My wall clocks require monthly battery change?!! V.Expensive.. Help

27col

I agree about having accurate clocks, but if having a clock that is a minute out means that you miss a train then I would suggest that the OP is cutting things rather too fine in the morning. Or you could set the clock 5 minutes fast and thus leave the house in plenty of time to catch the train. Incidentally, we have never had a battery powered clock where the battery did not last for best part of a year. Never used a battery that didn't come from a cheapo shop or the market, either.

savedmoney

Thanks for all the replies.

I am intrigued by experiences posted here confirming that BOTH my clocks do indeed seem to have an issue.

I am going to try to see if I can make my clocks usable with these rechargeable batteries
Hybrid - The Next Generation Rechargeable Battery
http://www.maplin.co.uk/Module.aspx?ModuleNo=219932

According to the product info they should be perfect for the job.
My expectation is to be able to get into a routine of charging up the batteries every few months.

robpw2 wrote: »

sell the clocks and buy a cheap one

These clocks are perfect for my usage... except for this one major glitch.

Will post the results of my experiment with rechargable batteries.

Inactive

I am not convinced that clocks require such a high output battery as those on Maplins, clocks are low drain items.

These are a lot cheaper, but of the same type;

http://www.7dayshop.com/catalog/product_info.php?products_id=107341

Lower output, but as I say, I don't think that a clock needs a high output power source.

Frank_E

savedmoney wrote: »

Thanks elsien and Frank E,
I had considered rechargeable batteries, but as Frank E mentions the 'accepted wisdom' is that due to self-discharge they are not suitable for wall clocks.

I should have clarified that standard NiMHs have high self discharge. Hybrid NiMHs have low self discharge but you may find that their capacity (way lower than Alakaline and I think still lower than regular NiMH) is not high enough to allow your clock to run for long enough. I might have got lucky with a new 2700mAh Ansmann NiMH in my wall clock.
As a frame of reference the 2300mAh NiMHs lasted about 6 months in the Aldi RC clock the last two months were dim, whereas Duracells last well over a year. I bought a few John Lewis RC clocks in the January sales this year to replace that clock and they are still going strong with the supplied alkalines.

I would say they hybrid NiMHs are very well suited to wall clocks, they just aren't well suited to wall clocks that go through alkalines in 1-2 months. It depends of course how critical having those particular clocks working is to you.
[QUOTE=savedmoney;39665802
So much for accepted wisdom, I think I will give rechargable batteries a try can't be much worse then the current 1-2 months with my one use Energizer/Duracell Alkaline batteries.
[/QUOTE]

No matter what chemistry of rechargeable you try to run your clock on you will have to change them more often.
Standard NiMHs would self discharge before you got the good of their capacity.
Hybrid NiMHs would simply run out of capacity well before alkalines would.

It depends if your clock is critical or not and if the issue is repeated purchase & disposal of batteries or if it's the length of time the batteries last (regardless of battery cost). If you don't mind changing the batteries more often than you currently do to save on wastage then by all means try them.

Though the low self discharge of hybrids approaches the 'ideal' of alkaline, the capacities are lower. Your alakalines are running out of steam because of the the relatively high drain from the clock and the capacity (mAh) rating of the battery not being high enough.

Chemistry Capacity Self discharge
Alkaline high very low
Regular NiMH high highest
Hybrid NIMH not so high low

I couldn't quote capacity figures for alkalines as it is so long since I've bought any. Odd that the manufacturers don't quote capacity on their packaging and adverts. If you did get rechargeables, you could use them for other applications if they don't work out in the clocks. They won't.

[QUOTE=savedmoney;39665802
A few questions before I try it out
Frank E and any other helpful MSE DIYers,
- Is there a particular type of rechargeable battery brand which you might recommend from experience for clock usage?
If you know of an online retailer a link would be appreciated
[/QUOTE]


NiMH batteries AAA-D for high drain applications digital cameras, flashlights etc where self-discharge is not an issue
Ansmann
www.ansmann.de
I have used their NiMH cylindrical batteries AAA to D extensively for over 10 years.
Used their 9V NiMH batteries extensively too until I found IpowerUS Lithium 9V.
Uniross: bought some of these when I was away and they didn't last so many cycles.

Hybrid NiMHs low self-discharge applications (remote controls, low drain clocks (i.e. not your clocks) )
Ansmann max-e
http://www.ansmann.de/cms/businessdivision/consumroot/batteries-battery-packs/rechargeable-batteries-nimh/maxe-accu-battery.html
Eneloops
I've not used other brands of hybrid.

9V rechargeables
I Power US Lithium Polymer 520mAh (highest NiMH capacity on a 9V E I'm aware of is 250mAh)
I got these from a broadcast hire firm, who supply them with broadcast radio-mics. I thoroughly recommend them. Expensive though but they came with a fast compact charger which manages each battery independently, a caddy.

If you do move towards using recharegables for general use, not for your battery chewing clock I would recommend a good charger which supervises each battery independently and has delta V control eg the Ansmann Energy 8, the Lacrosse BC 900. I wouldn't recommend the fast wall socket chargers that you have to put a pair of batteries in for them to work, they destroy batteries. Leaving NiMHs on trickle also reduces the lifespan of batteries.

I'd also recommend decent battery storage once you accumulate batteries such as http://www.powerpax.net/products/

Retailers I have used
www.BudgetBatteries.co.uk
www.Tantronics.co.uk
www.richmondfilmservices.co.uk (for 9V 520mA Li Poly batteries only, they are a sound equipment hire co)

savedmoney wrote: »

-2700mAh was mentioned, is it the case that a particular mAh rating would be better (eg last longer between recharge), is it higher or lower for this type of use?

The higher mAh rating of a battery the better. The last time I bought batteries about a year ago 2700mAh was the highest capacity rechargeable AA battery on the market.

savedmoney wrote: »

-You mentioned NiMH, I know the basics about rechargeable batteries but would a particular type of battery (eg chemistry type) be more suitable for wall clock use?

Alkaline due to high capacity (mAh) and low self discharge. Hybrid NiMHs (but only if your clock is low drain). It isn't.
Lithium polymer would be ideal but they are not available in AA or any cylindrical (1.5V) size because of their inherent voltage 3.7V.

savedmoney wrote: »

Thanks much appreciated

You're welcome.
I like to encourage people to use rechargeable batteries but only where they are appropriate. I really don't think rechargeables would be useful for your clocks though I recommend you consider investing in them for other uses (this is a money saving forum after all).

[Edit: didn;t see the title of the thread when typing this response. Since the expense appears to be the main issue then I would recommend hybrids for saving money in the application, though you may still be charging the batteris often]

savedmoney

Thanks Frank E

Shall be archiving your v.informative post, have been planning to make more use of rechargable batteries for a while. Will definetly be some serious MoneySaving :money:

Will post on what happens on my attempt to tame my wild clocks.

stevemcol

I don't think this is a battery issue. I just think the clocks aren't too accurate. Have they got a compensation adjustment on the back? If not, you could try radio controlled clocks.
I've got one in the kitchen and haven't changed the battery yet. Second perfect and self corrects for BST/GMT.
Here

nevile

Selling it would be the better option.

maninthestreet

stevemcol wrote: »

I don't think this is a battery issue. I just think the clocks aren't too accurate. Have they got a compensation adjustment on the back? If not, you could try radio controlled clocks.
I've got one in the kitchen and haven't changed the battery yet. Second perfect and self corrects for BST/GMT.
Here

Two different quartz clocks that are 1 or 2 minutes out after just a few weeks sounds unlikely to me.