checking spare battery

KC JONES

I had to jump start my car today from a spare battery. How do i tell if the spare now needs charging? It took a while to start and took a few turns but no sign of spare battery dying?

Is it a multimeter I need and can anyone recommend a basic one just for that purpose?

What about http://www.peats.com/cgi-bin/catalog.cgi?view_product=1&id=6514&sid=18&cid=127&scid=592

pajero12

KC JONES wrote: »

I had to jump start my car today from a spare battery. How do i tell if the spare now needs charging? It took a while to start and took a few turns but no sign of spare battery dying?

Is it a multimeter I need and can anyone recommend a basic one jsyt for that purpose

Not very professional way of checking it,but it works.Get two spanners,one on each terminal and touch them together,If theres a good spark the battery is okay,little or no spark means the battery needs charging!
Alternatively something like this..>You could prob get cheaper ones
http://www.argos.ie/webapp/wcs/stores/servlet/Search?storeId=30001&catalogId=1500001801&langId=-1&searchTerms=MULTIMETER&Submit=GO+%3E

KC JONES

pajero12 wrote: »

Not very professional way of checking it,but it works.Get two spanners,one on each terminal and touch them together,If theres a good spark the battery is okay,little or no spark means the battery needs charging!
Alternatively something like this..>You could prob get cheaper ones
http://www.argos.ie/webapp/wcs/stores/servlet/Search?storeId=30001&catalogId=1500001801&langId=-1&searchTerms=MULTIMETER&Submit=GO+%3E

Thanks;)

You could prob get cheaper ones

what about the one i linked?

unkel

KC JONES wrote: »

It took a while to start and took a few turns but no sign of spare battery dying?

You can't trust the spare battery without either measuring or just charging

If you're not bothered about getting a (loan of a) multimeter (the most basic €5 one will do fine), then just charge. If you do get a multimeter, then charge the battery if the reading is less than 13V

Abelloid

Looks fine, just set in the 20v DC range. 12.7 volts is fully charged, 12.00 is very low.

KC JONES

unkel wrote: »

You can't trust the spare battery without either measuring or just charging

If you're not bothered about getting a (loan of a) multimeter (the most basic €5 one will do fine), then just charge. If you do get a multimeter, then charge the battery if the reading is less than 13V

OK cheers;)

KC JONES

JustinOval wrote: »

Looks fine, just set in the 20v DC range. 12.7 volts is fully charged, 12.00 is very low.

Thanks;)

AzureAuto

The problem with checking a battery with just a multimeter is that it wont tell you how the battery wll perform when a large load is applied to it, i.e. the starter motor. Your multimeter may read 12 V or so, but when a demand of a large load is put on it, it doesnt perform, i.e. is too weak to turn the starter over. You can purchase specific battery testers which simulate a starter load on the battery and will inform you, (usually fairly obviously) whether the battery is weak or not. Alternatively, if the battery is still in the car, gert a friend to turn the car over at the ignition, and chek the voltage drop across the battery terminals with your multimeter. The voltage should drop to no lower than 10 V on a decent 12V car battery and then increase to 12.5-14V (depending on the condition of your charging system/alternator).

KC JONES

AzureAuto wrote: »

The problem with checking a battery with just a multimeter is that it wont tell you how the battery wll perform when a large load is applied to it, i.e. the starter motor. Your multimeter may read 12 V or so, but when a demand of a large load is put on it, it doesnt perform, i.e. is too weak to turn the starter over. You can purchase specific battery testers which simulate a starter load on the battery and will inform you, (usually fairly obviously) whether the battery is weak or not. Alternatively, if the battery is still in the car, gert a friend to turn the car over at the ignition, and chek the voltage drop across the battery terminals with your multimeter. The voltage should drop to no lower than 10 V on a decent 12V car battery and then increase to 12.5-14V (depending on the condition of your charging system/alternator).

Are battery testers expensive? Is http://radionics.rs-online.com/mobile/search/searchBrowseAction.html?method=getProduct&R=4183531 OK?
Would it harm the spare battery to charge it if it does not need charging or would it just not charge?
Thanks

AzureAuto

no not expensive, think you can get a decent one for less than 50 euro.
wont do any harm charging a battery that is fully charged, provided the vents to the cells are removed (usually there are 6 on top of the battery and can be removed using a decent flathead screwdriver. Tji si to vewnt any excess hydrogen generated during the charging provess. Also insuer the cells ahve enough electrolyte in them. Take a peek inside the cells and insure the lead is coveed by enough electrolyte, if not pour in some boiled jettle water (once its cooled). Take care when disconnecting any charge from a battery as there could be hydrogen around that is highly flammable. Im talking from experience!

KC JONES

I bought
http://www.wilkinsonplus.com/Car-Maintenance/Auto-Care-Battery-Charger-4-Amp/invt/0120283

at Tesco for around 19 euro. Will this be OK to charge with? From box:
"suitable for most 12 volt 6 cell lead acid batteries from 20 ah to 70 ah"
How do i know if my battery is as above

Thanks

KC JONES

LIGHTNING wrote: »

Its usually written on the side or the top of the battery. Most car batteries for small cars are usually around the 60-70 amp hour range.

Thanks, oh I see ah = amp hour;)
This battery must be used indoors and cell caps removed until charged. Is that usual?

rugbyman

looking for advice on this one.

i have a large motorcycle with a large battery in it. the bike lay up for about si x months ,was jumped ,started and the battery came ok, started it on many occasions and was not ridden.

the battery , one year later is stone flat. the engine will start with a jump. when my new battery charger is applied to the battery for six hours or more the battery still does not have a scrap of life..
the easy conclusion is that it is F..cked. But i am not so sure. my friend tells me that I need an older type of charger to get the battery up from the low point that it has reached. he thinks that modern chargers cannot do this job.

my local motorcycle dealer does not disagree, he suggests, jump start , long ride ,to get the battery over 8 volts and then finish off with my charger.

I may seem like a pernickety c.nt, why not just go and buy one/ perhaps.
Any opinions?

regards Rugbyman

KC JONES

rugbyman wrote: »

looking for advice on this one.

i have a large motorcycle with a large battery in it. the bike lay up for about si x months ,was jumped ,started and the battery came ok, started it on many occasions and was not ridden.

the battery , one year later is stone flat. the engine will start with a jump. when my new battery charger is applied to the battery for six hours or more the battery still does not have a scrap of life..
the easy conclusion is that it is F..cked. But i am not so sure. my friend tells me that I need an older type of charger to get the battery up from the low point that it has reached. he thinks that modern chargers cannot do this job.

my local motorcycle dealer does not disagree, he suggests, jump start , long ride ,to get the battery over 8 volts and then finish off with my charger.

I may seem like a pernickety c.nt, why not just go and buy one/ perhaps.
Any opinions?

regards Rugbyman

I do not know much about batteries but read somewhere that modern chargers can charge too quick for some batteries. Maybe that is your problem?