jbryant

Hi peoples,

I've recently invested in a Uniross charger (Argos link)as several of my son's favourite toys require batteries and we seemed to be getting through a huge number of AAs. Though this is a pain, you can get massive packs of AA batteries for a few quid in most stores like Toys'r'us.

One of the main reasons I went for the charger in the end was because his Fisher Price cot aquarium (bubbles, light music and muted lights) requires 4x D Cell batteries and this tends to come in at £7-8 for a set every 5-6 weeks. Rechargeables should soon pay for themselves.

Now with rechargeables, the Nickel Cadmium batteries are only lasting just over a week on a full charge. Not only that but when they go, they drop off so quickly that we can't predict that the machine will fail on his next sleep, leaving the more little tyke with no music to sleep to!!

What's going on? I wasn't expecting Duracell type staying power, but at least 50-75% of a normal battery life as a minimum.

Can anyone suggest what may be going wrong? I can only assume the batteries are empty before I recharge them as the machine is close to death

Thanks for any help you can offer
Joolz

mark_h

What capacity are the batteries? Look for a mAh number on them.

If you can, get high capacity NiMh (Nickel Metal Hydride) batteries, which last longer than NiCds, and don't suffer from the "memory effect" that NiCds have.

I have some old NiCd AAs lying around that are 600mAh, but I'm now using some 2200mAh NiMH AAs - almost 4 times the capacity

Have also just found a really old set of NiCd D batteries with 100mAh capacity and I can currently buy NiMh D batteries with 2200mAh capacity or even 7000mAh capacity - although these are £7 each!

Allan

iTrader: (1)

You might get an improvement from some high quality NI-MH cells, I use GP which are very good. Look for the highest capacity that you can find, this will be identified for example as 2200mah, the higher the number the longer they will last.

Try “RS components” or “CPC”.

Allan

Allan

iTrader: (1)

LOL, I was typing my reply and got interupted, you beat me to it Mark

jbryant

I should have said this is my original post - These are brand new 'high-performance' batteries
- Uniross NiMh 2300's £7.99 for 2.
That's why I'm so surprised at the crap performance
Was thinking they may need to 'warm up' but they've had 3 full charges now...

Is there a possibility that I have some dodgy batteries? I'm tempted to buy some more but don't want to waste more money as I'm already in trouble over this with my boy

Thanks
Joolz

Allan

iTrader: (1)

Joolz, I don't personally rate Uniross, I would say it's worth the gamble to try a different brand. look for those 7000mah.

Allan

imlach

Rechargeable batteries tend to maintain a high percentage of their optimum voltage across 90% of their charged state...

Hence why they run out without much warning.

Alkaline batteries tend to slowly decrease voltage over time....hence why you get a bit of warning.

If they last 5-7 days, recharge after 4 days. Get 2 sets and swap every 4 days. You will learn how long rechargeables last in the products you are using, and learn when to swap them to ensure no loss to your baby.

Just takes a bit of discipline.....

mark_h

I sometimes use these for batteries: Budget Batteries. They sell a 7000mAh D battery.

Joolz, have you tried charging your batteries twice in a row? Some chargers can't charge high capacity NiMh batteries in one go because they take too long and the internal safety timer cuts in - I have to put my 2200mAh AAs on twice to fully charge them.

jbryant

Good advice and thank you!

The wife has just run off to the garage and paid £8 for another set of Duracells! While they are in the baby toy, I'll now have the chance to run the current batteries through 2 or 3 times so they are definitely fully charged (currently there is only time for the charger's recommended 8 hour cycle before they need to go back in the machine). If multiple charges makes a marked improvement I can go out and buy another set of 4 rechargeables with confidence.

imlach - I would be happy to charge the batteries every 4 days (PITA) - but not if the non-rechargeable alternatives last 6 weeks!!!

Cheers
Joolz

PS. I can't belive that site is charging 32pence for some of the cheaper batteries

GaryCat

I got a pack of 12 1800mAh rechargable for £9.99 from maplin.co.uk - superb value as they were on offer at the time. They are now £15

http://www.maplin.co.uk/Products/Mod...leNo=-546&MR=N


If you use them in toys with motors like r/c cars they will discharge quickly, but the car will go faster

imlach

Lazy sod
Think of the environment! 10 seconds to swap batteries.....how hard is that? You want to throw money down the drain?

jbryant

HAHA I see what you're saying, and I AM a lazy sod but the aquarium has 7 totally threaded screws from all the battery changes already, and the batteries are really difficult to remove from the machine. They're totally wedged in even after the battery plate comes off!

There are motors in this thing, making bubbles and making a few fish 'swim', but it was the huge disparity between performance of the rechargeables and the standard Duracell types that had me raising the question.
But thanks for the link - I'm off to buy some of those AA's now

Cheers
Joolz

imlach

Ah, pain.
Why can't these things be designed properly from the outset - I guess it's to stop babies getting at the batteries, but why not design it with recharheables built-in and a charging socket. Literally pennies to manufacture it this way.

This sort of thing is quite annoying.

mark_h

If the aquarium doesn't move, couldn't you get a 6V mains adapter? If it hasn't got a mains adapter socket, you could wire it straight onto the battery terminals. As long as you can make sure the cable won't get pulled out.

jbryant

I'm amazed that something so hungry on power does not come with a mains adapter! For the sake of another £2 on the £20-£25 sticker price.

Although a fine idea for other appliances, I don't like the thought of my 19 month old son pulling and kicking at the wires for 12 hours a night without my knowledge. Doesn't seem worth the risk at any cost... Perhaps that is why they've not included an adapter as this thing is designed to be attached to the side of a cot and therefore trailing wires (way too much of a temptation I expect) are unavoidable.

Joolz

farmer1

Dunno if it has been said but nickle metal hydride batteries tike 5+ charges to reach their optimium performance.

brickboy

Sort of on-topic, why do so many battery-powered kids toys etc say "don't use rechargable batteries" on them? We've got a few remote-control toys that specifically say this, but I've been using NiMH rechargables in everything for ages and no problems.

Also, what would happen if you put a flat Duracell in a Uniross charger? Would it overheat / burst? Or would it charge up?

Leslie

Ni-Cad batteries only produce 1.2 volts per battery instead of 1.5V for a normal AA cell. Also when the batteries start to run down they lose the voltage much more quickly than normal or NI-Mh cells. As was mentioned you have to get high capacity batteries as well which are more expensive. If you recharge Ni-cad batteries before they are run down they also develop a memory which reduces the charge capacity.

Les

Brendan Hughes

One final thing - check your charger is set to charge NiCads. If it is switchable, and is set to charge NiMH instead, you won't be doing them any good at all.