maha 777 plus 2

[Brock]

Ok, I just got my maha 777 plus 2. So I thought I would start yet another thread about it. I got it on ebay for $80.

My favorite feature is the mA in during charge. I use NiMH batteries all around the house and I had been just charging them every week not know how much was really used. For example I have a baby monitor hooked up to 4 9000mA D cells. I just charge them once a week no matter what. I know it draws about 25mA and runs 24/7 so in a week it should use about 4000 mA. Well now I am going to find out. I also have a couple of LED night lights that run on 4AA cells, again I can guess how much power they are using over the week, but now I will finally know how far I am discharging them.

I am sure I will find more things to like or are odd as time goes on.

What other thing do people like / dislike about it, any tricks I should know?

 

[PaulW]

Brock,

I got mine only last week. I really have nothing to compare it to. It's my first store-bought charger. I have no complaints at all. It's easy to use and does the job.

I tried it on a protected Li-Ion cell, and it worked flawlessly. However, the battery started to make a whistling sound -- around 5KHz to 10KHz. The sound would go away when I moved the battery. I think it was the battery and not the charger.

I had no holder for the Li-Ion cell so I wedged it in a slit piece of radiator hose. I slipped in a piece of metal to contact the positive terminal and a spring for the negative. A strip of duct tape held the whole thing together. I guess you could call that a trick.

I, too, would like to hear about other people's tricks.

Paul

 

[Brock]

I know the LiIon charges at a lower rate, but are the stop points differnt? I gues what would it do if you set it to Li and charged Ni in it? It shut off charging a 6AA pack, it got to warm. So I was thinking of trying the same pack on Li, but for some reason I think that might not be a good idea.

 

[koala]

PaulW,
I don't know what type of Li-Ion cell you use but have a look at LitFuse style cool... /ubbthreads/images/graemlins/buttrock.gif

Vince.

 

[PaulW]

Brock -- I also have thought about using the Li setting for NiMH batteries. But note that the 777+2 looks at voltages in multiples of 3.6, not 1.2, on the Li setting. So I would guess it would work only for 3, 6, 9, or 12 cells. After some thought, I see no advantage to do it and perhaps some over- or under-charging issuess. -- Regarding any use of the NiMH or NiCad setting for Li-Ion batteries (just in case someone misinterprets what we're talking about), it is a very dangerous idea from what I read. When I charge my Li-Ion I always check and double-check the display to be sure it says "Li."

Vince -- I am using a 168a that came with my McGizmo "Xenergy Moddity." I think you are referring to my make-shift way of connecting to the cell. Yep, Litfuse's setup is much better than mine. Someday I'll build or buy something for my little charger.

Paul

 

[Brock]

Yup, charging Li with Ni setting is a BAD idea. I would also think there would be overcharge or undercharge issues using the LI setting for Ni bat's.

 

[Willmore]

I've had a 777+][ for over a year, now. I chargec Ni cells at ~800mA*h and Li-ion cells at a variable rate starting around 800mA*h as well, but then tapering off. I've used it to charge 2.8A*h NiCd banks, 10A*h Li-ion banks, and a variety of Ni and Li packs for my many amateur radios. I've been very happy with it.

I guess I don't have the 180 minute shutoff problem that's been reported, elsewhere.

I do have the noise on charging Li-ion cells. I just assumed that the SMPS that forms the current regulator in the charger is changing through a range of duty cycles as the charge state progresses and that is what is causing the tone to change pitch. It bugs me a little, but then a turned on TV bugs me.