jump start units

[monkeyboysee]

hi all,

i been given a Sealey Road Start battery jump start unit.

it was flat as a f**t, i've charged it up until the red lights say it's full, If i put the multimeter across the crocodiles when its plugged in, i get 10.5Vish. Unplugged i get it settled at 9.6v. I'm now timing it to see how much it loses over time.

is 9.6V going to be enough to start my van, its a 1600cc Aircooled?

what sort of timespan would be acceptable for it to start losing charge, before i start thinking the battery is u/s?

if i need a new battery, where do you get that kind of battery from?

cheers

[bigherb]

If it was totally flat and had been so for any length of time then the battery is most probably sulphated and need replacing. But those charging figures aren't good you should be getting a higher reading when it is plugged in over 13V when it is fully charged and 12.6V-12.8V when not on charge. Are you using the wall socket adapter to the DC socket on the front to charge it? If so try using al battery charger connected to the jump leads and see if the readings pick up.

[Hacksawbob]

try http://stores.ebay.co.uk/THE-BATTERY-MANs-SHOP" onclick="window.open(this.href);return false;

[ghost123uk]

Just a thought, are the batteries in these type of units "lead acid" (calcium etc included) or could they be NiCads ?

[monkeyboysee]

thanks guys

i had the wrong charger plugged in!

i've put the right one in, i'm getting 13.6V now. I'm going to leave it to charge for a bit longer and see what readings i get when its unplugged.

what would be a reasonable reading unplugged before thinking its u/s?

[bigherb]

Just a thought, are the batteries in these type of units "lead acid" (calcium etc included) or could they be NiCads ?

They are VRLA batteries.

[ghost123uk]

Just a thought, are the batteries in these type of units "lead acid" (calcium etc included) or could they be NiCads ?

They are VRLA batteries.

I had to look that up

VRLA battery - Wikipedia, the free encyclopedia
A VRLA battery (valve-regulated lead–acid battery) more commonly known as a sealed battery is a lead–acid rechargeable battery

[monkeyboysee]

right, more results from the test. i had the mulimeter probes clamped into the crocodiels all through to give even results.

i charged with a proper charger for the unit, i got 12.4V.

i unplugged at 11.15pm and got 11.2V
7.15am 10.7V
10.30am 10.6V
4.20pm 10.6V
5.30pm 10.5V
7.45pm 10.5V
10.10pm 10.5V
7.20am 10.4V

plugged back in at 7.20am, got 13.4V reading this time

any thoughts guys?

[ghost123uk]

Not looking good to be honest but try the same routine a couple more times as it might come back good in the end.

Or it might not

[California Dreamin]

Lead/Acid battery is made up of 6 cells wired in series...each cell produces approximately 2.1 volts.
6 cells X 2.1 volts = 12.6 volts approximately.

Minus one cell (2.1 volts) = 10.5 volts

Sounds like you have a dead cell.

Martin

[monkeyboysee]

thanks guys,

its back on charge now, i'll post more results later.

cheers

[California Dreamin]

The important reading is the one taken 4 - 5 hours after the battery has been taken off charge.

Batteries will often give a 'high residual' reading after having been on charge, it's what they 'settle down to' thats important.
For a fully charged lead/acid car battery thats around 12.6/12.7 volts (higher on newer calcium/silver products)



Martin

[kevtherev]

It's a dud mate... move on.

[monkeyboysee]

Thanks Kev, noted, too stubborn to quit yet though!!

its now holding at 11.3V without the charger, anyone any thoughts?

at 10.5, is that enough to start the van if i need it?

[ghost123uk]

at 10.5, is that enough to start the van if i need it?

No

Kev is right I am afraid