Airsoft Canada - View Single Post

Mafioso_Grande · July 9th, 2006, 23:15

I'm a crazy guy who races RC cars and plays airsoft, so maybe I can help you out. I've been through a bunch of chargers and have a decent understanding of batteries. The following explanation covers 2 things: my guess at what the numbers on your charger mean, and how to actually find out the capacity of your batteries. Just keep in mind this explanation of your charger is being put together from pictures of your charger and online info, I don’t have any first hand experience with this charger.

I've looked into your charger online (TLP 4000C IntelliCharger), and every article/sales site I can find of it says it has peak detection, so it should be able to auto detect when you batteries are charged, then switch from fast charge to trickle charge mode. Just wait for the charger to beep.

So now your probably wondering what the different mAh (milliamp-hours) ratings on the knob are for… I have never seen that on any charger before in my life (airsoft is really funky when it comes to batteries), so here’s my (somewhat

) educated guess:

Almost all peak chargers can adjust the input current into the batteries they’re charging, most range from 0.5 A to about 7 A. This is done to decrease charge times, because sitting around while batteries charge sucks. The problem is that you can’t charge small capacity batteries at really high rates, the cells of the battery will overheat and you’ll toast your battery pack, so you need an idea of the capacity of the battery pack in order to determine the MAXIMUM charge rate for that pack (you can always charge packs at a rate lower than the maximum).

Now look at the knob on your charger, it has 2 sets of numbers. There’s a 1, 1.5, 2, 2.5, 3, 3.5, 4, I’m confident this first set of numbers is the charge rate (current, in Amps). The second set is under the first and is a bunch of mAh capacity values. It seems the second set of numbers are the smallest battery capacity recommended for charging at the above rate, so if you want to charge a 1700 mAh = 1.7 Ah battery, the people that made this charger don’t recommend you charge it at a rate higher than 3.5 Amps.

Since you’re unsure of the capacity of your batteries, just charge them at a low rate, maybe 1A, and you should be safe. NOTE: since your dealing with smaller batteries made of 2/3A and AA cells, I suggest you charge them at really low rates. These cells are far less rugged than the sub C cells used in large battery packs. I wouldn’t advise going above 2 A, regardless of what capacity we determine your batteries to be.

Okay, now we can determine the capacity of your batteries. The best we can do is get an estimate, but since you’re only interested in capacity for charging purposes, an estimate should be good enough. If you believe what I just typed about charge rate, all you need to do is time how long it takes for your battery to charge (in hours) at a known rate (in amps). You then multiply the time it took for the battery to charge by the charge rate to get the battery’s capacity. So we have:

Capacity (Amp-hours) = Charge rate (Amps) x Charge time(Hours)

Lets say you charge a battery at 1A, and it takes 35 minutes (or 0.58 hours). The capacity of this battery is

1A x 0.58 hours = 0.58 Ah = 580 mAh, this could be a standard NiCd small battery.

I hope this clears things up. There are other more accurate methods of determining a battery’s capacity, but this should be good enough. Just beware of false peaks coming from your charger (these happen every so often with peak chargers). To avoid these you can try to re-peak the batteries shortly after their first peak, but I’m not sure if this is a good idea given the cell types in your batteries.

July 9th, 2006, 23:15	#20
Mafioso_Grande Trader rating Join Date: Dec 2001 Location: Vancouver, BC	I'm a crazy guy who races RC cars and plays airsoft, so maybe I can help you out. I've been through a bunch of chargers and have a decent understanding of batteries. The following explanation covers 2 things: my guess at what the numbers on your charger mean, and how to actually find out the capacity of your batteries. Just keep in mind this explanation of your charger is being put together from pictures of your charger and online info, I don’t have any first hand experience with this charger. I've looked into your charger online (TLP 4000C IntelliCharger), and every article/sales site I can find of it says it has peak detection, so it should be able to auto detect when you batteries are charged, then switch from fast charge to trickle charge mode. Just wait for the charger to beep. So now your probably wondering what the different mAh (milliamp-hours) ratings on the knob are for… I have never seen that on any charger before in my life (airsoft is really funky when it comes to batteries), so here’s my (somewhat ) educated guess: Almost all peak chargers can adjust the input current into the batteries they’re charging, most range from 0.5 A to about 7 A. This is done to decrease charge times, because sitting around while batteries charge sucks. The problem is that you can’t charge small capacity batteries at really high rates, the cells of the battery will overheat and you’ll toast your battery pack, so you need an idea of the capacity of the battery pack in order to determine the MAXIMUM charge rate for that pack (you can always charge packs at a rate lower than the maximum). Now look at the knob on your charger, it has 2 sets of numbers. There’s a 1, 1.5, 2, 2.5, 3, 3.5, 4, I’m confident this first set of numbers is the charge rate (current, in Amps). The second set is under the first and is a bunch of mAh capacity values. It seems the second set of numbers are the smallest battery capacity recommended for charging at the above rate, so if you want to charge a 1700 mAh = 1.7 Ah battery, the people that made this charger don’t recommend you charge it at a rate higher than 3.5 Amps. Since you’re unsure of the capacity of your batteries, just charge them at a low rate, maybe 1A, and you should be safe. NOTE: since your dealing with smaller batteries made of 2/3A and AA cells, I suggest you charge them at really low rates. These cells are far less rugged than the sub C cells used in large battery packs. I wouldn’t advise going above 2 A, regardless of what capacity we determine your batteries to be. Okay, now we can determine the capacity of your batteries. The best we can do is get an estimate, but since you’re only interested in capacity for charging purposes, an estimate should be good enough. If you believe what I just typed about charge rate, all you need to do is time how long it takes for your battery to charge (in hours) at a known rate (in amps). You then multiply the time it took for the battery to charge by the charge rate to get the battery’s capacity. So we have: Capacity (Amp-hours) = Charge rate (Amps) x Charge time(Hours) Lets say you charge a battery at 1A, and it takes 35 minutes (or 0.58 hours). The capacity of this battery is 1A x 0.58 hours = 0.58 Ah = 580 mAh, this could be a standard NiCd small battery. I hope this clears things up. There are other more accurate methods of determining a battery’s capacity, but this should be good enough. Just beware of false peaks coming from your charger (these happen every so often with peak chargers). To avoid these you can try to re-peak the batteries shortly after their first peak, but I’m not sure if this is a good idea given the cell types in your batteries.