Low Voltage Disconnet

[force9BOAT]

Hello,

I finally added a load controller to my 24V battery bank.  I've been looking at battery voltage charts on OtherPower.com and the Internet.  They say a 24V bank is at 80% discharge at approximately 24.8V.  But those values are based on a "no load" assumption.  Given a 2 amp sustained load what would be a good recommended low voltage disconnect setting?

Thank you,

Rob

[AbyssUnderground]

With 2 amps I would go with the "no-load" value since the load is very small. I assume the battery bank is large so low currents have a lower effect on the voltage than on a smaller battery bank.

It would also be better to go with a value under-load since it is safer and gives you more piece-of-mind that the battery isnt going below the safe values.

[ghurd]

I believe "12.2V", or 24.4V for a 24V system is the magic number. Load or not.

Below that, sulfation can happen.

The charts are confusing, and often not the same.

I see 23.2V at 80% discharge, 25V at 20% discharge.

http://www.solarseller.com/battery_state_of_charge_charts.htm

G-

[Tom in NH]

I have a 12v solar/battery system with a grid powered charger that switches on when the battery falls to 12.1 volts. A 24v system would just be double that. That's pretty close to what Ghurd recommends. the switch and grid charger makes a very cool system, if I say so myself. It allows me to connect large continuous loads. When the sun shines, the loads run for free.When we have extended periods of cloudy weather, I can continue to run my loads and not worry about my batteries going too low. --tom