If you wonder why I'm giving out this information on a cast bullet forum, it is because you are my friends. I hope it saves every reader a lot of grief in the years to come! You'd do well to print it out and hang it on your garage wall for quick reference.
A couple days ago I walked into a local auto parts store, during a cold snap, and saw probably 5 batteries that had been brought in that morning. Though the customesr which brought them in thought they were junk, I would wager that at least 4 of them was in near perfect condition or could easily be if the owners had only known how to take care of them. -- I’m writing this little piece to share some of my 50 years of expensive and hard earned knowledge with you. Hopefully what I share will not only save you a lot of money over the years, but keep you from missing work or being stranded in the wild, etc.
To give you an idea of how and why I’ve learned what I have about batteries, at present I own 13 engines which start with batteries, 5 of them are diesel, which put more demand on batteries than gas engines do. I also live in country that typically gets several cold snaps of 20 below 0 F, and colder each winter, which is when bad batteries show their weakness most. The batteries on most of the rigs I own range in age from about 5 or 6 years for the youngest to something around 12 for the oldest. Yet, until a few years ago, I never expected more than 5 or 6 years from the very highest quality battery. The difference is in understanding more about how they work, how to maintain them and which kind to buy.
Having lived in Arizona for 18 years and in COLD country the rest of my time, I have a pretty good feel of what both high and low temperature extremes do to batteries. Heat is bad, but cold cost’s more people grief over towing and jump start costs and than heat does. Battery cost is only a part of the problem. We often lose a few hours work if we can’t get started in the morning, or have to walk for miles if stranded far out from help or service.
Perhaps the three most important facts to understand about batteries is that when temperature is at 0F they only have half the crank power as at 80 deg F, yet the weakened battery has to buck a stiff engine that cranks 200% harder than at 80 deg ! So, we crank an already weak battery extra hard and long to get an engine started, but then the third and most serious factor shows its face. Cold batteries accept a recharge much slower than at the optimum 80 deg F. It isn’t uncommon for a drained battery to only come up to 12 volts after a good drive in very cold temps, but at 12 volts, and the optimum temperature of 70 deg, it’s output is only half of what it would be if charged to the full 13.5 volts! If you are confused so far, study what I’ve said more closely till the picture forms solidly in your head. It will become more clear as I explain the solutions.
We are stuck with cranking very cold and stiff engines with partial output batteries. So to minimize the cranking force needed, go to full synthetic oil. My favorite is Amsoil, and I believe it’s the only synthitic recommended for diesels. To that add Dura Lube oil additive, which is available at many auto parts stores or Wall Mart. Just follow the directions on the can. You’ll extend engine life dramatically by taking this step, over regular oil. If you are mentally stuck on using standard oil, or can’t believe synthetic is worth its price of $10 per quart, consider using Shell Rotella, which is the most used trucker oil in the US. One of the claims on the oil jug is that engines crank easier with it than any other standard oil. I’ve found that true, with cranking resistence of diesels not too much greater than with Amsoil. By the way, Amsoil isn’t as expensive as its $10 per quart price tag would imply, because it has an extended oil change recommendation of 100,000 miles or 1 year, whichever comes first. (The one year limitation is due to the fact that people who don’t drive a lot of miles tend to drive short distances which doesn’t get the engine hot enough to dry any water or condensed fuel out of the engine. Condensed diesel fuel from letting them idle, especially to warm them up when cold, is a serious problem for diesel engines. I think I’ve owned 9 makes of diesels down through the years and EVERY manufacture very clearly states. DO not idle the engine when cold. As soon as oil pressure shows on the guage after starting, rev it to half speed and work it at half load until temp reaches 140 deg F, then go to full load. This to avoid condensed fuel from getting past the pistons and down into the oil.)
Now, to keep our batteries working at full potential. Quite a few years ago I bought a little volt meter which plugs into a cigarette lighter socket. This one is named ‘volt-I-cator. Others are available at some auto parts stores. Just follow the simple instructions on the side and on the guage face and you’ll extend battery life dramatically if you charge your battery with an electric charger when the guage indicates the need. I no longer use it but use a multi meter. Fairly good ones are available for as low as $20, while the best ones might cost $80. I recommend that every auto or equipment owner get one.
