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View Full Version : MAHA CH-9000 Wizard One and FujiCell 1000 - Big Problem


Spoon
2007.03.16, 07:44 AM
I figure with the latest buzz on the forums about chargers and batteries there would be several people trying this combination. I was breaking in some Maha 1000's and I just happened to be near the charger when I heard a short hissing sound.

It took me a couple of minutes to figure out what it was because it smelled like burnt electronics and I was smelling all of my Z's and power supplies to see if I coudl find it.

Turns out one of the batteries in my Maha WizardOne got really really HOT! The plastic on the MAHA chargind bay is deformed and I had to use plier to get the battery out. Most of the damage you see on the wrapper is because it was pretty mcuh liquid when I used the pliers and it deformed when I grabbed the battery.

This was setup on a ceramic tile in front of two fans. The break in prcedure (100mA @ 16 hours) is exactly what fujicell calls for in their data sheet.
http://www.mini-zracer.com/forums/attachment.php?attachmentid=22153

http://mini-zracer.com/mini-zgallery/data/722/medium/maha-fuji01.JPG http://mini-zracer.com/mini-zgallery/data/722/medium/maha-fuji-2.JPG

arch2b
2007.03.16, 08:01 AM
:eek: any guess's as to what failed? have you contacted maha or the retailer regarding a replacement? do you place a fan directly over the cells or just infront of the charger? if it got that hot i doubt a fan on the cells would have made any difference though.

fyi, i ran all my fuji 1k's thru the refresh in my bc-900 @ 200-500 and never got a hot cell. it took atleast 24hrs for the average cycle to complete so i think i may have selected 200.

Spoon
2007.03.16, 08:08 AM
No idea what failed. I had two fans on the charger. The one on the side of my pit box and a small box fan that I use when soldering (so the wife doesn't think I am breathing in noxious lead fumes).

I actually contacted Maha about another minor issue with the charger. I was waiting for this cycle to finish before I took the pictures (for the other thing). I sent an email to Maha this morning. They are in CA so I don't expect an answer for a few hours at least.

I also did a few sets on the BC-900's with no problems. Probably @ 200. Having 4 chargers going at once is what made me use the box fan. ;)

arch2b
2007.03.16, 08:53 AM
it took me over a week to sysle all of my fuji 1k's.

reaffirms my belief that no matter who makes what, there are always going to be issues :( we all know about the complaints with the bc-900 and i am always skeptical about overly glamorous reviews of competing chargers for the simple fact that not everyone has the same experience with the same product. it's almost refreshing i'm sad to say as it reaffirms my belief that all things being equal, both chargers have the same potential for faults. considering i've had to return a bc-900 already, i'm still happy with it though and i'm sure that while disappointed with this event, you will likely be just as happy with your maha chargers.

sorry, i did not mean this to be yet another comparison. i'll end that discussion here and now.

could you post the support information for maha and keep us posted as to your experience with thier support services?

Spoon
2007.03.16, 09:13 AM
Not to make this a comparison thread...but you are correct. Not everyone's experience is going to be the same with every product. I have been using the Ver 32 BC-900's for almost a year with absolutely no problems.

Getting back on topic :p

I went through the MaHa website to contact customer support and got a response within 24 hours. I'll post updates as things progress.

I was just about to post a "first impressions" post on 128racing (http://128racing.blogspot.com) but I think I'll hold off for a few days to see how this gets resolved. I have no doubts that this is a great charger but whatever happens over the next few days will probably help shape my "first impressions". ;)

Sinister_Y
2007.03.16, 10:39 AM
Sorry to hear that man. I've been running my 4 chargers non-stop since I got them...seriously. They've been on for about 2 weeks solid now.

I've got no problems so far. I do hear noises from the chargers (like spurts). It's hard to describe. This noise did alarm me at first, but then I figured since all of the 4 chargers did this with all different types of cells, this was normal.

Good luck and keep us posted.

Spoon
2007.03.16, 10:46 AM
Yeah, I think I know the sound you are talking about. I notice it when I first configure the batteries. This was sort of like a very empty can of compressed air. That's actually what I thought it was because I had a very empty can of compressed air in a pile with some other trash. :p

Are you using the fujicells?

One more question. Do you have any problems with any of the cells seating correctly? On one of my slots the negative tab sometimes "shifts" just a little bit, then it doesn't contact the battery anymore. It's really really subtle.

Sinister_Y
2007.03.16, 11:42 AM
I haven't taken delivery of the cells yet. They're sitting at my brother in law's house in Florida waiting for pickup.

No problems with batteries seating, unless you count very snug. They all make a "pluck" sound when extracting them from the charger. It's pretty tight, but I imagine after time, things will loosen up.

The break-in work that you were doing, didn't you just select "break-in" and select 1000mah? When you are referring to 100mah (fuji sheet has 93mah if I'm not mistaken), this is what the charger selected automatically? or did you override somehow?

Spoon
2007.03.16, 12:42 PM
I selected "break-in" and 1000mAH and it automatically selected 100mA. I know it's not exactly 93 mA but it's within a couple of percent. I wanted to check the datasheet just to make sure it didn't have a minimum charge current that was like 0.2C or something.

By the way, here is the response from MaHa

Thank you very much for the pictures that you have uploaded. It is safe to say that the charger you have is defective. Right now, I am testing a brand new C9000 that I will be sending to you. So far so good. Hopefully I can get it to you by today if not I will make sure this will go out for you first thing in the morning. Could you please reply back with your shipping address so I can send you the charger and a UPS Return Label for the defective charger? Thanks in advance, I look forward to hearing from you.

arch2b
2007.03.16, 01:02 PM
thanks for the update.

just as important to me as the quality of the product is the quality of the support services. even though i had trouble with my first bc-900, the support service was excellent.

rharris
2007.03.16, 01:19 PM
Thanks Arch,

Sorry for your trouble, but it's good to know MAHA stands behind the product.

shuter
2007.03.16, 03:04 PM
WOW that battery was really hot. Could have had a fire there. We use so many electronic gadgets every day we tend to forget that they can malfunction with serious consequences. I'm going to move my chargers from the china cabinet shelf to a more fireproof location for charging batteries unattended. There are multiple heat sensing features in the charger, one wonders why the charger did not shut down.

