David Roden wrote:
On 23 Apr 2009 at 13:34, Christopher Zach wrote:Not easy to do with T105's, easy with BB600s. But even then you're looking at 30 monitors which each will take power.....Yeah, that's the rub, isn't it? OTOH, you only really need them when you're running the vehicle, and then they're a trivial percentage of the energy that it's using. If you use them when you're charging ... well, the energy to run them comes from the mains.
True, the problem is they unbalance the pack, even at 5ma or so. 5ma is close to an ah a week, if the car is sitting for 4 weeks that could unbalance the pack some.
Also, practically speaking, it's hard to sort out 30 or more little indicators in front of you. Now you start to get into something like a microprocessor to monitor them for you. You can really go overboard. The good news is that flooded lead batteries are pretty tolearant of moderately careless use.
The human eye is actually an amazing processor. You can look at a field of 30 lights and instantly see one that is different from the others. Takes but a second.
Now that I know how to build op-amps, I've thought about building my own monitor with a pair of op amps and an opto-isolator to saturate if voltage goes >14.7 volts or under 10.5 volts. Much simpler than the zener diode trick. Hm. I should build that now.
Chris