Battery/Charger advice wanted please

[Azarken]

Hi all

I got into airsoft over 5 to 6 years ago now and have taken various breaks and am back again. Back when i first started I bought a Ripmax Propeak 2500 charger (the non varipulse version). It seemed to be recommended by most stores back then and despite the ever running argument of fast vs slow charging the general consensus seemed to be the first time you get a battery slow charge it and use it then after that a fast charge should be fine because its run in. These advice seemed to pan out because my larges and minis that are over 3 years old seem to still work fine and hold a decent charge. With the charger you simply hit the fast charge button, it works out when the battery is full, and then beeps at you and switches to trickle charge. Occasionally the batteries were warm but never hot and never melting down.

Now, I have a gun arriving thats required me to buy a battery pack different to my usual larges and minis. So off I went to a well known online battery shop and ordered two. Hrmm I thought I wonder if theres any new thoughts on how to charge them so I emailed the shop to ask the best way of charging them, and they said

The Optimum charge rate for any NiMH battery is 10% of it's total capacity, so in the case of a 1600mA battery this would be 160mA. NiMH batteries will always benefit from a slow charge as this allows all cells to reach maximum capacity without any of them overheating from overcharging. A reasonable rate to charge them at is about 400mA. We've found that this causes the batteries no harm at all and their life span is pretty much unaffected. Of Course, you can charge them at 1600mA capacity if you wish, although this is not recommended until the batteries have been fully run in. And whilst the batteries will take this fast charge, ultimately it will reduce their battery life. Where a set of batteries charged slowly ever time may last a couple of years, a set that has been fast charged each time are likely to give out in 6 months or less.

Hrmm OK I thought lets look at my pro peak 2500 and see its rate. 130mah for trickle charge and 3.4ah for a fast charge. That seemed way to high so I emailed them back and got this reply.

at 130mA a 1600mAh battery would take about 17 hours to charge. The 3.4A setting is far to aggressive for a 1600mAh battery. I'm actually extremely surprised that a 1600mAh battery would last a few years being charged at that rate, as most we have seen charged at more then 3A have been boiled within 30 minutes.

Now admittedly most of my previous batteries were large 3000-4300 ones but I do have some minis too and they seem no worse off for me fast charging so I was wondering.

1. Is it still considered best practice to trickle charge first time then fast charge after that?
2. Is my pro peak charger actually not putting out 3.4Ah but instead being clever and lowering its rate to match the battery?
3. If the answer to 2 is no and it is actually putting 3.4Ah out, is that safe, and thus the info above from the battery place wrong?
4. Or is the info right and I should just go buy another more adjustable charger?

I find it hard to believe such a widely sold airsoft charger would have a fast charge feature thats dangerous and damaging to the batteries, plus the fact I've fast charged my batteries tons of times on it and never had a issue. I guess I could have been lucky but seems unlikely.

All info gratefully received.

Az

[MisterX]

Re: Battery/Charger advice wanted please

Hi all

1. Is it still considered best practice to trickle charge first time then fast charge after that?
2. Is my pro peak charger actually not putting out 3.4Ah but instead being clever and lowering its rate to match the battery?
3. If the answer to 2 is no and it is actually putting 3.4Ah out, is that safe, and thus the info above from the battery place wrong?
4. Or is the info right and I should just go buy another more adjustable charger?

I find it hard to believe such a widely sold airsoft charger would have a fast charge feature thats dangerous and damaging to the batteries, plus the fact I've fast charged my batteries tons of times on it and never had a issue. I guess I could have been lucky but seems unlikely.

All info gratefully received.

Az

C - Battery Capacity (1600mah/1.6a)

1. In the battery industry it is considered to do what is called a forming charge first charge round. (Charge to full at half C, Discharge at half C then charging to full at a rate of 0.1a). However that is only with the defunct NiCAD cells and NiMH cells. It is still good practice but not essential. (I form all my batteries, all going strong and some are 7 year old NiMHs.

2. The Ripmax Pro Peak 2500 if I remember correctly was pre micro processor controlled therefore will not switch to trickle charge.

3. Charging a 1600mah battery at 3.4a (3400mah) is charging at 2c. It will heat up considerably but shouldn't burst into flames, however depending on the wiring rating; the wire may heat up and burn a bit, the life expectancy of the pack will dramatically reduce over time. It has the potential to be dangerous.

4. I would recommend you get a modern day programmable smart charger, I personally recommend the Imax B6 or the GT Power A6 available from ebay. The GT comes with a temperature cut off and includes a sensor - very useful for lipos.

Personally I charge my 1600mah packs at 0.5a for normal charging (Charge time roughly 3 hours) and at capacity for fast charging so 1.6a (1 hour). Basically I charge all of batteries the night before, I've got a fair bit of battery equipment so I can charge up to 8 packs at one time.


Also the Pro Peak 2500 was never designed for Airsoft, it was designed by Ripmax for use with RC Model cars and aeroplanes, where packs were anything from 700mah to 8000mah, thus the higher charge rates found on ripmax chargers. This is what the fast charge was designed for as in RC car racing packs are fast charged at high rate and changed in pit times normally soldered directly to the input wires for maximum output no switches or fuses used (every switch or connection looses power). Ripmax is a major distributor of RC products in the UK, they did bring one of the programmable chargers to the UK market many years ago called the Supernova, it was very popular however was not micro processor controlled.

Cheers

Source, I used to be a battery manufacturer specialist

[Stealthkiller]

Re: Battery/Charger advice wanted please

A good recomendation from me is the jp pro multi format chargers . They will charge any battery you can find and then some . Charge rate up to 50 amps .
Built in mains power supply as well as the usual 12/18 volt input for power
Can charge , nimh , nicad , gel cells , lipo , life , life+ , acid cell ( car battery's ) and more
Has USB output for linking to a computer as well as a heat sensor probe input ( not supplied )
This is an rc spec charger from the renowned jp group . I got mine for just under 45 quid with a warranty included ..

[Azarken]

Re: Battery/Charger advice wanted please

thanks guys have since switched out to lipos due to new gun having very small battery space got a nice smart charger and all the better for it

[MisterX]

Re: Battery/Charger advice wanted please

Good stuff mate if you need more help just post back here or give me a pm gladly help

Cheers

[Azarken]

Re: Battery/Charger advice wanted please

thanks

[Stealthkiller]

Re: Battery/Charger advice wanted please

If you are storing a lipo for a long periods leave them 50 per cent charged as a full charge will oxidise them and reduce cell life .