Problem with Sanyo 2700 NiMH

[technology]

Hello,

I have few Sanyo 2700 batteries and having performance issue(s) which makes them not usable. These were bought from a well known shopping mall in Singapore and not used for months until recently. It does not seem to hold the charge, not even for two days (when not used). I agree that 2700 has one worst discharge rate but not an extant of two days. I'm sure they are charged fully with GP quick charger since it takes little longer than the Sanyo 2100s (Using 2100 for years without any problem). I have tested a fully charged set by drawing 0.8A using a LED and it does not last more than 35 minutes but I must admit, I don't have a charger in rank of C9000 to evaluate them properly. Few months back I made a case with Sanyo energy – Singapore to investigate the issue. After few rounds of talk, they have advised my country's distributer to look into the problem but to my disappointment, there were no further communication from the Sanyo Singapore as well as from the local distributer. I had sent repeated emails to Sanyo Singapore but no replies.

Few pictures of Sanyo 2700 as you notice the wobbled text.







I would like get your advice on how to take this further.

Many Thanks.

 

[Mr Happy]

I know it's disappointing to buy things that don't live up to expectations, but I doubt there is much you can do except put it down to experience and move on.

You have not been very precise about what time periods are involved except to say "months". How long did the batteries actually remain unused after you purchased them?

2700 mAh batteries are fragile, and they can fail in ways that result in very high self-discharge and loss of capacity. Storing them for a long time unused might lead to this.

I think if you are buying 2700 mAh batteries you need to buy them with the intention that you will charge them and use them frequently, that you really need the extra capacity, and that you are prepared to live with the cost of replacing them if they fail early.

For ordinary batteries for every day use I strongly recommend eneloops. They are much more durable and long lasting.

 

[technology]

Thanks for your advice - Mr Happy.

These were stored in its original pack for about 6 months under normal room temperature(~20c) before they are opened for the use. Does these cells have any expire date/"Use it before" time frame ? Its hard to imagine all the 6 pieces failing at the same time.Are these any particular batch issue? I don't remember Sanyo recalling any 2700s.

Yup, The enloops are the way to go and I'm waiting for the availability of upgrade eneloop here in my country.

 

[Mr Happy]

I'm not sure about those cells specifically, but Sanyo cells often have a manufacturing date code stamped on the side near the seam.

A typical rule of thumb is that cells should be charged and used within about 12 months of the manufacturing date. When you buy cells you do not always know how long the stock has been sitting before you purchase it, so you can occasionally get old stock that has already been sitting for a year or more before you obtain it.

I sense a suggestion that that maybe the cells are not genuine, but I do not know how to tell that.

There have been reports of rapid self-discharge failure in Sanyo 2700 cells, as with other brands of 2700 cell. I suppose an ideal resolution for you would be that somehow Sanyo accepts that you return the cells to them for analysis and they replace them if they do not meet expectation. However, if you have not charged them with a Sanyo charger they may not feel obligated to do that.

Sorry. Sometimes these things happen and there is not much you can do.

 

[BatteryCharger]

I have had similar problems with Duracell 2650 batteries, which I believe are Sanyos. Out of several hundred samples, at least half of them won't hold a charge for a week. I'd be willing to bet a lot this is why all the major MFGs are going back down to lower capacity batteries.

2700mah is nice, if you're ready to use them hot off the charger sometimes though...I like to have a big pile of Duraloops and some other higher capacity NiMh. Each does something the other doesn't do...

 

[rookiedaddy]

Hello technology,
take a look at this thread that I posted last year >> http://www.candlepowerforums.com/vb/showthread.php?t=238652
Sanyo acknowledged that there was high self-discharge problem with some batches of the 2700mAh Sanyo Rechargeable. The problematic cells I had would self-discharge in a week. The replacements are so far OK. (speaking of which, I should go update a post in the thread reporting how it's performing...)