Anyone Interested In a LCD State of Charge Meter?

[sonicj]

Originally Posted by scottyb

Um.... do more research on potted daylight readable LED 2 wire panel meters for DC...they are accurate. They are out there and I am using them in my carts and others.

i don't doubt that something similar already exists...

some things to consider are that "daylight readable" & "direct sunlight readable" are not the same, LED and LCD are not the same. a reflective or transflective LCD will maintain enough contrast with direct sunlight to remain readable. a segment LED, which is a transmissive device, in the same situation will have a hard time maintaining contrast with surrounding ambient light levels unless its abnormally bright or has some magic filter im not yet aware of.

i would like to avoid potting if possible.... i can't stand when something breaks and i can't fix it or if a new version of something comes out and i can't update my old one.

you're right though, at the end of the day, it essentially does the same thing...
-sj

[scottyb]

Must be magic. We live in SoCal and it is terribly sunny. I have never looked at the meters when I could not read them. The digital aspect is better than a stack of idiot lights. Digitally you can see what your pack is doing under load and under charge ... that's info which will help monitor and diagnose battery and charger trouble.

[sonicj]

how accurate are the digital displays you have experience with? will they follow your DMM through the entire voltage range? how fast do they update under load? just wondering....
-sj

[scottyb]

They are accurate to a 10th of a volt and sample the pack 3 times a second.

[jonequest]

Originally Posted by scottyb

They are accurate to a 10th of a volt and sample the pack 3 times a second.

I think it is bad ***. There are some picky people here. Making it water resistant would not be too hard. Maybe use hot glue. I have waterproofed many circuits with it. It is also fairly easy to pick at and remove when needed for service. Then after you perform a repair, just melt some more on to reseal it, the old left over parts just melt in with the new.

[sonicj]

Originally Posted by Eric_H_E

depending on price and size

this is a good point... what size would you prefer? these character lcds are available in many sizes. the LCD im currently using measures roughly 5" x 2". the case would need to be at least a little larger.

would you guys prefer a surface mount enclosure or flush mount? i like the idea of flush mounting, but it would require cutting the dash. surface mount would be easier to install, but looks more like an afterthought and might be more of a target for thieves/vandals.

for surface mount, i could use a off the shelf enclosure (easy). i haven't found a suitable off-the-shelf weather resistant solution for flush mounting yet.

[ezgokid]

Originally Posted by sonicj

"waterproof" is a big word! to make something like this "waterproof" would likely require potting. this eliminates almost all possibilities of repair outside of warranty, firmware updates or hardware upgrades. "water resistant" is what i would like to shoot for. ie: don't spray it directly with a 3800psi pressure washer. low pressure water hose or rain water would be fine.

i'll take some photos once i have it installed!
-sj

Looks great and legit in the picture, but I have a question. If you claim it to be so accurate, why would it ever need a firmware update?

Not trying to be rude, just wondering.

[sonicj]

Originally Posted by scottyb

They are accurate to a 10th of a volt and sample the pack 3 times a second.

thanks.

Originally Posted by jonequest

I think it is bad ***. There are some picky people here. Making it water resistant would not be too hard. Maybe use hot glue. I have waterproofed many circuits with it. It is also fairly easy to pick at and remove when needed for service. Then after you perform a repair, just melt some more on to reseal it, the old left over parts just melt in with the new.

thanx jonequest!

i'm a big fan of hotglue for all sorts of personal electronic projects! if i build some of these for sale though, hotglue ain't gonna fly those picky folk.

finding a nice looking lcd enclosure and bezel is easy! finding a nema rated enclosure that doesn't look like it belongs bolted on the wall of a school cafeteria is hard!

[sonicj]

Originally Posted by ezgokid

Looks great and legit in the picture, but I have a question. If you claim it to be so accurate, why would it ever need a firmware update?

Not trying to be rude, just wondering.

thanx!

added functionality...

temperature monitoring, mph, data logging, motor rpm, monitoring individual cell voltages, BIG numbers display (one number takes 2 rows), menu functions, gps, alarms, current monitoring, RFID, bluetooth, etc. are all possibilities with the chipset im currently using. Atmel ATmega 328p
-sj

[contender]

I am very interested in one of these. Right now I ride around with a digital voltage meter in glove compartment and folks always ask "why do you have that".