I'd worry about current flow from just one of those I have no doubt one of them could happily supply well over 1000 Amps for a short period as i have seen a car started with a 6Amp hour Yuasa
I'd worry about current flow from just one of those I have no doubt one of them could happily supply well over 1000 Amps for a short period as i have seen a car started with a 6Amp hour Yuasa
Bests, Mark
"We must believe in free will. We have no choice" Isaac Bashevis Singer
Location: Middlesex, UK
Posts: 4,481
I'm Alex.
12.8 V is fully charged, that's good, look like gel batteries, so need a charger that will not overcharge them.
Spendorman
When I was aged about 7 I accidentally shorted out a car battery while holding the wires between finger and thumb, an early lesson on messing with batteries and bulbs etc The Smell of burnt skin
A couple of you tube of videos: ( I cant get them to embed for some reason)
http://www.youtube.com/watch?v=-P4iaHPgmg8
-
http://www.youtube.com/watch?v=P11WbduMKhY
-
Location: Middlesex, UK
Posts: 4,481
I'm Alex.
They need a constant current charger, not a normal car battery charger. It needs to be regulated voltage wise & the batteries need to be charged at a maximum of 1/10th the amp hour capacity, better off at 1/20th for longevity.
A 12V gel battery needs to be charged at 13.8V for standby use, i'm not 100% sure for continuous charge & discharge, i'll see what i can find but i think it may be a tad higher
Bests, Mark
"We must believe in free will. We have no choice" Isaac Bashevis Singer
Location: Middlesex, UK
Posts: 4,481
I'm Alex.
That's nothing to what can happen.
At work I saw a large spanner dropped across the terminals of a large lead acid battery. Almost instantly it glowed red then bright red, someone levered it off with a broom handle. Spanner was completely bent.
The battery exploding was a 300+ AH 36V (half ton in weight). There was virtually nothing left of it. Room was filled with smoke and acid fumes. The batteries were used in electric vehicles.
Spendorman
Location: London
Posts: 2,411
I'm Nat-andthat'swhyIdrink.
I'd best make sure they stay in their boxes and away from spanners of both the metal and human kind...
Maplin do sell constant current chargers but perhaps not for this size - may have to splash out on something from RS.
If you can understand this then you are doing better than me
Cyclic charging regime for NP type gel batteries
Cyclic charging.jpg
Bests, Mark
"We must believe in free will. We have no choice" Isaac Bashevis Singer
Location: Middlesex, UK
Posts: 4,481
I'm Alex.
That does look confusing, even after being on a lead acid battery/ charger training course! But that was about 25 years ago.
I have a charger similar to the one below:
http://www.sainsburys.co.uk/sol/shop...966984#infobox
Can safely charge most 12V gel batteries as well as liquid electrolyte ones.
Mine was only about £10 from Lidl
Just found a pic of the Lidl one charging a battery:
http://www.pistonheads.com/gassing/t...969.08575&nmt=
Have to scroll down a bit to see it
Last edited by spendorman; 18-05-2011 at 14:09.
Spendorman
Location: Middlesex, UK
Posts: 4,481
I'm Alex.
Reading the spec of the Lidl charger, It says suitable for Gel or wet 12V batteries of 1.2 AH to 120AH. A "three phase-charging strategy" enablers the charging of the battery to almost 100% of it's original capacity. Furthermore, a long term connection of the battery to the charging station can take place to keep the battery in optimal condition when not in use without it being damaged in the process.
There is a choice of currents, 0.8A or 3.6A and reverse polarity connection protection.
Spendorman