Battery charging queries.

[karlfrancis]

Hi folks,

Here's the questions! I read in a German RC Mag that you can buy battery chargers that 'recondition' batteries. I can speak German quite well but can't read it very well, (come on, I am Welsh)! Does anyone know of such chargers out there? I'd also like one that can charge more that one battery with a Tamiya connectors and that also has Peak Detection. This I'm led to believe is something that the charger does when the batt is full, it'll stop charging it. Anyone know the answers?!

Cheers,

Karl.

[raemin]

There are several type of charging techniques depending on the type of batteries. For NiCd batteries reflex chargin works the best : the battery is charged for 2/3 of a second and discharged for 1/3 of a second.

For most batteries type fully charging / discharging 3 times the batteries does revive batteries quite well. No miracle but the most appropriate way to get a battery ready for racing after a more than one month idle period.

A brute method is zapping, works both for NiCd and Nimh: the idea is to send a high voltage (30v to 90v) through each cells separately: this will break all the dendrite (also refered to as crystal) that are building up on the cathode.

[karlfrancis]

Hi raemin,

I have a mixture of Ni-Cad and NiMh. The way in which I use them is to use them until they are drained, (obviously) and then totally discharge them and then recharge them on a fast charger set to 1 hour. This I find works well but a couple of the Ni-Cad batts won't hold the charge very well so when I go to use them they're almost dead. I've tried disharging and charging again but still the same problem. Would this just mean that they're past their sell by date and should be thrown away?

Thanks for the reply mate.

Karl.

[raemin]

I presume your charger is just having some false peak. This just happends with old batteries or batteries that were drained beyond normal. Just try a slow charge at C/10 (eg a 3000 bat charged at 300mah) for 14hrs, discharge the battery, preferably on a tray, or alternatively on your car (but stop once power drops). After a few charge/discharge "cycles" your battery should get back to normal.

<<<< DISCLAMER : FOR BASHING USE / NOT FOR RACE >>>>

If this fail :

1-just find someone who can zapp them for you. I've just bought a zapper and I must say that the result is impressive.

2-Alternatively, discharge the pack (on your car), disasemble it and check which cell has gone down close to Ov and replace it (reversal syndroma). That's not perfect as the pack will not be matched anymore but for bashing it's Ok.

One last point: I do not recommend discharging old packs, as in most cases people do not use a tray and this lead to overdischarging the weakest element of the pack. The best is just to stop using your battery when the power drops and recharge from there. Do not discharge Nimh.

[BlazingDragon]

quote:

Originally posted by raemin

I presume your charger is just having some false peak. This just happends with old batteries or batteries that were drained beyond normal.

---

id="quote">id="quote">

It sounds to me like Karl's using an "old fashioned" type fast charger where you just leave it connected for a certain amount of time based on the charge rate and the capacity of the battery. In which case, his best bet is to buy a modern, peak-sensing fast charger that does both NiMh and NiCd...

Or, I could be totally wrong, and he maybe using a peak sensing fast charger, in which case ignore me

P.S. Karl, I'm from the Rhondda valley originally (town called Llwynypia) - it's nice to see a fellow Welshman on here, especially considering the recent Grand Slam []

[bholio]

quote:

I'd also like one that can charge more that one battery with a Tamiya connectors and that also has Peak Detection.

---

id="quote">id="quote">

Duratrax makes a charger which can handle 2 batteries, and I believe that Integy has one which can do 3 at once. Both of those are 'peak' chargers which will charge a battery until it is full automaticially. No timers. They monitor the voltage of the battery while it is charging and can detect when it is full.

[minijosh]

I use to use a Duratrax charger. It was one of the $50 ones so it wasn't the top of the range but you could set it up to either charger, discharge, quick chargr, or cycle the cells. Cycling will charge up the cells, then discharge, then recharge, then discharge, and so on and so on. Very good for older nicads. It will give them their life back.

[karlfrancis]

Thanks for some good feedback there folks, keep it coming as I think we'll all benifit from this. BLAZING DRAGON!!!! How are you butt? Nice to hear from you, not heard of your village but lets face it...........you'd only find some of them if you were lost!! I'm from one of em!

As for do not disharge NiMh. Why not? Does this damage them as I'm always discharging them. Someone said to stop when the power drops and to recharge from there. Is it not a good idea to prop up a car and let the power drain totally then? Please tell me this doesn't do any harm as this is what I've been doing up unitl I bought a couple of dishargers. The charger I'm using by the way is an ANSMAN ACT28 TRIPLE OUTPUT FAST CHARGER. It has a 12v and a 6v + & - bit with Transmitter above the 12v and Receiver above the 6v. I gather you can get rechargable batts for both Tranny and Receiver?

Black magic, that's what this hobby is........BLACK MAGIC!

C'mon the Welsh!

[karlfrancis]

Oh yeah, what on earth do you lot mean by 'zapping' a battery? The last 'zap' I had was when I tried repairing my washing machine, forgot to unplug it and ended up in intensive care. That did very little in the way of reconditioning my body!! So what is it then?

Karl.

[sosidge]

It's sending a very high voltage through the battery. Most matchers as part of the process, a handful of people do it to their old cells too.

[raemin]

Definitively do not fully discharge a nimh battery as it damages them.

