Warning about Topland NiMH gumsticks

[Strungup]

I went to Akihabara , and bought 10 at 800 yen a pop I am out 80 bucks

well not "OUT " but , they Must be trickle charged or Cell imbalance will happen , the SONY NiMH charger is way to fast , charging right at 1C , and the Batteries get hot and shut down . I have a Panasonic that charges at .5C and pulses the charge (instead of steady stream) and it seems to be working .

These will not charge IN the MD Units themselves properly , so a separate charger must be used . AT 500 ma 1.2 volts or even less , slow charging with Pulse , then the cells will not be imbalanced .

Topland 1400ma prismatic NiNH Blue and Orange case .

I have checked the net for specs on other chargers and it seems I am right , the "Prismatics" are set at 700 ma's or less charge rate

here is one in the UK

http://www.smallbattery.company.org.uk/sbc_rc103251.htm

http://www.smallbattery.company.org.uk/sbc_rb103244.htm

It appears they have the Battery for Older Kenwoods and Sharps as well , very cool

http://www.smallbattery.company.org.uk/sbc...03247.htm#equiv

these are the thicker stick lithiums that were in the DMC-G7r and others ( I need a few of these)

Edited December 8, 2008 by Guitarfxr

[scratman]

Maybe this information might help

http://www.powerstream.com/NiMH.htm

[sector001]

can u return then for a refund?

[Strungup]

@scratman , thx for the link , good info , and correct info , I am aware of how to charge batteries ( I Lived off of Solar exclusively for years)

but for the people who buy MD's from me , and arent inclined to "Build stuff" this isnt so good , I bought these to go into my "Garage Sale" items , because I wanted to give those who bought from me a Brand New , battery ( some of these MD Players/Recorders are quite old, as are their batteries as well)

but that page is bookmarked , and I have a bunch of the wall type NiMH chargers (Sony's and Pana's ) I think I will take one apart and make a Slow Solar charger out of it

a few small 1.5 volt 400 ma solar panels , and bingo Gumsticks in the Sun .

@sector , I will call the guy I bought them from , what I did notice , is that there was a separate charger from this company for these batteries. But , I used Sony wall chargers , charged inside the MD , used a Panasonic charger , I tried 6 different chargers with the same results .

on Brand new Batteries .................. not good

[Strungup]

Update : I have one working ....... It had to sit over night , after charging . I have it in the MZ-E33 Blue that is on the Garage sale post playing Pink Floyd ( at 6 am in the morning ........ ) The charging , may have to be done with their own brand of charger . I will look into that , but that is still troublesome for Md'ers if you cannot charge them in the unit .

I just put one in the MZ-E800 and am charging it now , I will let it sit for a few hours , and see what happens . ( This is an unused one , opened a new package )

I think If you do buy these you should get a few , in case of hit and miss syndrome

update

charge light went out in only 5 minutes , which isnt good , that means that as soon as these get warm they shut down , which means that the charger for them would have to be a Trickle Charge temp controlled ,Pulse width modulation type . Which is the same as a Good Solar charger .

The Panasonic charger output is 1.2 volts @ 700 ma's , The Sony Charger is 1.2 volts @ 1.2 amps the MD itself I am not sure of .

Guess I have to go back to Akiba and get one of their chargers , and take it apart .

The MZ-E33 Battery life is this

Battery Life Play

NH-14WM Gumpack 7 hr

NH-9WM Gumpack 6.5 hr

NH-MDAA (AA form factor) 8 hr 3 hr(Charge)

Alkaline AA x 1 9.5 hr

So far I am on the second disc now , Derek Trucks , at the second song the battery marker is down the half of 1 mark , a very thin line , and soon to drop off .

.......... The Topland GMD 1400 , is rated 1300 ma's ........ not dissimilar to the Sony 1400 (1350 ma's ) so I should see at least 4 discs , full play , but I am only on the second , and the battery will die before this disc is thru .

Charging in the MD will not work , Sony chargers will not work , Panasonic Maybe .... ( 700 ma's is less than 1C charge rate , but still ) I think the charger for these has to be a trickle type PWM , I am absolutely certain of it .

Update

Ok an interesting thing just happened , You tell me .......

Made it thru disc 2 , with just a Sliver ( I mean thin thin thin ) battery mark . Then it sat for 3 minutes while I got coffee , and looked for another disc , ......

In Goes new disc , *** ( I am TRYING to run it all the way down here)

Kazu Matsui's :"Sign of the Snow Crane "

Hit play ,........... and the Battery mark GAINED 1 and 1/2 notches , and is showing 1/4 full on the battery mark ??????? I could easily understand a Little gain (Voltage flux) but to go from empty to 25% ???????

Disc 3 Playing now

Update

Disc 4 , Jim Walker , Flight of the Dove , all the way thru , but now back down to a Sliver of Battery mark .

Disc 5 is in ( a Jazz compilation) and just a sliver at the start of the disc .

These things confirm my suspicion , a Fast charger will imbalance the cells in these batteries , then they have to sit and equalize , so a Trickle or slow type charge is what these batteries need

More net searching netted me , this ...... Standard charge 137 ma's , quick charge 200 ma's , There it is folks , Trickle only .......... gotta get a charger ,

OK so I didnt waste 80 bucks , I just have to build or get the right charger , and all is good .

Yet another update ( 6 hours later)

I left and went to check my bank balances , and look at what Blanks were still available at Best Denki , came back , and hit play on the MZ-E33 again ( same battery ) and have a 1/4 mark on the display , so .......hmmm 6 discs , which is full rating on the E33 , ........... Ok I might have been hasty in harshly judging these ( I am unfamiliar with the Prismatic type of NiMH )

and unlike the Sony's these will not charge well on a Rapid charge , but they do take a full charge , and they do Last , 6 discs in an MZ-E33 is pretty good .

So I will revise my statement at the Garage Sale .

Edited December 12, 2008 by Guitarfxr