Turnigy watt meter ok for 60.5V ? (Problem solved)

[Diamondback]

Hi everyone.

i am wondering if the Turnigy watt meter will handle 60.5V ?

the instruction manual says 60V max.
im thinking about getting one so i can more thoroughly monitor my battery charge process.
the charger is putting 60.5V (no load).

im running a ping V2.5 48V 15A which is just under 60V fresh off the charger (usually 59.9V).

i have made a harness that allows me to monitor the current going into the battery from the charger
using a DMM, but i figure the watt meter will give me even more info.

anyone know if it will handle my set-up or not ?

Jason.

 

[wineboyrider]

I have run 15s lipo with mine and it survived. That's 61.5. I have heard that 18s+ is what fries them and that they are good to 75v max...., but won't work right higher than 65 v or so...
http://endless-sphere.com/forums/vi...9780&hilit=turnigy+watt+meter+voltage#p429780

 

[Diamondback]

thanks for the info.

ill order one shortly.

Jason.

 

[Diamondback]

just got my watt meter in the post.

have not yet soldered deans plugs on to it, but it's doing something funny when i plug connect it (using jumper wires)
onto the battery charger. it powers up, then quickly cycles between 60.5V and 6v-7V ?

it also seems to read the voltage dropping to about 5V once the charger is switched off.
as soon as it drops below the 60V mark, all is well with the readings.

it works perfectly when connected to the battery (reading 55.7V) and i have also tried it on some 3S lipo packs i have, and it reads them fine too.

maybe it wont work for my 60.5V charger after all.

it might be ok once the battery is connected to the charger (with the meter between them) but im not confident.
i might have just wasted my money on a device that cant do what i need it to.

Jason.

 

[Burtie]

With the newer versions, you need to keep the reading below 60 for it to behave properly (as you found).

You could use a zener diode to drop a few volts on the positive supply to the meter to keep it below 60v, it will still give correct current and Ah readings.

The current is measured only on the black lead.
If you do this, dont use the red lead on the meter to carry the charging current, instead, connect the positive lead from the charger direct to the battery.

Or you could just use an external supply for the meter and leave the red lead disconnected. (details are in the meter instruction leaflet)

 

[wineboyrider]

I guess the newer ones don't take 60.5v...oops. Mine does work at 15s lipo though....

 

[Diamondback]

you could just use an external supply for the meter and leave the red lead disconnected. (details are in the meter instruction leaflet)

my instruction leaflet that came with the meter doesnt show this configuration.

if i leave the red leads on the meter disconnected, run the red (positive) lead straight from the charger to the battery and run the black (negative)
through the meter, and power the meter from an external 6v AA pack, will is still read everything correctly ?

im assuming that volts will be incorrect, what about watt hours and amps ? these are the two im mainly interested in.

or maybe im better to try the first suggestion you made.

if i make a lead that splits the positive from the charger into two, one goes straight to the battery, the other goes through a diode to
the meter, and the negative goes through the meter. this would leave the load side of the meter with only one wire (black) connected,
so i would have to shrink wrap the positive lead to avoid and shorting on anything.

im guessing that due to the 0.6V drop across the diode, this might just work as it would drop the volts to 59.9 at the meter,
but the battery would still be getting the full 60.5V.

what's the better solution here ?
i really do want to be able to use this meter to monitor my charging process.

Jason.

 

[Burtie]

if i leave the red leads on the meter disconnected, run the red (positive) lead straight from the charger to the battery and run the black (negative)
through the meter, and power the meter from an external 6v AA pack, will is still read everything correctly ?

im assuming that volts will be incorrect, what about watt hours and amps ? these are the two im mainly interested in.
Jason.

Just the volts and watt*hour readings will be wrong.


If you want to go the (zener) diode route, you can fit the diode inside the meter casing and then use the meter wiring normally. I have done this ok with about 3 or 4 of the meters I use on 75v, I just insert a reversed biased 15v zener diode.
I think this is the neatest and eaiest solution.

Burtie

 

[Diamondback]

A diode mounted inside the power path inside the meter would indeed be the neatest way to get the meter working.
However, this would mean that I'm running a (slightly) reduced voltage to the battery being charged.

I don't know of this would have any long term impact on the battery ?

It would only be 0.6V lower than intended.

Might give that a go and see how it works.

Thanks for your input.

Jason.

 

[amberwolf]

Not really. Use the negative wire thru the meter for the main power path as normal, but use a straight thru positive wire for the main power path, with no direct connection to the meter. Then use the diode from that positive wire to the meter's positive.

 

[Diamondback]

That sounds like the easier solution.
I won't have to open the meter that way either.

Jason.

 

[Diamondback]

just had an even easier solution given to me.....

i emailed Mr Ping, and asked if placing a diode in-line with the charge lead from the charger would have a negative impact on
the battery or BMS.

i just got his response....

there is an adjustable resister inside the charger itself, and i can safely lower the voltage to 59.9 with no ill effects.
he said it might take slightly longer to cahrge the pack.

i'll opent the charger this weekend and wind down the output voltage to 59.9.
that will solve my issue, and ill be able to use my new watt meter !

ill post up again once its all done.

Jason.

 

[Diamondback]

dropped the voltage on the output of the charger to 59.7 - 59.8V as measured on my DMM. (the reading hovered between 59.7v and 59.8v)
hooked the watt meter up to the charger, and it now reads 59.91V so the problem has been solved !

Jason.

 

[Racer_X]

Diamondback, do you have the 5a charger or the smaller 2a charger for your battery?

 

[Diamondback]

Mine is the 5A one.

Jason.

 

[Racer_X]

Thanks for sharing Jason, I have one of those 5a chargers too and now I know that...

there is an adjustable resister inside the charger itself, and i can safely lower the voltage to 59.9 with no ill effects.
he said it might take slightly longer to charge the pack.

 

[Diamondback]

There are 3 adjustable resisters inside the charger.
The one that varies output voltage is near the fuse on the charger.

You inky have to remove 4 screws on the endplate with the fuse on it.
The little blue box with a small screw ontop is the adjustable resister.

It only took 1/2 a turn to get the required 0.6v reduction.

Jason.