Community Question

I'm curious about NiMH battery warnings from the EZ-B. As I'm using an NiMH battery pack to power a v4, I have the LiPo battery warning disabled from within the "Connection" control in EZ-Builder. I have never had my 7.2 NiMH run so low as to disconnect my EZ-B's connection and today it happened for the first time.

When the v4 disconnected from EZ-builder, I thought this was due to a signal dropout. I power cycled the v4 and tried to re-establish the connection only to be greeted with the verbal "My battery is low" message. So does the EZ-B have a secondary battery warning system then, or have I missed something other than disabling the LiPo battery warning in the connection control?

I know a v4 shouldn't be powered with anything under 4.5 volts and didn't get the chance to see what the voltage was on my 7.2v NiMH before the v4 disconnected. Sorry if it sounds like a daft question, but this is the first time I have come across this and was curious.

Cheers.
Steve G
Commented July 2015
Okay, I'll take a final stab at hopefully finding a plug n play solution. I found this meant for an Arduino during a web search and wanted any thoughts on maybe using this with an EZ-B. It can be hooked up either by ADC or digital ports and hoping this might be an easy solution to what I'm looking for. Any thoughts?

Battery Overvoltage Undervoltage Detection Sensor Module for A29 Arduino


User-inserted image
Dave Schulpius
Commented July 2015
May work but it's not available anywhere I can find.
Steve G
Commented July 2015
@Dave.

Lol, yeah there is that. I had similar trouble. However there is a company in the UK that sells them but are currently "Out of Stock", but I have emailed them asking when they are likely to get some more. Fingers Crossed.
Steve G
Commented July 2015
@Dave.

Good news. I managed to find somewhere that had them in stock...

Under-voltage over-voltage sensor

It will take a couple of weeks to get here as it's coming from the U.S. to the UK, but that's no problem. I just hope it will work.

Watch this space... ;)
Steve G
Commented July 2015
@Richard and anyone else using NiMH battery packs.

In post #2 when you (Richard) said "I believe it is something like 1V per cell", you wasn't far off the mark, as I have since seen it said here and there on the interweb. I did also ask on a website for a company called "Overlander" before I got your reply and received an email response this morning...

Quote:

Dear Steve Gibbs,

New answer was just posted to your question regarding .

Your question:
Hi there. Could you tell me, what is maximum under-charge voltage I can go for the 3800mah 7.2v premium sport battery pack, before permanent damage occurs? Thanks in advance.

Answer:

Hello,

Each cell can't go below 0.8v for a Nimh, before permanent damage occurs so in this case the pack can't really go below 4.8v.

Hope this helps
John

Thank you again,
Overlander




So good to know knowing the overall 4.8v threshold of a 7.2 NiMH pack. Below is a link to the website for anyone interested...

Overlander Batteries

Question
AvatarSteve G
Asked on Saturday, July 11, 2015