battery questions

[f1n3sse]

Hey guys, I just picked up a brand new MRC super brain 959. I called MRC and spoke to one of their techs and asked him about battery overcharge. He told me that by using the default settings the charge will automatically detect and adjust the millivolts but not the amps, it is default at 3.0 amps. My 1600mah hump pack is rated at 16hrs charge time at 1.0 amps, I charged it from completely discharged to fully charged in 20-25 minutes last night at 3.0 amps. He also told me that by using the 3.0 amp rate doesn't really affect sub-c cells. are these hump packs sub-c? also I know that my hump is 6 volts the charger displays over 7 volts at peak charge before trickle. is this normal and safe? I want to use the charger for all of my batteries including my glow ignitor. And if anyone owns the super brain MRC will send you out the glow starter adapter for free. you don't even have to pay shipping.

Thanks,
F1n

 

[Keithv]

I have a MRC 977.
You would have to look at the hump pack you are using to see what kind of cells it has but I would say its probably 2/3A cells. The sub c's are the size used in most igniters.
As for the charge rate. You can safely charge the pack at 3amps but the slower you charge a battery the better the charge will be. Charging the pack to fast creates a lot of heat which is bad for the cells. If you need to quick charge the pack once in a while thats fine but I would suggest to maximize the battery life, slow charge as often as possible.
The packs always show higher then their rated voltage on the chargers, its fine.
How did you get them to send you a glow starter adapter?

 

[Chris]

Hey guys, I just picked up a brand new MRC super brain 959. I called MRC and spoke to one of their techs and asked him about battery overcharge. He told me that by using the default settings the charge will automatically detect and adjust the millivolts but not the amps, it is default at 3.0 amps. My 1600mah hump pack is rated at 16hrs charge time at 1.0 amps, I charged it from completely discharged to fully charged in 20-25 minutes last night at 3.0 amps. He also told me that by using the 3.0 amp rate doesn't really affect sub-c cells. are these hump packs sub-c? also I know that my hump is 6 volts the charger displays over 7 volts at peak charge before trickle. is this normal and safe? I want to use the charger for all of my batteries including my glow ignitor. And if anyone owns the super brain MRC will send you out the glow starter adapter for free. you don't even have to pay shipping.

Thanks,
F1n

I owned a 989 and loved it...dunno about the 959 though.

What type of cell do you have NiCad or NiMH? How you charge and at what rates largely depends on the chemistry.

NiCad can be charged at much higher than cell ratings. NiMH doesn't need to be charged above cell rating in your case 1.6amps and that is where you want to be. I've found that a 6v Rx hump pack will do best charged at around 1.5amps. NiCad should be trickle charged and NiMH should not.

A 1500mAh pack will take (in a perfect world) 1 hour to charge at 1.5amps and this is called the 1C rating. This rating is equal to the cell rating. Pretty simple. There's no need to exceed this unless you are a serious racer and you're charging your main pack. This will seriously reduce pack life BTW.

Charge voltage will always be quite a bit higher than resting voltage. The Rx hump packs I build are 1500mAh (5 cell 6.0v) and will charge at 7.40v at peak and peak beyond 1500 mostly near 1600.

 

[f1n3sse]

I have a MRC 977.
You would have to look at the hump pack you are using to see what kind of cells it has but I would say its probably 2/3A cells. The sub c's are the size used in most igniters.
As for the charge rate. You can safely charge the pack at 3amps but the slower you charge a battery the better the charge will be. Charging the pack to fast creates a lot of heat which is bad for the cells. If you need to quick charge the pack once in a while thats fine but I would suggest to maximize the battery life, slow charge as often as possible.
The packs always show higher then their rated voltage on the chargers, its fine.
How did you get them to send you a glow starter adapter?

I read the owners manual that came with it. at the bottom of one of the pages it says there is a setting for charging single cell glow ignitors. It says call this number and MRC will send you out the adapter. Make sure you tell them you just bought one brand new and saw this in the owners manual. heres the number 732-225-6360

 

[f1n3sse]

I owned a 989 and loved it...dunno about the 959 though.

What type of cell do you have NiCad or NiMH? How you charge and at what rates largely depends on the chemistry.

NiCad can be charged at much higher than cell ratings. NiMH doesn't need to be charged above cell rating in your case 1.6amps and that is where you want to be. I've found that a 6v Rx hump pack will do best charged at around 1.5amps. NiCad should be trickle charged and NiMH should not.

A 1500mAh pack will take (in a perfect world) 1 hour to charge at 1.5amps and this is called the 1C rating. This rating is equal to the cell rating. Pretty simple. There's no need to exceed this unless you are a serious racer and you're charging your main pack. This will seriously reduce pack life BTW.

Charge voltage will always be quite a bit higher than resting voltage. The Rx hump packs I build are 1500mAh (5 cell 6.0v) and will charge at 7.40v at peak and peak beyond 1500 mostly near 1600.

Thats a lot of great info. since you are knowledgeable I have a 9.6v 8 cell pack for my tx do you have any idea how It should be charged for optimal performance and life?

 

[Chris]

Thats a lot of great info. since you are knowledgeable I have a 9.6v 8 cell pack for my tx do you have any idea how It should be charged for optimal performance and life?

That depends on the mAh rating of the pack. What is the mAh rating?

But I've found my own personal ratio (I build battery packs and do lots of testing). I charge all my 6-cell Rx packs at 1.5amps regardless of cell ratings (all the way up to 2700mAh for Rx my pack). What tends to happen much above 1.5amps for 5-cell 6.0v packs is that the charger will incorrectly detect peak or shut down from output over-voltage (exceeding healthy pack limits).

Now having said that you can still charge a 2700mAh 5-cell Rx pack at 2.7amps and do just fine. It will still charge as normal and have a long life. Charging above pack rating is where you start to lose life-span.

 

[f1n3sse]

i have a 2600 mah 8 cell pack and a 1850 mah 8 cell pack

 

[Chris]

i have a 2600 mah 8 cell pack and a 1850 mah 8 cell pack

2.4amps and 1.5amps will do you well. :jamout: