Charger/ cell Ideas?

[ralphee]

Hey guys

OK ive been out for a long time and so much has moved on.
I need a good charger, but dont want to break the bank too much!
Looking at spending around the £70 mark on something that may charge, discharge and maybe balance?
Id seen a 601BC unit on ebay and wondered if this would be any good?
Its a lot different to the Millenium i used to have though.
If not, can anyone point me in the right direction, id like something AC/DC if poss.
Also, cells, what a safe bet to buy for racing nowadays, ive read the poss rule changes but i could do with a few packs to get me rolling, so 3700's maybe?

lee

[ralphee]

Just to clear up, the chargers ive looked at are by Imax, just wondered if anybody uses them, or if there cheap junk lol.

lee

[ralphee]

So, nobody looking at this post uses a charger or can recommend one in my budget?

lee

[Martin-Barbour]

I've been using the Pro-Peak Sigma AC/DC charger for about 7 months now.
It's not one of those large yellow faced jobbies, it's a slime line Blue / fake carbon fibre case with a digital readout, will charge and discharge Ni-Mh, NiCad, Lead Acid and Lipo batteries.
I believe it has a balancing connection for Lipos although the required cable is not included.

There's very little you can edit for the charge / discharge profiles but if you're not intending to look after any of the newer Hi-Spec cells then it's worked fine for me with older GP33000s and GP3700's so far.

I think it was about £75 new.

No doubt others will have other opinions but it's a start....

[drinternat]

I got a Pulsar 3 (new) on Ebay for about £75. From RC Mart (Dinbal) I think it was.

[Eddie168]

I am using a Orion Advantage carbon edition charger and i ahve to say this is one onf the best charger you could get on the market

here is the link: http://www.teamorion.com/Products/Ch...+_+Dischargers

[unluckypixie]

Originally Posted by Eddie168

I am using a Orion Advantage carbon edition charger and i ahve to say this is one onf the best charger you could get on the market

here is the link: http://www.teamorion.com/Products/Ch...+_+Dischargers

Ditto. I've got one and it's just brilliant, it even has a magnetic thermometer to attach to packs when charging! The menus are a little confusing but I'm getting used to it, after about a month I've only just worked out how to set the cutout temperature (I was convinced it wasn't possible til I pressed the "wrong" button one day!)

I particularly like the fact that I can do charging/discharging and cycling on single cells! - So I can check out their performance before soldering into packs! It also has stepped charging, i.e. 5.5amp up to 2000mah then 4.5amp up to 3000mah then topup at 3.5amp or "megaflex" charging whereby it does short pulsed discharges while charging which apparently removes bubbles of gas in the battery caused by the charging process.

My only complaint is that I would like the alarm when it completes, but to have the alarm on you have to have it beep whenever you press a key and that is really grating!

[Eddie168]

Originally Posted by unluckypixie

Ditto. I've got one and it's just brilliant, it even has a magnetic thermometer to attach to packs when charging! The menus are a little confusing but I'm getting used to it, after about a month I've only just worked out how to set the cutout temperature (I was convinced it wasn't possible til I pressed the "wrong" button one day!)

I particularly like the fact that I can do charging/discharging and cycling on single cells! - So I can check out their performance before soldering into packs! It also has stepped charging, i.e. 5.5amp up to 2000mah then 4.5amp up to 3000mah then topup at 3.5amp or "megaflex" charging whereby it does short pulsed discharges while charging which apparently removes bubbles of gas in the battery caused by the charging process.

My only complaint is that I would like the alarm when it completes, but to have the alarm on you have to have it beep whenever you press a key and that is really grating!

Yea it is a brilliant charger but i am not quite understand what's different between those different charge mode like mega flex, step charge bla bla bla, cause i normally use normal charging mode and i am not sure what is peak sensitivity is any idea? and yea the beep noise is so annoying that's why i turn it off as well

[super__dan]

Originally Posted by unluckypixie

The menus are a little confusing but I'm getting used to it, after about a month I've only just worked out how to set the cutout temperature (I was convinced it wasn't possible til I pressed the "wrong" button one day!)

