Checking Batteries

[jimi]

How can I check if my batteries are still OK? Eberspacher not firing up OK and had problems starting engine this afternoon until I managed to semi bump start it by turning it over with flattish battery whilst surfing down big wave!

 

[colvic987]

Hi jimi, I'll have to try that next time i have trouble with my batteries. ????
Where did you say the BIG wave was again.

Will a battery pump and long weight also come in handy.?????

 

[Norman_E]

Beg or borrow a battery tester. These look like an ordinary voltmeter in a metal case, which contains a big resistance coil. When the coil is switched in to circuit the battery's "on load" voltage is revealed. Testing with an ordinary voltmeter will tell you little except the state of charge because no load is being applied. The other method with batteries that have removable caps to enable you to top them up is to use a hygrometer to measure the specific gravity of the acid. This will reveal any failed or failing cells.

 

[jimi]

Biggish waves in Falmouth Bay this afternoon with Easterly F6/7!

Thanks Norman will try and locate the loan of a battery tester

 

[VicS]

[ QUOTE ]
hygrometer to measure the specific gravity of the acid.

[/ QUOTE ] Hydrometer you mean. A hygrometer is for measuring humidity

 

[Pye_End]

Charge the battery (ies) and check voltage whilst appliying a load (eg lights on) - if good size drop then battery gone (assuming you get a good voltage in the first place).

Find that hydometer if not sealed is about the best way without a 'load test'. Normally you find one cell has gone and gives very different reading from the others.

 

[William_H]

The easiest way to test the battery is... first ensure it is fully charged. Use a shore power charger or after several hours engine running.
You need a volt meter connected (held on) to the actual lead posts of the battery then get someone else to try to start the engine. It might be easiest of the stop lever is operated to avoid actually starting the engine.
The voltage will fall even on a good battery but if it drops from 12 volts to less than 8 volts (while cranking) then almost certainly the battery is dud.
If battery volts hold up OK but starter is still slugish then you have a bad connection or even main switch or starter solenoid. Check the connections for warth after cranking. good luck... olewill