Mistakes Easy When You know How !

nigtomdaw

The other day I read a post which Creezer had answered a question on BTS compensation and I think if memory serves me well 0.03 v per degree for a 12 volt system. I also posted around the same time commenting on seeing my batteries drop to 23.9v one cold morning recently the first time Id seen them below 24v under load ever. The following morning I saw them at 23.7 v under load and thought um all is not well. I also couldnt remember seeing my batteries go passed 28.8 volts when on generator charge. They used to last year in winter go above 28.8 volts as high as 29.9 with battery compensation from my SW3024E. I had a problem.

The only thing that has happened in the year was a relocation of my complete system to my solar shed from the house.

I checked that my BTS were fitted to both my C40.s Located my Inverter BTS attached to the batteries, correct, followed it through the conduit up to the inverter, duh not plugged in !!. See its easy when you think you know what your doing. Plugged it in then inverter read Battery voltage 28.0v Compensated value 27.3 volts. That evening it took 4.5 hours run time to get the batteries to absorbion mode when it was only taking a couple of hours before. Weve only been inthis cold snap for a couple of weeks so hopefully little or no harm done

I read this forum most days to keep in touch and learn as much as I can and help were possible , just like to thank those that post for help and the experts for years of expierence,a great forum especially for clots like me who cant remember to put a plug in a socket.

crewzer

Re: Mistakes Easy When You know How !

8)



Jim / crewzer

System2

Re: Mistakes Easy When You know How !

Speaking of BTS compensation, I received the following from East Penn, re the L-16 batteries I have of theirs and would like the opinion of some of the experts here. Thanks a lot.

"for 25°C, the temperature coefficient is 0.005 mv / deg C."

I suspect they meant 0.005 V / deg C, not 0.005 mv. ??????
Just want to be sure
Thanks a lot
Wayne

crewzer

Re: Mistakes Easy When You know How !

Wayne,

Technically, I believe it should be "-0.005 V/2 V cell/degree K, ref 25 C".

For a 12 V battery (six 2 V cells in series), a common TC expression is -0.03 V/degree C. For a single 6 V L-16, it would be -0.015 V/degree C.

The minus sign is important. It means that charge voltage is reduced as battery temperature is increased, and visa-versa (= inversely proportional).

HTH,
Jim / crewzer

System2

Re: Mistakes Easy When You know How !

Thanks a lot Jim, I knew you'd have the answer

Wayne