[karlfrancis]

I'm not going to fully disharge my Nimh's anymore. The problem that I have is that I don't have a Peak Detection charger. If I put them onto my fast charger will they be 'over charged' and melt or leak? And how is the high current put through the batteries? Is it with a special charger?

Thanks for all the replies.

Karl.

[bholio]

What kind of fast charger do you have? Timer-style?. When batteries are overcharged, they dissipate the excess charging current as heat. They are damaged if they get too hot. If you keep close track of your batteries while charging and don't let them get too hot, you might be OK. However, who has time to babysit charging batteries?

Your charger should have the output amperage printed on it. It will be anywhere from 1-5 (or so) amps.

I'd recommend saving up and buying a good charger. This hobby is much better when you have one. Good deals can be found on ebay. You want a peak detection charger. Make sure it can do NiMh, as the older (and cheaper) ones can only do NiCd. The detection of the peak is different between NiCd and NiMh. A NiCD charger will not detect the peak properly and overcharge an NiMh.

quote:

Originally posted by karlfrancis

I'm not going to fully disharge my Nimh's anymore. The problem that I have is that I don't have a Peak Detection charger. If I put them onto my fast charger will they be 'over charged' and melt or leak? And how is the high current put through the batteries? Is it with a special charger?

Thanks for all the replies.

Karl.

---

id="quote">id="quote">

[karlfrancis]

bholio,

The charger I have says the following on the bottom:

Output:8.4v---3.0A 6.0v---70mA 12v---70mA

It doesn't say on it that it's for either NiCad or NiMh but I'm assuming that it's for Nicad. What I've been doing in the future is charging the batts for an hour, (on timer) or until all four of the chargers lights are lit. I do keep a very close eye on the batts and I do check to see if they're getting too hot. I had a batt leak and another on melted the plastic cover! I've read here in some of the feed back that I should stop using the batts once car performance drops. What I've been doing is to stop using the batt, put it on a discharger and then recharge the day before I intend on using the batts. I've since learnt that this is not such a good idea.

If I didn't discharge the batts and was to put them back on charge for an hour, it would most certainly overheat.

I think you're right though, I must buy a peak detection charger. I've just bought three LRP 3300 NiMh batts from ebay for Euros 38. This is quite cheap I think, the guy said they were only bought last November and used 10 times each.

I'd like to go to a local indoor race track and try to race but after being at a LRP competition this weekend as a spectator, I don't think my trusty TA02 would be much of a threat! I need to learn better control of the car as it is very fast with a GM 17 turn motor. After seeing the kind of cars that were racing there just blew my mind. All the kit they take to the race with them is just amazing and there was some wierd looking batts. I'm not ready for the world of single cell batts. This hobby really is full of 'black magic' mysteries!!

Many thanks, one peak detection charger coming up. Is there one that will charge more than one batt at a time?

Karl.

[raemin]

Many chargers do charge several batteries, but at a cost. You'd better go for several cheap chargers. Multiplex, graupner and a few other well known brands do offer high quality chargers for less than $50. The magic of Nimh is that they offer the best with very basic charging techniques (no need to cycle them, reflex charge them, etc..) so do not be misleaded with high ends chargers. The point is to leave them 1/3 charged when not in use as they have a high propensity to self discharge and really do not appreciate to be maintained to 0v for anything more than a few minutes.

A good thing to save your battery is to equalize them from time to time (i.e charge all cells to the same level), you can do this either by charging each cells separately or with a slow charge at 50mah.

[Live Steam Mad]

What brands / models of these battery pack chargers are there available that can "ZAP" the cells - raemain said "zapping, works both for NiCd and Nimh: the idea is to send a high voltage (30v to 90v) through each cells separately: this will break all the dendrite (also refered to as crystal) that are building up on the cathode"... this is why a lot of my old uniross AA NiCd 650mAh cells have died over the years since they have this "white powder" coming out of them which I assume is this crystal.

I would like to keep my 7.2 V packs in great condition and I would like a charger that can ZAP both NiCd and NiMH please.

Anyone know?

Cheers,

Alistair G.

[karlfrancis]

Hi Folks,

After looking around at different chargers, I've been giving great thought to getting a Swallow Advance from T2M. It's got a good rating and it's not too cheap. The spec on it says it can do a lot more than I'll ever need.

Has anyone had any dealings with this brand in the past? I don't think it does that 'zapping' thing though Live Steam Mad.

Kind regards,

Karl.

[karlfrancis]

I think raemin has had the best idea, that is buying a few cheaper chargers with peak detection. I'm only using stick style batts at the moment so I don't have the option of just changing a 'bad' cell.

Karl

[Live Steam Mad]

I know, dragging up old post here, but I recently found the answer to the question that I asked here.

The Duratrax Intellipeak ICE charger can do a reflex charge in NiCd and NiMH mode, which appears to ZAP the cells with a reverse spike for 0.4 per cent of the charge time (i.e. only for 4 milliseconds), whilst delivering normal linear forward charge 99.6 per cent of the time. This would appear to do the reconditioning function, especially on old NiCd packs that are starting to become 'tired' (lower capacity than expected).

See page 16 of their on-line manual ;-

http://www.duratrax.com/pdf/dtxp4170-manual.pdf

Of course I learned this *after* I just bought my MRC 969 charger last month. *Sigh*. 969 is awesome though, you can read a review of it and see pictures of it in my showroom entry for it.

Cheers,

Alistair G.