Charging questions
 

I've got a Mtroniks J4 peak delta charger. It has a switch that selects either 1A, 2A or 4A.

I have 4 batteries (stick packs) 2x 3600, 1x4000 and 1x4500 mAh.

I understand that you're supposed to charge your batteries at 1C which is fine for the 4000mAh battery because I can use the 4A switch.

But what about the other batteries? I've been charging them all at 4A. Is this correct? I've noticed that it takes a good few hours to charge, even the 3600's take about 2 hours at 4A.

Should I be charging them at a different rate? Shouldn't a 4000mAh take about 1 hour at 4A?

Have I been buggering up my batteries? :(

is your charger a pulse charger, not good for nimh batteries im afraid on a linear charger 4a is fine
hope this helps

im using a nosram stealth charger set to 4.5amp and its lowest rolover setting, are are taking 90mins from flat/equalised

how would I know if it was a pulse or linear? It's a Delta peak charger http://www.mtroniks.net/news.asp (Top of the page)

As far as I know it's designed for nimh and nicad batteries.

What mAh batteries are you charging @ 4.5amp?

This one?

http://www.midlandmodelcentre.co.uk/...s/large/j4.jpg

4 amps will be fine for all. Your only just over for the 3600's

Are you using it plugged into the 249v mains? That will explain the time to charge your 36's. It's 1.2amps if plugged into mains

Can you sellect NiCd or NiMh?

If you can set it to NiMh

Specs for charger are quoted as @ Midland Model Centre

J4 Fast Delta Peak RC Battery Charger AC/DC NiCd NiMh.

This Delta peak quick charger can be run from mains or DC (croc clips). Its small size make it a very convenient piece of equipment to have, varaible amps 1,2 or 4

Some specs below
Double AC/DC input
AC : Charges 4-8 cells @ 1.2A
DC : Charges 4-7 cells @ 1.2A or 4A
Controlled by an 8bit CPU
LED and audible indicators
Re-peak function
Polarity & short circuit protection

its only a budget charger and delta peaks are normally pulse chargers im sure someone will correct me if im wrong:p

To find out get a fan from maplins and stick it in, if its constant its a constant charger if it pulses then its a pulse charger :P

normally, how long should it take to charge a discharged (ran in the car until it stops) 3600mAh @ 4A? I would have thought it should take about 45 mins?

Mine takes a couple of hours... :\ That right?

but the charger clearly says it charges both nimh and nicad. So are you saying that if it is a pulse charger it might be damaging my batteries?

ninj never let them discarge in the car mate, as soon as the power drops you should turn the car off as running them flat will ruin them, my 4200 take about an hour to charge

If your using the charger from the 240v mains it only charges @ 1.2a according to the specs. That's why it's taking a lot longer to charge.

Yes because its running off mains so its only actually charging at 1.2A, you only get the full 4A charge rate when running off 12v DC.

Edit: Glenn beat me to it ^^^ :p

Ahh! That makes sense!

So To get it charging quicker I need to plug it into a car battery or something?

Can you get chargers that charge at 4Amps from the mains and 12V?

Dont know, my sigma was meant to charge at 5A but when i plugged it into my 12v power supply and measured it, it was only draining 3A :confused: pretty much all of the chargers are 12v only really.

Now I'm really confused! :eh?:

So, forgive my noob-ness on this issue, but if you have a 12v charger, you then need some sort of power supply that plugs into the mains?

Can you not get a charger that has it's own 12v supply built in that isn't a pulse charger and will be able to charge at 1-4 amps? If it also made tea that would be a bonus!

Sorry about that lol.

Pro Peak make a charger thats 240v/12v, it states to hav a max charge rate of 5A running off both 240v and 12v yet when i plugged it into the power supply it only drew 3A so im thinking it only took 3A from the socket on 240v and didnt actually do 5A. For 12v chargers you get a supple that plugs into the mains and converts it to around 12v DC, yes.

Yes you need to plug it onto a car or "caravan type" battery, or a 12volt power supply or a generator, it wont pull 4 amps off the mains.

Yes you can get chargers that charge at 4amps off the mains and 12 volts, we use a BC6 - charges upto 5amps, cost a lot more.

Most racers use 12volts and keep a leisure battery just for charging car batteries. There has been a history of charging at well over 1C and a history of cells failing/cooking/exploding, that is why 1C is now recomended, your batteries may last longer if charged at the lower settings.

You will find very few racers using stick packs, single cells soldered into side by side six packs or three + three or four + two is the norm, these packs may have been hand picked to charge/discharge in sync.

Your charger may pulse charge, it will charge your NiMh batteries, but may not do them any good in the long run. Most of us want a linear charger that we can adjust the delta peak on.

When you think that matched batteries may cost £50 a pack plus, a better charger is a must. hope this is helpful, we all started with stick packs and simple chargers.

Ok, so what difference does it make whether you have 6 cell saddle pack, or 6 cell stick?

Are cells not cells however the layout is configured? i.e. How would I benefit from running a saddlepack arranged end to end rather than a stick?

I swear this RC lark has got more complicated since the 80s :p :lol:

Cheers!

There is no difference in the cells in any configuration, like you say the cells dont change, but only the weight distribution depending on the layout of your car.