questions on my battery charger

[six4]

this is my battery charger.



has worked flawless for my on the other times i have used it,except for a couple nights ago. i go through the normal process of discharging using the discharge feature on my system, when the discharge is complete the machine lets you know so you can re-charge. here is the problem. the charger didnt stop when the battery was fully charged like it normaly does. i layed down for a bit and when i woke up and checked the charger,,it was at 4789m/h's :shock: the battery is only a 2400m/h. it was also so hot that i was scared to pick it up because the plastic sheath felt tacky and i was worried it would come apart. this is the damage from the heat of the overcharge.




the battery still works in the rifle,,the question i have is what kind of damage was done to the battery and why my only months old charger did what it did?

[Styrak]

Is it a digital peak detection charger?

[six4]

Originally Posted by Styrak

Is it a digital peak detection charger?

sorry,,im in the dark when it comes to anything electrical,,i would have better luck trying to drive a herd of cats than fix anything electrical, so i dont know what digital peak detection means. what i can tell you is that this charger has all kinds of bells and whistles,can charge,discharge,analyze,recondition,,does that help?

[Styrak]

Well then it's probably a peak detection charger. All that means is, it has logic to detect when the battery is full, and stops when it senses that. Maybe the logic chip got damaged, or some other part of the charger got fucked up?

It looks like pretty bad damage to the battery (looks like the cell got damaged/punctured?), and in that case, it would not be a good idea to use it, or even charge it again.

[six4]

Originally Posted by Styrak

Well then it's probably a peak detection charger. All that means is, it has logic to detect when the battery is full, and stops when it senses that. Maybe the logic chip got damaged, or some other part of the charger got fucked up?

It looks like pretty bad damage to the battery (looks like the cell got damaged/punctured?), and in that case, it would not be a good idea to use it, or even charge it again.

no, the cells are fine ,what's showing in the pic is the lead the connects the battery in its series,,the heat must have cracked the plastic a little but there are no punctures.

[mcguyver]

That little sensor you have resting on the top of your battery pack in the top picture is a temperature sensor, is it not? Funny it didn't kick the charger out when the battery got hot, unless it is adjustable and it was set too high. My charger has one of those sensors and I set it for 100F just to be on the safe side.

Peak detection means the charger is alwasy seeing feedback of the current it sends out to the battery during charging. When the current returning very nearly equals the current going out, the charger assumes that the battery is charged. During charging, the battery converts electrical energy from the charger into chemical energy stored in the electrolyte of the battery. The current required to do this declines as the battery becomes charged. At full charge, the current is nearly zero, but trying to insert too much current will lead to heating of the battery and damage to the electrolyte inside the battery. This is what causes damage.

It may also be that the excessive heating cause at the connection in the bottom picture may be the result of a poor solder connection. This will be a source of increased resistance, which leads to increased heat at that point. That may be what melted the heatshrink over the cells. At any rate, you would have to slice that open to check that connection point for damage, but only if your battery is not performing well. If your battery performs fine, leave it alone.

[six4]

Originally Posted by mcguyver

That little sensor you have resting on the top of your battery pack in the top picture is a temperature sensor, is it not? Funny it didn't kick the charger out when the battery got hot, unless it is adjustable and it was set too high. My charger has one of those sensors and I set it for 100F just to be on the safe side.

Peak detection means the charger is alwasy seeing feedback of the current it sends out to the battery during charging. When the current returning very nearly equals the current going out, the charger assumes that the battery is charged. During charging, the battery converts electrical energy from the charger into chemical energy stored in the electrolyte of the battery. The current required to do this declines as the battery becomes charged. At full charge, the current is nearly zero, but trying to insert too much current will lead to heating of the battery and damage to the electrolyte inside the battery. This is what causes damage.

It may also be that the excessive heating cause at the connection in the bottom picture may be the result of a poor solder connection. This will be a source of increased resistance, which leads to increased heat at that point. That may be what melted the heatshrink over the cells. At any rate, you would have to slice that open to check that connection point for damage, but only if your battery is not performing well. If your battery performs fine, leave it alone.

yes the heat sensor is a little magnet that sits on the battery. the setting is non adjustable as far as the manual goes. it seems to fire just fine,but i will be taking the charger back to where i bought it to see if it can be tested out. thanks for the input.

[ILLusion]

Based on the product number I pulled off the image of your charger, I googled it and came up with this:

http://www.nimhbattery.com/mh-c777plus.htm

Maybe you'll find something useful on that page that may help you with operation.

I've used Maha products in the past, and generally found them to be good products.