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Charging Lithium Battery

ronsimpson

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Thread starter #1
I have a drill and battery with no charger.
upload_2018-3-30_16-7-10.jpeg
LBXR1512 from Black & Decker
"12V Lithium" 18W 1.5Ah "10V under load"
What does "Type 5" mean?
A partly charged batter measures 11.66V with no load.
I don't know if it is 4 cells of 2.9V each or 3 cells at 3.88V.
It might be 4 cells and I should charge to 4.1x4=16.4V.
It might be 3 cells and I should charge to 4.1x3=12.3V.
I think charging at 0.5A should be very safe.

Question: How would you charge it?

Graph form battery university .com
upload_2018-3-30_16-20-51.jpeg
 
#2
That would be a 3 cell pack. Best is to get a charger designed for this pack as it most likely would monitor intercell voltage. If you must, charge to 12.3 volts at no more than 0.5 amp (preferably lower) then hold at 12.3 volts until the current falls to 100 mA or so.. That should give you 80% charge.
 

Pommie

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#3
The word Lithium doesn't really tell you the cell chemistry. LiFePO4 could be a possible candidate in which case it would have 4 cells 0f 3.2V - LiPo (unlikely) would be 3 at 4.2V. Can you open it and see how many cells there are?

Mike.
 

ronsimpson

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Thread starter #4
Best is to get a charger designed for this pack
There were only a small number made. I think. There are many 20V batteries. I can get the 20V charger but I have not found the 12V. Some people say the 12 and 20 use the same charger but the writing on the box does not say so.

B&D made male or female batteries. (sex of the connector) I can get the wrong sex easy. (Probably also wrong battery type)
I found a charger that might work on most B&D batteries but it cost more than a new drill + battery + charger.

Can you open it and see how many cells there are?
I think I can. Hex screws.
I believe that there is not a way to know what the voltage limit should be. (with out knowing the chemistry) V=3.6 to 4.2 depending on chemistry.
It appears a wrong voltage limit and it will not hold much power or it will die very soon. That gives me an idea. I should count cells. Build a charger with a voltage limit that is too low. Discharge and count AmpHours. Which should be a little less than 1.5Ah. Increase the voltage limit and charge again and count the discharge time. If I get 1.0AH of storage then I am getting close.
---edited----
Special hex screws that do not work with a normal hex wrench.
 
Last edited:

ronsimpson

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Thread starter #7
Ylli,
Thanks for the links. I can not get a picture of the other side of the charger. (looked for weeks) So far all the B&D chargers I can get pictures of show the wrong sex of connector. (or don't show the under side)

This is not what I have. I have the reverse where the charger has the metal blades sticking out and the battery has female parts that are covered up where you can't see them. I need the reverse of this:

upload_2018-3-31_11-40-17.jpeg
 

ronsimpson

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Most Helpful Member
Thread starter #10
Thanks.
I think I will get one of the $15 slow chargers. Not the $60 fast charger. I can get the drill + battery + charger for $29 (old model clearance). Or I can through away the drill+battery when it runs down.

It just bugs me that some of the chargers say 12/20V in the title while the "wall wort" part says to be used with 20V batteries only. The chargers in the store say 20V only and look just like the 12/20 chargers. How 12/20 when the battery data sheet says a 0.1V error in voltage will shorten the battery life?

$15 is not too much to invest in a small drill.
 

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