Model Boat Mayhem - Forum

Technical, Techniques, Hints, and Tips => Batteries & Chargers => Topic started by: tizdaz on February 13, 2018, 03:19:46 AM

Title: When to charge?
Post by: tizdaz on February 13, 2018, 03:19:46 AM
Hi guys, just a quick one


I have a voltage LED display that shows current voltage of my 12v cel, question is at what voltage should i disconnect & recharge, its a 12v 22AH gel cel as i know i shouldn't let it drop too low?


cheers :)
Title: Re: When to charge?
Post by: malcolmfrary on February 13, 2018, 09:05:02 AM
If a 12 volt battery gets below 12 volts, its time to charge.  If it doesn't make it to at least 13.5, its time to change.  Either way, its a good idea to check the calibration of the display device against something of known accuracy occasionally.
In a multi battery set-up, it is a good idea to make sure that the battery being reconnected is the same voltage as its mates, a small difference can give a very big circulating current as they even out.  If they connect through a schottky diode unit, the highest voltage one carries the load until its voltage drops down to equal the next, then they bot carry the load.
Title: Re: When to charge?
Post by: tizdaz on February 13, 2018, 08:48:49 PM
ok thanks :)
Title: Re: When to charge?
Post by: Peter Fitness on February 13, 2018, 09:16:22 PM
Following advice I received many years ago, I always recharge my SLA batteries after every sailing day, and store them out of the boat fully charged. A couple of them are over 8 years old and still delivering full power, I don't have a digital read out, but charge as a matter of course.


Peter.
Title: Re: When to charge?
Post by: BrianB6 on February 13, 2018, 10:00:23 PM
I agree with Peter, always charge straight after sailing.   My charger shows a red LED whilst charging and a green LED when fully charged ( was not all that expensive although I have had it many years)
Also try charging after a month or so just to top it up.  SLA's should be kept fully charged.
Title: Re: When to charge?
Post by: tizdaz on February 13, 2018, 11:59:42 PM
great info thanks guys, i wasnt too sure so will just charge after each sail :)