I Know that Jeremy posted a nice simple battery meter project a while back but thought I would show you an even more simple one that works really well, is totally analogue and bullet proof and is dirt cheap 8)
On my battery my pack capacity drops in direct proportion to the displayed voltage as with most chemistries of course but with Lipo this can be seen clearly, I have a watts up meter in the rack on the back of the bike but I wanted a quick glance meter for the front of the bike so on long rides I dont have to keep stopping and checking the meter in the bag on the back of the bike.
I used to use a 24V one on my last rig and it worked so well, 4QD sell these little battery meters here in the UK, their website is really old fashioned but they have been around for years and are fine to deal with, the 7 Segment meter can be had for 10 UK pounds! a total bargain, they will also make them to your battery spec if you need them to.
I will attach it with a bit of sticky velcro to all my rides making it quickly removable, this works as a great cheap ebike fuel gauge, I also run my Lipo buzzers on the back too for extra safety.
So if you want a hot swappable, super cheap, reliable and durable battery meter I dont think you can really beat this?
I will post a picture of it and a little clip of it working in the week some time, they ship to the rest of the world as well.
The LEDs extinguish at approximately the following voltages (other specifications to order):-
7 LED (48v) 5 LED (24v) 3 LED (12v)
LED 1 49.7 - 49.2 Green
LED 2 47.9 - 47.4 Green
LED 3 46.1 - 45.6 25.1-24.6 12.3 - 11.8 Green
LED 4 44.3 - 43.8 23.3-22.8 Green
LED 5 42.5 - 42.0 21.5-21.0 10.3 - 9.8 Yellow
LED 6 40.7 - 40.2 19.7-19.2 Red
LED 7 38.9 - 38.4 17.9-17.4 9.0 - 8.5 Red
http://www.4qd.co.uk/prod/bcm.html
On my battery my pack capacity drops in direct proportion to the displayed voltage as with most chemistries of course but with Lipo this can be seen clearly, I have a watts up meter in the rack on the back of the bike but I wanted a quick glance meter for the front of the bike so on long rides I dont have to keep stopping and checking the meter in the bag on the back of the bike.
I used to use a 24V one on my last rig and it worked so well, 4QD sell these little battery meters here in the UK, their website is really old fashioned but they have been around for years and are fine to deal with, the 7 Segment meter can be had for 10 UK pounds! a total bargain, they will also make them to your battery spec if you need them to.
I will attach it with a bit of sticky velcro to all my rides making it quickly removable, this works as a great cheap ebike fuel gauge, I also run my Lipo buzzers on the back too for extra safety.
So if you want a hot swappable, super cheap, reliable and durable battery meter I dont think you can really beat this?
I will post a picture of it and a little clip of it working in the week some time, they ship to the rest of the world as well.
The LEDs extinguish at approximately the following voltages (other specifications to order):-
7 LED (48v) 5 LED (24v) 3 LED (12v)
LED 1 49.7 - 49.2 Green
LED 2 47.9 - 47.4 Green
LED 3 46.1 - 45.6 25.1-24.6 12.3 - 11.8 Green
LED 4 44.3 - 43.8 23.3-22.8 Green
LED 5 42.5 - 42.0 21.5-21.0 10.3 - 9.8 Yellow
LED 6 40.7 - 40.2 19.7-19.2 Red
LED 7 38.9 - 38.4 17.9-17.4 9.0 - 8.5 Red
http://www.4qd.co.uk/prod/bcm.html