Battery Voltage / Capacity Meter

[SylvanLakeWH 28,083]

Looking to add three 12 v Battery voltage / capacity meters to my E 141. (It can run on three or six batteries - I’m running with three). Looking for recommendations on type and manufacturers. (Mods I put this here instead of the electric tractors page because it is really applicable to all wheel horses that have batteries and should get better exposure - move if you wish).

 

Something like this, but dash space is limited…

 

 

Appreciate any advice…

[ebinmaine 71,820]

How do these work?

Is it for a specific type of battery like deep cycle?

 

[SylvanLakeWH 28,083]

As I understand it - Any battery. Most have  a range from 6v up to 48 or even higher…They monitor voltage and % power remaining…

[ebinmaine 71,820]

24 minutes ago, SylvanLakeWH said:

They monitor ******** % power remaining

That's the part that's interesting to me. 

(Voltage is easy enough with a dash voltmeter.)

[JoeM 8,164]

1 hour ago, ebinmaine said:

That's the part that's interesting to me.

Back in my EV days, that was all done via calculation using battery voltage.  On a 12 volt battery, 12.7 was considered full, below 11.5 volts < dead or lower than 20% power.

 

Sweep meters used coordinated background gradients as the voltage decreased. New versions used fancy bars like the ones pictured.

 

Battery Maintenance, including charging, was the key to long battery life not to mention a good vehicle performance. 

Good motor controllers will turn off when the battery voltage is to low. This prevents the overheating of components due to high current flow.

 

As far as I know no magic in the gauge.

 

[ebinmaine 71,820]

15 minutes ago, JoeM said:

battery voltage.  On a 12 volt battery, 12.7 was considered full, below 11.5 volts < dead or lower than 20% power

Seems reasonable to me. 

 

Back in the mid 90s when I sold AC Delco batteries we were told a decent battery was 12.45V or higher. 

Anything 10.8 (I think?) Was considered "needs charging" or dead.  

 

 

18 minutes ago, JoeM said:

that was all done via calculation

So basically a battery life gauge is another method of showing available voltage?

 

 

[pfrederi 18,558]

23 minutes ago, ebinmaine said:

 

 

 

So basically a battery life gauge is another method of showing available voltage?

 

 

 Yes and the big issue an older tired battery may show 12.6 volts (100%) but it will drop off much faster under load than a new healthy battery.  So the gauge may show 50% on a battery.  That may mean some cranking left if it was in good shape, or  very little cranking if it is older/tired.

[JoeM 8,164]

And don't forget EV's use a deep cycle battery design.