for recommendations for 9 volt NiMh batteries.

EBL has one they claim has a 600 mah capacity.

What about Tenergy's 200 mah battery ?

Been using the Tenergy's NiMH 9V 200mAH batteries and their higher capacity
9V lithium batteries, the former for over a year in smoke detectors and
other devices with no problems. Well made, no bulging like other 9V NiMH's
I have used and sturdy battery snaps. White color with enough room to write
date of acquisition and date of charge on the battery case, too.

They are a far cry from the very crappy 9V rechargeables I've used
(apparently Micky, too) over the years that always oozed greenish goo at the
terminals after a short while and would rarely ever charge back up to full
voltage after just a few uses. I was reluctant to even try them but 9V
alkalines are getting incredibly expensive and I have had very good luck
with their AA, AAA and Roomba batteries.

One important difference is that although the lithium models are much higher
capacity (500mAH if IIRC) they top out at 8.4 volts and that's low enough to
make some devices unhappy - i.e. they'll complain of low voltage.

I was very skeptical at first because of bad experience with even name brand
rechargeable 9V NiMH (including Eveready) but these are holding up well.
Especially nice for smokes and for meters without auto shut-offs and my
advancing senility which means I often forget to turn them off. (-:

Now my smoke detectors can be replaced with freshly charged batteries every
6 months without me ending up taking out batteries that may have a year left
on them just to be sure they'll last. All batteries still had good voltage
after six months and I left one in without recharging to see if it can make
it a year. We'll know soon as the DST change is approaching. That's when I
will replace all the alkalines with either the NiMH or lithium 9V batteries.

Bought two different chargers - a four-banger with separate power supply and
individual LEDs and a two bay model with folding plug and with one LED for
the two batteries (less nice). I did that because I wasn't sure the old
charger was suitable for the lithium units (and still am not sure).

The sheet that came with the two bay models says it's good for lithium and
NiMH 9V so I use the old charger for the 200mAH NiMHs and the 2 bay unit for
the lithiums, just to be safe. Takes about 8 hours to charge the 500mAH
lithiums, so it's clearly a slow charger (which is just fine with me
considering they're lithium cells that can burn very hot if overcharged).

Tenergy alleges full capacity takes several charge cycles. I saw no
increase from the 8.4V on the lithium cells and very little different in
capacity (I used a little snap on LED flasher to drain them and set them up
in front of a CCTV camera so I could precisely time how long they took to
discharge by reviewing the recording.)

If you're interested I'll look up the exact model numbers.

To answer your question succinctly, I am very satisfied having used the NiMH
Tenergy models for over a year. The lithiums are new additions and I've
only had them for a few months, but so far, so good. The 500mAH capacity is
great for things that can benefit from extended run time and I'll bet that
like most lithium cells, they'll hold their charge far longer than the NiMH
cells.

FWIW, I use dozens (maybe hundreds) of Tenergy AA and AAA LSD cells and have
been very happy with their performance. I just got incredibly tired of
leaking alkalines. Never had a Tenergy cell leak and they seem pretty
resistant to complete discharge (although I have to recondition them if they
show up as 0 volts in my LaCrosse charger).

NB that I use the charger in the slow charge mode since that seems to just
about double the overall battery life compared to my Sanyo quick charger
that leaves them almost too hot too touch but charges them in under two
hours. The only thing I use that for now is to restore a 0 volt battery
enough for the LaCrosse to see it and recondition it (about 5 minutes). The
LaCrosse won't do anything to a battery that reads "null." It treats the TD
battery that's been charged for five minutes as FULL but a run test
indicates it's not. However a recharge cycle or two on the LaCrosse brings
it back to life. Not sure what that implies, just noting it for the record.

I have two different MP3 players that take single AA and AAA cells and they
make great battery capacity testers. I set them in the continuous replay
mode and then record the output to Cooledit on an old tablet PC with a
mini-stereo patch cord. I get a visual graph showing exactly how long they
played to the second. Since the MP3 players are really old models, they
have inefficient chips that drain the batteries fairly quickly so the tests
run fairly quickly. Sometimes old is good!

I've found that when AA and AAA LSD cells start showing a charged voltage
higher than 1.35V, they are heading for the great battery box in the sky. I
also mark any battery that has fully discharged with a red Sharpie so that I
don't use it again in anything critical. That's because with other NiMH
batteries like Maha and Powerex, total discharge is the kiss of death. I am
surprised the Tenergy cells recover so nicely from a TD.

No financial interest, just a satisfied customer who buys them from the
Battery Superstore via Amazon. Reasonable and fast shipping, too.

--
Bobby G.