I have a florabest hedge trimmer. When trying to charge the battery it starts off red and after a few minutes it starts to flash green and red. Is the battery dead?

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On 29/11/2020 15:15, Andrew Middleton wrote:
I have a florabest hedge trimmer. When trying to charge the battery it
starts off red and after a few minutes it starts to flash green and red.
Is the battery dead?

That's typically a sign that the charger has decided not to continue.
What type of battery is it?

In article rect.com,
Andrew Middleton wrote:
I have a florabest hedge trimmer. When trying to charge the battery it
starts off red and after a few minutes it starts to flash green and red.
Is the battery dead?

That is normally some form of cell equalisation. Does the display
eventually change to something else?

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*Frankly, scallop, I don't give a clam

Dave Plowman London SW
To e-mail, change noise into sound.

Dave Plowman (News) wrote:
In article rect.com,
Andrew Middleton wrote:
I have a florabest hedge trimmer. When trying to charge the battery it
starts off red and after a few minutes it starts to flash green and red.
Is the battery dead?

That is normally some form of cell equalisation. Does the display
eventually change to something else?


This isn't the device in question. It'a a Florabest 40V pack and charger.
It's Lithium and Samsung cells. The pack is equipped with a fuse.

https://www.youtube.com/watch?v=hMMW3v5da4s

Reading the chip number off the 20 pin TSOP, and looking
up that part and its datasheet, may give various codes it's
capable of delivering. I can't read the chip number via
the video. I got a high res video and that chip is
glossy and clean, not a lasermark in sight. Not even
signs a cretin sanded off the part number. Just... no number.

PSU +--------------------+
+----------+ | Button|
| Red |--------| Pack LED| Fuel
| |--------| 5*18650 LED| Gauge
| |--------| Charger IC ??? LED| 25% increments
| Green | Shoe | LED|
+----------+ +--------------------+

The PSU is the one flashing codes. Does
that mean the PSU is overheating or weak ?

The pack has a Battery Management IC chip, which should
control charging in CC and then CV mode. Unless there
is a clever serial bus on the third pin of the shoe,
I don't see how the PSU is easily going to learn what
the Battery Management chip thinks about the whole process.

The printed circuit board in the PSU is labeled COM BAT+ BAT-,
implying no serial link on the shoe.

The PSU can tell, from current draw, what is going on.
Zero current is "charging complete". Finite current drawn
is charging. You could flash a green LED for that. If the
PSU is smart, I don't see anything on the single sided PSU
PCB (cheap!) to handle the smart aspect. It would seem
the PSU is dumb as a post. Consequently, I can't even see
it flashing a green LED or a red LED on its own.

If they wanted charge status, they should have moved
the PSU red and green LEDs, to the pack.

I would have to guess the PSU has a problem. It is fan cooled,
using a laptop fan motor. The fan is pointed at the SMPS heatsink.
The PSU printed circuit board has two halves. The mains front
end is one half, and has a bridge rectifier on its heatsink.
There are some filter components on the mains side, for
preventing noise-on-mains.

The SMPS is the other half of the PCB. There really should be
a chip for controlling the Switch Mode Power Supply, but I don't
see it. The switching element (MOSFET???) is bolted to the
heatsink that the blower points at. Don't be rough on the fan,
as fan bearings can be sensitive to abuse.

Usually, if heatsinks get too hot, there is a thermal cutout.
That could be why the red LED is flashing. Check and make sure
the cooling fan still rotates. The cooling fan has two wires, and
has no third wire for RPM or seizure output.

The video is a bit deceptive, because the videographer removed
the cable from the shoe half of the PSU casing which runs to the
PCB. The video makes it look like the two halves of the PSU
come apart easily. When actually, the cable must be removed when the
two halves are ajar. And the cable must be carefully returned
to its mate, while reassembling the unit. The cable is keyed and
only fits on one way, at the PSU PCB end.

It's possible your 20V unit is designed a similar way to this 40V one.
Just a guess.

Paul

On Sunday, January 10, 2021 at 10:35:45 PM UTC, Paul wrote:
Dave Plowman (News) wrote:
In article ect.com,
Andrew Middleton wrote:
I have a florabest hedge trimmer. When trying to charge the battery it
starts off red and after a few minutes it starts to flash green and red.
Is the battery dead?

That is normally some form of cell equalisation. Does the display
eventually change to something else?

This isn't the device in question. It'a a Florabest 40V pack and charger.
It's Lithium and Samsung cells. The pack is equipped with a fuse.

https://www.youtube.com/watch?v=hMMW3v5da4s

Reading the chip number off the 20 pin TSOP, and looking
up that part and its datasheet, may give various codes it's
capable of delivering. I can't read the chip number via
the video. I got a high res video and that chip is
glossy and clean, not a lasermark in sight. Not even
signs a cretin sanded off the part number. Just... no number.

PSU +--------------------+
+----------+ | Button|
| Red |--------| Pack LED| Fuel
| |--------| 5*18650 LED| Gauge
| |--------| Charger IC ??? LED| 25% increments
| Green | Shoe | LED|
+----------+ +--------------------+

The PSU is the one flashing codes. Does
that mean the PSU is overheating or weak ?

The pack has a Battery Management IC chip, which should
control charging in CC and then CV mode. Unless there
is a clever serial bus on the third pin of the shoe,
I don't see how the PSU is easily going to learn what
the Battery Management chip thinks about the whole process.

The printed circuit board in the PSU is labeled COM BAT+ BAT-,
implying no serial link on the shoe.

The PSU can tell, from current draw, what is going on.
Zero current is "charging complete". Finite current drawn
is charging. You could flash a green LED for that. If the
PSU is smart, I don't see anything on the single sided PSU
PCB (cheap!) to handle the smart aspect. It would seem
the PSU is dumb as a post. Consequently, I can't even see
it flashing a green LED or a red LED on its own.

If they wanted charge status, they should have moved
the PSU red and green LEDs, to the pack.

I would have to guess the PSU has a problem. It is fan cooled,
using a laptop fan motor. The fan is pointed at the SMPS heatsink.
The PSU printed circuit board has two halves. The mains front
end is one half, and has a bridge rectifier on its heatsink.
There are some filter components on the mains side, for
preventing noise-on-mains.

The SMPS is the other half of the PCB. There really should be
a chip for controlling the Switch Mode Power Supply, but I don't
see it. The switching element (MOSFET???) is bolted to the
heatsink that the blower points at. Don't be rough on the fan,
as fan bearings can be sensitive to abuse.

Usually, if heatsinks get too hot, there is a thermal cutout.
That could be why the red LED is flashing. Check and make sure
the cooling fan still rotates. The cooling fan has two wires, and
has no third wire for RPM or seizure output.

The video is a bit deceptive, because the videographer removed
the cable from the shoe half of the PSU casing which runs to the
PCB. The video makes it look like the two halves of the PSU
come apart easily. When actually, the cable must be removed when the
two halves are ajar. And the cable must be carefully returned
to its mate, while reassembling the unit. The cable is keyed and
only fits on one way, at the PSU PCB end.

It's possible your 20V unit is designed a similar way to this 40V one.
Just a guess.

Paul
WelI done Paul. I like a man who knows what he is talking about