Blown My Charger

[jack0987]

Yep. I blew it. Connected my battery to the on board connector instead of of my reverse polarity connector on the right.

Is there anything I might do to prevent this in the future or perhaps I could buy a different charger.

 

[Diver300]

Normally you would try to make sure the connectors are physically different. If the ones on the board aren't used, remove them or fill them with silicone sealant.

 

[jack0987]

Normally you would try to make sure the connectors are physically different. If the ones on the board aren't used, remove them or fill them with silicone sealant.

Thanks.

They are JST connectors, and there seems to be no standard as to their polarity. Perhaps the addition of some kind of wrong polarity protection might do.

I wonder if a couple of diodes on the negative terminal would offer some protection.

In any event, I need to replace it with something or the same thing.
If you know of anything, please suggest.

 

[rjenkinsgb]

I'd change all connectors to one standard, polarised type - eg. XC30 for something small like that.

If you cannot change the connection on whatever the battery is used with, use a short JST cable to an XC30 plug and leave that connected to the device.

(You cannot add diodes without messing up the charge voltage, on a fixed voltage charger. It would need an electronic sense circuit and relay, or something similar).

 

[jack0987]

I'd change all connectors to one standard, polarised type - eg. XC30 for something small like that.

If you cannot change the connection on whatever the battery is used with, use a short JST cable to an XC30 plug and leave that connected to the device.

(You cannot add diodes without messing up the charge voltage, on a fixed voltage charger. It would need an electronic sense circuit and relay, or something similar).

Thanks. Since for right now and all of my batteries are the same polarity, when I get my new charger, I will tape off the system board sockets.

 

[BobFadiOfficial]

Yes try a different charger. This would be good for you and hopefully work.

 

[jack0987]

Yes try a different charger. This would be good for you and hopefully work.

Actually, I may go to using button top batteries since they are polarized and get a charger for them.

I see them at various mA hours. With the 18650 type, most are at about 3200 mAh but one is at about 9000 mAh. That is quite a difference.

Are the numbers real?

 

[Nigel Goodwin]

Actually, I may go to using button top batteries since they are polarized and get a charger for them.

I see them at various mA hours. With the 18650 type, most are at about 3200 mAh but one is at about 9000 mAh. That is quite a difference.

Are the numbers real?

No, the 3200 one 'may' be fairly close, but usually they are about 2600 for that size of battery - certainly the branded Samsung ones we buy at work are only 2600 mAh.

I've got some at home that are listed as 4000 mAh - although I'm dubious about that claim, but they are probably higher than 2600 mAh - as they are physically slightly larger than 18650's (so won't fit in 18650 battery holders, or anywhere that space is tight).

 

[jack0987]

No, the 3200 one 'may' be fairly close, but usually they are about 2600 for that size of battery - certainly the branded Samsung ones we buy at work are only 2600 mAh.

I've got some at home that are listed as 4000 mAh - although I'm dubious about that claim, but they are probably higher than 2600 mAh - as they are physically slightly larger than 18650's (so won't fit in 18650 battery holders, or anywhere that space is tight).

Got it. Thanks so much.

 

[danadak]

I'd change all connectors to one standard, polarised type - eg. XC30 for something small like that.

If you cannot change the connection on whatever the battery is used with, use a short JST cable to an XC30 plug and leave that connected to the device.

(You cannot add diodes without messing up the charge voltage, on a fixed voltage charger. It would need an electronic sense circuit and relay, or something similar).

If you could find the charge sense line and connect it downstream of a
polarity protection diode that might work.


Regards, Dana.

 

[tepalia02]

I think it will be wise to add something like this to your next design for reverse polarity protection.

For more info about zener diodes you can see here: https://www.theengineeringprojects.com/2019/09/what-is-the-zener-diode.html

 

[Lax Luthier]

I'd change all connectors to one standard, polarised type - eg. XC30 for something small like that.

If you cannot change the connection on whatever the battery is used with, use a short JST cable to an XC30 plug and leave that connected to the device.

(You cannot add diodes without messing up the charge voltage, on a fixed voltage charger. It would need an electronic sense circuit and relay, or something similar).

You could protect the circuitry with a diode connected reverse polarity from the + conductor to to ground, and a fuse in series with the + connector. A reverse polarity input would blow the fuse (which needs to be sized for current and speed). Shouldn't be too difficult to calculate.