How, I've not yet managed that?

I have a pulsar and Orion, and prefer the Pulsar. But to be honest, neither are RRP < £75

[unluckypixie]

Originally Posted by Eddie168

Yea it is a brilliant charger but i am not quite understand what's different between those different charge mode like mega flex, step charge bla bla bla, cause i normally use normal charging mode and i am not sure what is peak sensitivity is any idea? and yea the beep noise is so annoying that's why i turn it off as well

Here is my understanding of the charge modes (this might not be 100% correct please correct me anyone...):

Megaflex: By discharging the battery briefly during periods of charging the "megaflex" mode frees gas bubbles that build up in the battery these gas bubbles build up on the internal contacts and increase the resistance so by removing them you decrease the resistance making the battery charge better and not get as hot while charging - in short it's supposed to be a brilliant thing and you should use it if you have it! - Incidentally a friend of mine told me that he thought megaflex was only for NiCad and not for NiMH cells, but I have my charger set to NiMH and it still has the option so I'm assuming it's ok for them...

Stepped Charging: The reason for the stepped charging is that if you have got say 3700mah cells you are supposed to charge them at a maximum of 3.7Amps (for 3300 it would be 3.3A or 4200 it would be 4.2A), at that or under that you should get a good charge into them and they should last reasonably when you use them. However if you charge them higher than that then the batteries will be more "punchy" but will not have as long duration (this is ok because 3700 have more than enough for one round anyway). The higher you go the punchier performance you get, however also the higher you go the more likely the battery is to explode while you are charging it!

"peak sensitivity": basically a 3700mah cell can only hold 3700mah of power, once it has stored as much as it can (which in reality will be slightly less than 3700) further charging on the cell instead of increasing the voltage simply causes heat and actually a slight decrease of the voltage. By looking for this decrease the charger can tell when the battery is actually full or "peaked" the amount of decrease before the cell is considered to have peaked is the "peak sensitivity" - if you have this too low, then your charger might get a "false positive" reading (if the voltage drops due to gas buildup or some other reason during charging) and stop charging before the cell is full but if you have it too high then the charger will not realise when the cell is full and will keep charging it and this may actually cause the cell to explode! The step charging allows you to use the dangerous really high speed charging for the initial period of the charge but then reduce down to a sensible charging speed at a point when you think the battery is nearing it's maximum charge, i.e. charge at 5.5A for 2000Mah then 3.7A for the next 1700Mah. The problem with peak sensitivity is that it's measuring the whole pack, so if it's say 5mv per cell what it's actually looking for is a 5*6=30mv drop across the whole pack before assuming it's complete. The problem is that if you don't have matched cells and 1 is charged but the other 5 are not that one might be getting dangerously overcharged. For that reason the orion automatically cuts off when it reaches the capacity you have specified, i.e. 3700mah irrespective of whether the peak has been detected or not. This is why some people actually set their orions to a little extra, say 3900mah to make sure that the cells actually peak (but this is a little dangerous!).

[unluckypixie]

Originally Posted by super__dan

How, I've not yet managed that?

I have a pulsar and Orion, and prefer the Pulsar. But to be honest, neither are RRP < £75

Mine was! - It was second hand off ebay and good as new! ...

You probably like me assumed that all the settings were on the battery setups, but for some reason they are not. On the mode where up and down cycle through "cycle", "discharge", "charge" etc... go to "charge" and click "setup" then click down and it will show you the charge rate (which you set on the battery setup anyway) but pressing down some more will show you lots of cool options! Including the megaflex duration (1-20ms I think) the set temperature, the number of repeaks (I assume this is a way of stopping false positives on peak detection) and trickle on or off, which is once the cell is charged if it trickle charges it to keep it peaked until you actually remove if from the charger.

I don't know for definate but I am assuming that the "set temperature" set on the charge menu would also be used if cycling or discharging? I might have to test this by putting the thermometer on something hot while it's cycling/discharging.

The menu system is a little confusing to me but this charger is just amazing with all the features it has and with the temperature sensor and all the other checks it makes me feel safe that it's not going to blow up my cells!