up to date volts and amp test results

Hippo · Feb 10, 2015

It doesn't take that much to start an engine. Peeps talk about thousands of amps but in reality it's not. The sudden current demand/spike is high but only for a small amount of time. When yer battery is flat get someone to charge it oft their car for 5 minutes. It will then probably be able to start your car. It doesn't need to be fully charged to start yer car. Charge rate is dependent on the engine revs which is proportional to alternator speed (what the alternator is able to produce, minus what it's powering). Higher the revs means more current available from the alternator, but current will only flow if it's being used. The battery will only absorb so much current at any one time. The link below gives an insight into voltage during starting of ma hippo. I'll do a demo of starting current when I get round to it.

http://www.landyzone.co.uk/lz/f9/freelander-1-starting-charging-voltage-160533.html

gstuart · Feb 11, 2015

Hippo said:
It doesn't take that much to start an engine. Peeps talk about thousands of amps but in reality it's not. The sudden current demand/spike is high but only for a small amount of time. When yer battery is flat get someone to charge it oft their car for 5 minutes. It will then probably be able to start your car. It doesn't need to be fully charged to start yer car. Charge rate is dependent on the engine revs which is proportional to alternator speed (what the alternator is able to produce, minus what it's powering). Higher the revs means more current available from the alternator, but current will only flow if it's being used. The battery will only absorb so much current at any one time. The link below gives an insight into voltage during starting of ma hippo. I'll do a demo of starting current when I get round to it.

http://www.landyzone.co.uk/lz/f9/freelander-1-starting-charging-voltage-160533.html

thks mate

had to read it a few times to get my head round it , an expensive bit of kit

my new varta battery turned up this evening so will see if my neighbour is around to lift it in,my eing the bigger 110 weighs a ton ,I simply can't lift things like this anymore

replaced my hazard light switch and waiting for the rest of my led interior bulbs which should be all here by this weekend

imagine other factors effect battery performanve , ie a bad starter motor and even old engine old and possibly the wrong grade of oil used causing the engine to struggle to turn over ??

trax · Feb 11, 2015

keep in mind he did that with a flat/dead battery. it shouldn't dip to 7 normally.

temperature makes a huge difference

gstuart · Feb 11, 2015

well new battery turned up along with aload of bulbs

at least the courier couldn't throw that over the gate , that will teach them

just waiting for the centre console and boot ones , all leds, plus my cig lighter bolt monitor

should keep me busy and out of mischief for a bit , lol

written down all the types etc for the entire interior so know for the future and in case someone else asks

don't know if it would ever be a good idea to list things like that to an existing sticky

so when I new member comes along can just put a link

ie what size tyres
vcu
auto oil level
bulbs
leak in boot
door motors
resync keys
egy bypass
maf
crankcase filter
synergy box

only a thought, lol

trax · Feb 11, 2015

why you changing everything to led btw? it won't make a difference to your battery unless you turn all your lights on for a long time when the engine is off.

gstuart · Feb 11, 2015

trax said:
why you changing everything to led btw? it won't make a difference to your battery unless you turn all your lights on for a long time when the engine is off.

because there crap, the interior light is poor etc

including the centre console , instrument panel etc

know what u mean but it's just a project I've wanted to do for a while

trax · Feb 11, 2015

gstuart said:
because there crap, the interior light is poor etc

including the centre console , instrument panel etc

know what u mean but it's just a project I've wanted to do for a while

ah, i don't have a fl.. thought they had decent lights.

my 110 was craaap.. i couldn't even read the speed at night. stuck some leds in and it lights it up nice, but they kept going on and off until i moved the wires to wrap around the side; which hopefully has wedged the connections a bit better

i also stuck a strip of led smds down the back..it's like an xmas tree.. daft bright

gstuart · Feb 11, 2015

trax said:
ah, i don't have a fl.. thought they had decent lights.

my 110 was craaap.. i couldn't even read the speed at night. stuck some leds in and it lights it up nice, but they kept going on and off until i moved the wires to wrap around the side; which hopefully has wedged the connections a bit better

i also stuck a strip of led smds down the back..it's like an xmas tree.. daft bright

yes there not great, it's mainly the centre console that where u adjust it to floor, screen etx, they have kept going on and off for ages so out of the 3 x bulbs fitted u end up with just one working

driven me nuts so thought , sod it will change the lot and finish with it

wished to get a brighter interior light mainly so the dogs can see better in getting in and out of the car

as i put them on the back seats and not in the back, so there's plenty of room for them and can stretch out as the boot I feel is too small for them

Hippo · Feb 12, 2015

trax said:
keep in mind he did that with a flat/dead battery. it shouldn't dip to 7 normally.

temperature makes a huge difference

The battery had been flattened enough to show the difference in voltage when settled verses charging. It was still able to start the engine so not too flat. The drop to 7 volts will happen when starting due to the huge sudden load, but it's only for something like 1/40 of a second. The scope picks it up as it's very sensitive.

trax · Feb 12, 2015

Hippo said:
The battery had been flattened enough to show the difference in voltage when settled verses charging. It was still able to start the engine so not too flat. The drop to 7 volts will happen when starting due to the huge sudden load, but it's only for something like 1/40 of a second. The scope picks it up as it's very sensitive.

i use 9.6v min on crank for 15secs.

i've had a goog for the above.

