Can you over charge a NiCd igniter with a 125ma charger?

The mah in will equalize initially with the cell but at 125mah will push 100% capacity back to a given equilibrium at a percentage typically gradually drying out the cell over time reducing performance of Nickle Cadmium chemistry. Over time capacity is reduced directly proportional to voltage out. What would be best is about 30mah trickle charge once the cell is at full capacity at such a rate it only has enough to stop static discharging without compromising life span capacity. This leaves only degradation through normal duty without adding to it.

Thanks for the replies, and those are about what I expected the answers to be. Electronics is(was) actually my field, but that was a long time ago and I never worked with battery powered equipment much. I'll drain them when I can but won't worry so much about topping off occasionally. And I could always switch to NiMH too. I don't think it's much of an issue with those, and the same chargers work.
Rusty

I saw your post earlier and was gonna suggest nickel metal hydride battery upgrade if it was possible, I think its well worth the money.

RknRusty wrote:And I could always switch to NiMH too.Rusty

I wouldn't muck about with Ni batteries at all now-a-days.  Go straight for Li.  Far, far superior option.

One of mine has a replaceable sub-C battery, so I can buy a NiMH for that one. They only cost a couple of bucks.

RknRusty wrote:One of mine has a replaceable sub-C battery, so I can buy a NiMH for that one. They only cost a couple of bucks.

For those of us who run COX and other engines as well, a starter panel with adjustable current like the one pictured here, mounted on the  front of my starter/tool box is a very handy one.


Cox heads are known to best glow with 1,5 Volts DC while standard glow plugs run on 1,2 Volts DC or so. This starter panel provides intermittent 12Volts through its ignition sockets allowing you to set the average current at the desired level so that at 12V DC output it will not blow your plug.
This setup of mine (while apparently messy as I have just emptied it for the photo session)  is based on a 2000mAh 12VDC rechargeable battery that neatly sits in the right corner of the box, and can be charged through the sockets of the electric starter motor on the front panel. Space for other field gear is still avalable aplenty.

I have had so many frustrations with rechargeable batteries (especially not wanting to glow the head of Cox engines) and normal D type batteries that I decided to invest in this setup. This is powerful enough to drive even the large yellow starter motor as well, that I use for the OS Max 56 FS alpha engines. Lasts for many many days between recharges.

Yeah, I will probably get sophisticated some day. For now I just want to be sure when I raise my hand to start the 8 minute clock, at least one of the two igniters in my pocket works. It didn't take me long to figure out that for 1/2A the little igniters aren't very dependable because they'll die while we're flipping and cussing. I would like to have a plug-in box for shop running.
Rusty

There are some good points in this topic but they probably need summarising.

I use a starter panel powered by a motorcycle battery but it is heavy and I wouldn't fancy lugging it to the middle of a field.

Those little igniters are ideal for spark plug engines (not for Cox heads), the way they clip on and hold at any angle makes them convenient.

I have used NiCads since they were first introduced and there are two rules:-

1. Do not charge them at over 1/10 of their capacity. If you are charging at 125ma then the battery capacity must be 1250mah.
2. I have ruined countless NiCads by not discharging them before recharging. It doesn't happen straight away but they are prone to "memory effect". Keep only using 30% and you will find that, eventually, that is all you will be able to use.

I have replaced NiCads with NiMH batteries but this hasn't always been successful. I will list the advantages and disadvantages of both types but I have found that for any "power hungry" applications the NiMH is not a suitable replacement. They also self discharge quite quickly - much quicker than a NiCad. I have put freshly charged NiMHs in a torch and found that three weeks, later after very little use, they are flat. I now keep them in a variety of chargers on trickle charge.

The NiMhs are lighter than NiCads and have more capacity. It is a shame that they can't produce the same discharge.

As Roddie as indicated. You should invest in an intelligent charger so that you cannot overcharge but can charge much quicker as the intelligence senses what is happening to the battery. If you replace the NiCad in the igniter with NiMH and use the existing charger (if it a simple one like the one with my igniter) then you will probably undercharge. Usually 12-14 hours for a NiCad will (using the same charger) need 20 - 221/2 hours for NiMH because of the increased capacity.

You are unlikely to overcharge a NiCad at 1/10th charge but I wouldn't recommend leaving it charging over 14 hours. Overcharging with the subsequent disastrous results is usually a result of fast or rapid charging without monitoring.

Nickel metal hydride (NiMH) advantages:

lighter than NiCad
2-3X capacity to equal size NiCad

Nickel metal hydride (NiMH) disadvantages:

fewer life cycles compared to NiCad
shorter run time
performs the worst in cold temperatures
higher self-discharge level than NiCad
voltage drop at near-discharged levels

Nickel cadmium (NiCad) advantages:

longer life cycles
performs in cold temperatures (perform well to 20F)
lower self-discharge level than NiMH
no voltage drop at near discharged levels

Nickel cadmium (NiCad) disadvantages:

Heavy
May suffer from "Memory effect"

Thanks for the summary, Ian.
Rusty

I think that both NiCd and NiMh are wrong for this application. The will only give 1.2V on average during the disharge, or even lower if they are not dimensioned properly (they cannot be too small) to deliver around 2A. It sort of works for a short while on absolutely fully charged batteries, but that's about it...

The glow plug needs 1.5V so that immediately signals that one should use a regulator. The handheld Lipo drivers are pretty much optimal I think. Both in terms of battery technology (low self-discharge and very high discharge currents) and their stabilized voltage. In terms of size they are barely larger than the NiCd/NiMh ones either....

ian1954 wrote: I have put freshly charged NiMHs in a torch.....

Ian.
Watch your language. I spoke about using a "torch" over on 049 collectors and got myself in trouble, having to explain that if our American friends took a torch to their engines there could be a nasty fire. I wouldn't put a "torch" near my batteries either.

I think you mean "flashlight". Those with an MG or other British motorcar can probably safely keep a torch in the globebox without issue.

(Funny language, English!)

Rod.

Oldenginerod wrote:

ian1954 wrote: I have put freshly charged NiMHs in a torch.....

Ian.
Watch your language. I spoke about using a "torch" over on 049 collectors and got myself in trouble, having to explain that if our American friends took a torch to their engines there could be a nasty fire.  I wouldn't put a "torch" near my batteries either.

I think you mean "flashlight".  Those with an MG or other British motorcar can probably safely keep a torch in the globebox without issue.

(Funny language, English!)

Rod.

Try asking for a simple thing like a rubber in an office in the US and see what happens!

An eraser (US and Canada) or rubber (India, UK, Ireland, South Africa, Australia, New Zealand and Canada) is an article of stationery that is used for removing pencil markings. Erasers have a rubbery consistency and come in a variety of shapes, sizes and colours.

I recently came across these NiMH batteries, they are new to me and appear to be better than the old tech.
They claim to hold almost full charge for 1 year. Only 1.2 volt but are 2400 mAh.

I prefer the Eneloop brand..4 of its AAA size batteries comprise my 4,8 Volts  receiver battery pack in my R/C planes. They really hold full charge without any current drain for many months .

http://www.ebay.com/itm/16x-Panasonic-Eneloop-800mAh-AAA-1-2V-2100x-Rechargeable-Battery-BK-4MCCE-16pcs-/251471694566?pt=Batteries_Chargers&hash=item3a8ce18ae6

They could be all made by the same Jap

Yes, most probably...anyway it was the Enelooop brand of Sanyo that first hit the market with such long lasting voltage retaining feature some 3 or so years ago.