The MH-C9000 does make little noises. I remember reading somewhere what they were but can not racall the explanation or where I read it. I just remember that they were normal and disregard them.

Spoon
2007.03.16, 03:32 PM
WOW that battery was really hot. Could have had a fire there. We use so many electronic gadgets every day we tend to forget that they can malfunction with serious consequences. I'm going to move my chargers from the china cabinet shelf to a more fireproof location for charging batteries unattended. There are multiple heat sensing features in the charger, one wonders why the charger did not shut down.

The MH-C9000 does make little noises. I remember reading somewhere what they were but can not racall the explanation or where I read it. I just remember that they were normal and disregard them.

That's a good point about the heat sensing. Not really sure what happened. Maha is going to test the unit to see if they can figure it out. I typically charge my batteries in front of a fan and put them on top a ceramic tile. It's not really fireproof since it's so close to a wall and could easily flame up and burn down my house (not an exciting thought). I am going to look into something a little safer. There is an unfinished part of my basement that's just a concrete slab, I guess I could charge stuff there...

arch2b
2007.03.16, 06:18 PM
i always leave my charger on a 16x16 ceramic tile when unwatched at home. if any of the dc club people want one, i have many more left over from the basement construction.

shuter
2007.03.16, 06:39 PM
i always leave my charger on a 16x16 ceramic tile when unwatched at home. if any of the dc club people want one, i have many more left over from the basement construction.

Sounds like a great idea. Where do you get such an item? Home Depot?

arch2b
2007.03.16, 06:50 PM
check any flooring/carpet/tile store. you can ask for any samples, disconintued lines to see if they will give you a tile. i don't hink you can buy them individually. they typ. come in boxes but i'm sure you could get some cheap tile from home depot of the like. you may even find a 24x24 tile

Spoon
2007.03.16, 06:57 PM
I got a couple of 12 x 12 tiles at Lowes for like $1 each.

shuter
2007.03.16, 08:19 PM
Thanks Arch & Spoon, I'll pick up a ceramic tile next time I go to town.

You know, a few months ago when I first started looking into chargers I ran across a couple of accounts on forums/blogs of chargers melting. One even bursting into flames. I just ignored it then but it feels a lot more real to me now with Spoons mishap.

soyverde
2007.03.19, 10:58 AM
Interesting that this occurred at a lower charge rate. Sounds pretty similar to the BC-900 issue, which typically occurred when charging at a lower rate with high capacity batteries (the delta peak is a lot less apparent, and therefore easier to miss, at charge rates below 0.5C).

I charge my batteries on a metal plate on top of a speaker (not directly touching a wall). It isn't exactly foolproof, but the battery would have to really explode (or tip the metal) to hit anything flammable. Of course the fire could just follow the cord to the wall. :p

Spoon
2007.03.19, 11:02 AM
It does sound familiar to the BC-900 issue. The Maha is setup to charge at 0.1C for 16 hours. So for that particular mode I don't think it uses a detaV cutoff.

I have been watching the rest of my batteries closely and everything stays pretty cool. I am expecting a replacement from Maha shortly.

soyverde
2007.03.19, 11:58 AM
Interesting...so the Maha has a timed-only setting (I assume with temperature cutoffs), and the spec sheet actually said to put ~1500 mA into the battery on the first charge? I cycled these Fujicells in my BC-900 and the first batch only rated ~600mAh with a simple 'test' (charge, discharge, recharge) at a 700mAh rate. I ended up refreshing both sets I picked up (most are rating in the 900s now).

I have always heard excellent things about Maha's customer service, so their response isn't surprising (though it's still good to see another story confirming it).

Edit: Do you have a link to the spec sheet? Any notes on discharge as well?

Spoon
2007.03.19, 12:23 PM
Interesting...so the Maha has a timed-only setting (I assume with temperature cutoffs), and the spec sheet actually said to put ~1500 mA into the battery on the first charge? I cycled these Fujicells in my BC-900 and the first batch only rated ~600mAh with a simple 'test' (charge, discharge, recharge) at a 700mAh rate. I ended up refreshing both sets I picked up (most are rating in the 900s now).

I have always heard excellent things about Maha's customer service, so their response isn't surprising (though it's still good to see another story confirming it).

Edit: Do you have a link to the spec sheet? Any notes on discharge as well?

Yeah, the break-in function is 16 hour charge ar 0.1C, rest 1 hour, discharge at 0.2 C, rest one hour, charge at 0.1C. It's kind of like the test on the BC-900. You just input the battery capacity.

A lot of my fuji's are coming in between 910 and 950. I still have to get through all of them.

Here's a link to the Maha instructions. I think they say that new batteries should get a "conditioning" charge. That's what the break-in is all about. That was kind of new to me.

http://www.mahaenergy.com/download/mhc9000.pdf

I'll probably attach that pdf to the Maha 9000 thread.

soyverde
2007.03.19, 12:38 PM
I'm surprised it doesn't discharge before putting 1.6C (over time) into the batteries.

Here is a bit more info from CPF: http://www.candlepowerforums.com/vb/showthread.php?t=145727

Edit: There is some very interesting discussion to this effect in that link. I would definitely be discharging before putting 1.6C into my batteries.