Navitron Renewable Energy and Sustainability Forum

Energy/Electricity Storage and Use/Grid Connection => Off-Grid, Batteries & Inverters => Topic started by: Mike McMillan on July 03, 2014, 12:08:54 PM



Title: 3 rather warm hydro caps
Post by: Mike McMillan on July 03, 2014, 12:08:54 PM
Topped up my 2 year old Rolls wet batteries yesterday and noticed that three caps were warm.. the batteries cool. Two were on each end of one battery and one on an adjacent one. One of the cells had used less water, almost none. I guess I need to dig out the hydrometer... maybe switch them around? Anyone else had this?

Mike

Off grid
Osborne Bay
IOW


Title: Re: 3 rather warm hydro caps
Post by: Billy on July 03, 2014, 12:42:58 PM
Hi Mike,

I got Hydro caps on mine and they, on occasion, do get warm.  I don't know why, even the new spare ones I tried got warm but like you say not all.

Seems to happen when they are bubbling away at 29ish V.

Just had a look at this.

http://support.rollsbattery.com/support/articles/19469- (http://support.rollsbattery.com/support/articles/19469-)

Appears heat is a normal consequence of the catalytic magic doing its job but why some and not others?


Title: Re: 3 rather warm hydro caps
Post by: Mike McMillan on July 03, 2014, 08:04:12 PM
Hi Billy,
It is odd, I moved them to another battery and they remain very warm, not hot, but close. I have noticed that the cool ones "rattle" when shaken, but the hot(ish) ones only clunk. I might try for a replacement....



Title: Re: 3 rather warm hydro caps
Post by: Billy on July 03, 2014, 08:48:15 PM
I suppose mine might be coming to the end of their expected life.  Perhaps the spare new ones degrade too.  The blurb suggests a life span of 8-10 years and mine must be eight years now.

I have not tried shaking as I might splash acid everywhere.   :fume

I don't get on with acid, bad trip when I was a puppy.   ;D


Title: Re: 3 rather warm hydro caps
Post by: nowty on July 07, 2014, 08:28:44 PM
Appears heat is a normal consequence of the catalytic magic doing its job but why some and not others?

Remember not all cells are equal, hence the need for EQ charging every now and then.

So the hot ones have reached their full charge first, have reached a higher voltage earlier and are gassing more, the others are still charging at lower voltage and thus are gassing less.


Title: Re: 3 rather warm hydro caps
Post by: Mike McMillan on July 08, 2014, 07:16:04 AM
Thanks for input. The odd thing is, that when I moved the caps to the adjacent battery, the caps remained very warm in their new position, whereas the previously "hot" cells became cool. It does seem to have settled down now...

Mike

Off grid IOW