UK METAL DETECTING

EdUK · Joined: 23 Jul 2007 Posts: 79 Location: Kent

I just bought a couple of these complete with intelligent charger from a shop on fleabay - total was £15.10 delivered. I am going to be out of action for at least a couple of weeks (having my feet worked on today) but I can't wait to get out there and try them out !

Does anyone know if there is any advantage or disadvantage to using the discharge feature of the charger before charging them ? This is built in btw - you press the button and an lead lights to say that it is discharging - when it is ready , it switches automatically to recharge them. When they are charged it switches to trickle charge so as not to cook them.

Edwin

UK Brian · Joined: 08 May 2007 Posts: 431 Location: Wales

They are pretty high power so thats a good price including an intelligent charger.
As for the discharge feature I ran two sets of batteries alternatively for over two years. One set I discharged and allowed to charge, the other I just charged.
Up to date both sets are giving about the same running time so I don't seem to have gained anything. According to the experts its best to discharge but it hasn't made any difference so far. Where it would make a difference is if you tend to run batteries half flat then recharge.

Must mention I had a senior moment and put NiMi's in my XLT rechargable holder when the batteries failed without it striking me that the dedicated charger is for NiCads only.
Three years on its still the best battery set/longest life and nothing has exploded. I do charge it with the battery in a ventilated tin just in case !

malachite · Joined: 02 Jul 2007 Posts: 203 Location: The Toon

if memory serves NiMh batteries are memory free anyway so in reality they shouldnt need discharging unlike Nicads..

EdUK · Joined: 23 Jul 2007 Posts: 79 Location: Kent

Thanks for that guys - that is what I thought and I did have a trawl around the net looking for guidance with no joy. I have run the discharge feature on the batteries that I already own - will probably do it with the new ones for the first few cycles but after that not bother. I really like the fact that it does it all automatically - you just pop in the cell and press the discharge button and a few hours later it is on trickle charge ready to use.

UK Brian · Joined: 08 May 2007 Posts: 431 Location: Wales

The latest research from the States says

" The NiMH cell costs more and has half the service life of the NiCd but also has 30% more capacity. The memory effect which was at one time thought to be absent from NiMH cells is present if cells are not treated correctly.
To avoid the memory effect discharge every 30 or so cycles."

Two things I've just thought of. NiMH's don't take a full charge from the off. Performance/run time will get better after you have used and recharged them a few times. Plus new batteries have a much higher capacity than those of a few years back.
This has two knock on effects. First if you have an older charger it is unlikely to have the grunt to fully charge a new high power cell. Best to get a new charger though extended periods on trikkle charge do help.
The big plus with this is that many of the rather heavy older machines can be fitted with 8 or 12 AAA's in place of the original 8 or 12 AA's. This can save quite a bit of weight. Normally a shorter run time and some machines won't like it full stop and then you have to consider if its worth using a couple more of the smaller cells which reduces the weight gain.

I don't know if the situation has improved but in the past I've had to bring 10 cell holders back from the U.S. as I couldn't get them here.

EdUK · Joined: 23 Jul 2007 Posts: 79 Location: Kent

That's good - thanks for that. I am glad that the discharge feature on the charger will not be wasted.

kered · Joined: 29 Sep 2007 Posts: 97 Location: NW Spain

Hi Ed, i'm interested in those 280ah battereies for my tesoro golden umax, how are they holding up thier charge?
I've got a Duracel Ultra in at the moment and have used it for some 25 hours plus a couple without the headphones and i still get 4 beeps on the battery test so they seem pretty good but once they are done they are done and they are not cheep(6.5€)
from the ebay price, 4 are cheaper than 1 duracel(not counting postage) so i was just wondering how you got on with them

EdUK · Joined: 23 Jul 2007 Posts: 79 Location: Kent

Good morning. I have swapped my trident 1 for a trident 2 now and that loves the NiMH batteries as well. I am still delighted with these batteries - they hold their charge really well even when not in use which is a new development for rechargeables. I never go below 8 beeps myself - that's a few hours detecting and then I stick them back in the charger for a run down and recharge which it does automatically. I have 2 batteries which is plenty in terms of hours in the field. My ones are made by Vapex - they have a website that you can look at the specs on. I will PM you the seller id.

Ed

kered · Joined: 29 Sep 2007 Posts: 97 Location: NW Spain

Cheers Ed, got your PM, this one only has 7 beeps on a new battery, must be different beeps according to model.
These lithium polimer look promising too ebay Item number: 190166761849, bit stiff on price, though they have the charger and batteries to buy seperately.

Still havn't made up my mind to get the AA conversion or go for the 9v rechargables Confused

EdUK · Joined: 23 Jul 2007 Posts: 79 Location: Kent

Those LiPo batteries do look good but I doubt if there is anything to be gained over the vapex NiMH. I did think about an AA conversion myself - what put me off mainly was the weight and the fiddling around to recharge 7 or 8 AA at a time. At least sticking with a PP3 - it only takes a few seconds to pop it into the charger and you are good to go again.
I think my trident does 7 or 8 bleeps with a duracell but 9 or 10 with the NiMH. I spoke to a pal who is into electronics and he reckons that is to do with the better current delivery of the rechargeable over the throw away.

kered · Joined: 29 Sep 2007 Posts: 97 Location: NW Spain

Just bought a couple and a charger, at worst i can use them in my incubator hygrometers and other stuff i have if they don't perform,
I'll let you know the result

EdUK · Joined: 23 Jul 2007 Posts: 79 Location: Kent

I think you will be pleased. They worked really well in my trident 1 and trident 2. I think they are superior to chuck away batteries and far more cost effective.

UK Brian · Joined: 08 May 2007 Posts: 431 Location: Wales

Ed, re your earlier post. Unless there's some great brealthrough been made recently NiMi's discharge faster when not in use than NiCads (they call them frequent use batteries).
So will be fine as your using the machine regularly but if you end up with several then NiCads can be a better choice.

Brian

EdUK · Joined: 23 Jul 2007 Posts: 79 Location: Kent

Thanks Brian but I checked on the vapex website and these ones retain at least 80% of their charge for 2 years.(this seems to ring true with my findings) I was pleasantly surprised - things do seem to be moving along in terms of battery technology. I don't take any chances anyway - I cycle them the day before using them.

kered · Joined: 29 Sep 2007 Posts: 97 Location: NW Spain

Batteries + charger arrived this morning with a free plug adapter too Very Happy

, as the charger has the UK square pins, Very good service from the guy and at 3.50 postage to spain, probably cheeper than UK next day service.

itl-e is the sellers name, i think he deserves a mention if only for the quality of service
this is his ebay shop http://stores.ebay.co.uk/component-shop for anyone else interested