BU-905: Testing Lead Acid Batteries – Battery University

also BU-904: How to Measure Capacity – Battery University but you can't test that at home with a multi

be interesting if you did it again on a new charged battery

edit: assuming the cables and connections are upto snuff! big drops can show resistance of your cables

Hippo · Feb 12, 2015

Even on a new fully charged battery volts would drop, but only for a split second. The sudden load applied when the starter connects causes this. After the split second you see the volt drop caused by the starter running. If it didn't start and you switched off the volts would rise a bit to the more natural state of the battery. It's the loading on the battery causing all of this. The split second volt drop isn't anything to worry about. Scopes can easily measure millionths of a second so they capture everything. It's not proof the battery is good or bad. It's just giving an insight into what's happening. The scope is a toy I have a work.

trax · Feb 12, 2015

Hippo said:
Even on a new fully charged battery volts would drop, but only for a split second. The sudden load applied when the starter connects causes this. After the split second you see the volt drop caused by the starter running. If it didn't start and you switched off the volts would rise a bit to the more natural state of the battery. It's the loading on the battery causing all of this. The split second volt drop isn't anything to worry about. Scopes can easily measure millionths of a second so they capture everything. It's not proof the battery is good or bad. It's just giving an insight into what's happening. The scope is a toy I have a work.

aye, i mean from full 12.6v (or whatever your old one is) it shouldn't drop below 9.6v@10c on cranking even for a split second. if it does then it is bad or going bad

it'll still work, but it's not running at what's on the label anymore, as it's slowly making it's way to the battery heaven in the sky.

Hippo · Feb 12, 2015

trax said:
aye, i mean from full 12.6v (or whatever your old one is) it shouldn't drop below 9.6v@10c on cranking even for a split second. if it does then it is bad or going bad

it'll still work, but it's not running at what's on the label anymore, as it's slowly making it's way to the battery heaven in the sky.

The sudden induced load is something in the order of many hundreds of amps. That's the split second load causing the split second drop to 7v, not the same as the running load which lasts for about 1.5 seconds. After the split second the starters only dropping/loading the battery down during the phase of 10 to 11.3v as it slowly recovers at the same time. It's true a better/full charged battery which settles at about 13v+ after charge will hold better during the start phase, with the volts not dropping so low during the 1.5 seconds. But not by much of a difference unless the battery is larger. If mine in the test had been charged better it would still drop but not as much. I will get hold of a newer battery and do the test again when I have time. got to replace me ball joints this weekend and other stuff to do after that.

trax · Feb 12, 2015

yeah, that would be interesting if you could graph it.

good luck with the ball joints, it's meant to get chilly!

gstuart · Feb 12, 2015

very interesting reading, I think i understand it about the volts dropping as it starts , the same way when a bulb is put on and reqs demand ,

have been searching through these split charge systems so I can use the other battery , it is a different AH and cca , but assume that doesn't matter as long as there both 12 volts set in parallel

think the boot may be the best place, was thinking of a battery box to seal it and put a tube on the top as its not a sealed one then drill a very small hole and put a tube from the battery then through the rear panels , to outside or though an existing grommet in the floor , to ensure it vents to outside ,

can I ask a daft question what kind of split charge amperage would I need as they sell from a 70 amp upwards

sorry in asking daft questions but , this will be a good little project , I assume with regards to wiring it up that the leads simply come off the existing battery, was thinking of running the cables under the car as there's the big grommets in the boot floor and can secure it all the way under the car, well my son can , lol

The Mad Hat Man · Feb 12, 2015

"but assume that doesn't matter as long as there both 12 volts set in parallel

"
Wrong - Always isolate the two as otherwise the lowest power one will drain the better one.

solit acharge realy at least the same as the alternator output.

gstuart · Feb 12, 2015

The Mad Hat Man said:
"but assume that doesn't matter as long as there both 12 volts set in parallel

"
Wrong - Always isolate the two as otherwise the lowest power one will drain the better one.

solit acharge realy at least the same as the alternator output.

see I mustnt assume all the time,lol

wouldn't the split charge automatically go over to top up the second battery or is that the more complicated systems that do that ,

sorry what does. solit a charge realy mean plse,dam autocorrect , was trying to work out what u meant

unless u meant split charge , think my alternator is 150 amps ,

thks again mate

The Mad Hat Man · Feb 12, 2015

a simple split charge system just uses a (powerful) relay which switches current through to the second battery when the engine is running (charging).

more sophisticated types monitor the voltage of either or both systems and send the charging current to the respective battery.

The Mad Hat Man · Feb 12, 2015

look in the CFAQs section for a simple system

gstuart · Feb 12, 2015

thks again

funny enough just came across this site

About Split Charge Systems

defentely a lot more complicated than i first thought , that's why I go into something with great details and plan to see what's involved before I do anything

up to date volts and amp test results

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