Tell me more ×
Electrical Engineering Stack Exchange is a question and answer site for electronics and electrical engineering professionals, students, and enthusiasts. It's 100% free, no registration required.
up vote 1 down vote favorite

Opened up one bike light from china that charges via a USB port (5V, .5A) and inside, the rechargeable battery is a barely labeled "R6P AA size 1.5vols 0% mercury". besides that only engrish, brands and a warning "Do not dispose in fire, re-charge, put in backwards..."

I couldn't find anything from the R6P type, only alibaba.com (china wholesale ebay) sales. So i'm assuming it's an zinc-carbon AA-R6 for now.

If so, i used the bike light for almost a year with that battery inside it (not serviceable) recharging every week or so. what's the magic?

the control board has some ICs with black epoxy, i'm in the process of scrapping it.

share|improve this question
The black epoxy is probably protecting the IC. They took the die and wire bonded it directly to board and epoxied it in place, there will not be a chip underneath, probably. – Kortuk♦ May 21 '12 at 7:29
Alkaline batteries have degree of rechargeabilityy - iomproved by charging with "dirty DC" - pulsing DC with a proportion of discharge per mains cycle. Cycles are limited and capacity is also low. Not ideal or anywhere as good as a proper rechargeable battery. – Russell McMahon May 21 '12 at 10:25

1 Answer

up vote 2 down vote accepted

Alkaline batteries have a degree of rechargeabilityy - improved by charging with "dirty DC" - pulsing DC with a proportion of discharge per mains cycle. Cycles are limited and capacity is also low. Not ideal or anywhere as good as a proper rechargeable battery.

Carbon zinc (non alkaline) are AFAIK not as good as Alkaline at being recharged.

It is a regrettably common occurrence for items made in China to cut corners or to fraudulently use components that have no chance of meeting the claimed performance. It is quite likely that your battery is in this category. Some equipment ios wrongly labelled and does actually meet the intended spec = but this is less common.

Here are some R6P AA batteries advertised on Alibaba - they are Manganese Zinc - not rechargeable.

share|improve this answer
thanks for the good info! but it was a false alarm, the battery had the wrong markings. while messing with the system further (want to use the lasers somewhere else), i noticed some components require way more than 1.5V, checked the battery, it had 3.6V... removing the wrapping, i found the small board common on protected li-ion batteries. So i'm assuming they used the wrappings from the wrong battery. maybe because it would be a internal non-serviceable cell, they bought some bad lot from the factory or something. who knows what happens in china. – gcb May 23 '12 at 18:00
@gcb - I know what happens in China :-). I've spent many months wandering through Chinese factories and seeing what happens. Most enlightening. – Russell McMahon May 23 '12 at 18:40

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.