How to test battery health?

whiteman

Petty Officer 3rd Class
Joined
Oct 7, 2003
Messages
98
Is there a cheap home device to test whether batteries are nearing the end of their reliable working life?

Also, what are your opinions on changing batteries, ie, do you change based upon a time period of say, 3 years?

Safety is my main issue, but I'd hate to get rid of a perfectly good battery because I'm paranoid about safety.
 

Dunaruna

Admiral
Joined
May 2, 2003
Messages
6,027
Re: How to test battery health?

[colour=blue]The absolute cheapest (and best) way is to take the batt to a shop and have it load tested - usually for free. Word of warning, watch them do the test so that they don't try and stiff you with a new battery.

The next cheapest way to test a flooded battery is with a hydrometer - couple of bucks at wallyworld. A reliable and accurate test, but not definative.
 

Texasmark

Supreme Mariner
Joined
Dec 20, 2005
Messages
14,785
Re: How to test battery health?

Totally agree on the load test. AutoZone for one, does that free.

Mark
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: How to test battery health?

Hydrometers can only be used if you can remove the cap from each cell. Load testing and hydrometer testing are both good techniques but they are "right now" tests. They do not give you an indication how long the battery will last. Sort of like going to the Doctor. He checks you over, pronounces you fit as a fiddle and you croak as you are walking out the door. I too, take few chances with my starting battery. It gets replaced every three years. Trolling motor battery is not a safety issue so that one generally runs 4 years.
 

rickdb1boat

Supreme Mariner
Joined
Jan 23, 2002
Messages
11,195
Re: How to test battery health?

I agree. 3 years is the max I will go with the starting battery. For the cost, it's just good insurance....And even though the load test is a right there test, it's the best one to determine overall health of the battery as far as it's ability to start the engine....
 

jtexas

Fleet Admiral
Joined
Oct 13, 2003
Messages
8,646
Re: How to test battery health?

how to test a battery:

http://www.uuhome.de/william.darden/carfaq4.htm#load

Note section 4.5 on battery load testing.

I monitor my cranking battery with a hydrometer every few months at first with increasing frequency as it ages.

If this is an option with your motor...practice rope starting it...just in case.
 

whiteman

Petty Officer 3rd Class
Joined
Oct 7, 2003
Messages
98
Re: How to test battery health?

Great article (if only I understood it!). I'll take the advice to get the batteries professionally tested.

I rope start my 6hp. Now I have to have a go at the 115hp! I can feel a trip to the gym coming on.
 

Boatist

Rear Admiral
Joined
Apr 22, 2002
Messages
4,552
Re: How to test battery health?

I load test mine on the boat. I never had any battery that did not last at least 6 years. I pull the coil wire and ground it to the block, turn on everything on the starting battery, light, blower, Loran C and then crank it for 1 full minute. Let starter cool and do it again. Then I do the same thing with the other battery. Put coil wire back in and start it up and let it charge up. Usually do this before first trip every spring.

With batteries the most important thing is to keep it charged year round. In summer at least once a month and in winter at least every 2 months. Charge with a good automatic charger that will fully charge and not over charge.
 
Top