For 12 volt batteries, here are the test numbers which indicate battery condition..
Alternator should charge at least 13.5 volts, better at 14, and 14.5 is fine. If it doesn’t put out at least 13.5 after the engine has been running a while and the battery is charged up some, get the alternator or voltage regulator fixed or replaced. Low charge voltage will soon ruin your battery or let you down.
If a battery, tests less than 12.5 volts after the engine has been turned off for at least an hour, hook up an electric charger and bring it up to full power. It should stand at 12.5 volts or higher after standing unused for a couple hours or more. (Immediately after unhooking a charger or shutting the engine off, your battery will have a voltage closer to what it was charged at, but will drop this ‘surface’ charge quickly, down to the voltage it is capable of holding for long periods.)
At 12 volts the battery is 50% discharged!! 11 volts leaves only 20% of good battery power. At 12 volts it will probably start even a cold engine, and 11 volts will start an engine that isn’t too stiff, but don’t take it out into the wild country on a hunting trip if you can’t get it charged with an electric charger or a long drive, until it will hold 12.5V after setting for at least an hour. If you have such a battery, and it won’t hold at least 12.5 volts for a few hours, put an electric charger on it every night, especially in cold weather. Just a small charger which trickles the battery to optimum charge constantly, is ideal, and inexpensive. If your driving is short, say under 20 miles after starting a cold engine, keep a very close watch on battery charge, and especially after giving someone a jump start. In my ignorant years I gave a co-worker a jump start after work one day, and then drove 10 miles home. The next morning I couldn’t start my own rig and had to replace the battery! Had I hooked up the little electric charger which hung on the wall in my shop, my battery would have been perfect!
To see if the battery is capable of producing good crank power, turn the headlights on for one minute, which will drop the voltage while they are on. It is OK if voltage drops to a little below 12 V during this test. Shut the lights off and see if the battery recovers it’s original voltage in a few seconds. If it stays down, crank power is very low. All battery dealers have battery test meters which do a better load test if you have a battery which has reached this point.
When battery voltage drops to 11, it will have only about 20% of the crank power a fully charged battery which is in good condition. Yet it will still start an engine in fairly cold weather, if the engine is an easy starter.
When voltage drops to 10 volts or less, one can consider the battery to be ‘dead’ or ‘flat’. It is very easy to crank a weak battery down to 10 volts or less and have it not recharge back to above 10 volts when we make short runs, and especially in cold weather. To give an example of what happens with short runs, like under 5 miles. A few days ago I fired up my tractor, in freezing weather, to carry a road killed deer away from the highway. I suppose I had it running for 10 to 15 minutes total, and it has an exceptionally high charging voltage of 14.5, so one would expect the battery would have been at full charge when I shut it down. But out of curiosity, I checked and the battery was down to 60% charge! It is a very large tractor battery and is 8 years old. It is still strong, and I expect I’ll probably get another 2 to 4 years of service from it, but, it has been deeply discharged several times, which reduces maximum capacity even though it has been desulfated as well as possible.
Which brings up the real battery damaging issue when 12 volt battery voltage drops below 10 volts. They sulfate quite rapidly as they sit in the discharged state, much to the delight of battery dealers! For most people, that means a new battery, and the low grade battery dealers make their bucks on the prorated worthless warranty of batteries that are poorly made. Very few will last out 2/3 of the warranty, and with my last two such batteries, 3 and 4 year warranty batteries lasted less than 6 months. Rather than replace them under the warranty, I junked both and bought Delco, which are the toughest battery I’m aware of. I’ve been using them on all my equipment, if they sell suitable sized ones, when I have to replace for about 25 years, after a business man friend told be he used them on his 50 service trucks. His statement, which so impressed me was. “I’ve tried them all and found that it would be FAR cheaper for me to pay double for Delco batteries than to use any other, even if they PAID ME THE BATTERY PRICE TO TAKE THEM! (A battery failure often cost him $300 to $500, back in 1980!
Now about desulfating batteries which have been deeply discharged, and especially if for more than a few days. I know of one tractor dealer in our area who does it at no charge, because they find they make more money on happy customers than on battery sales. But that kind of service is rare and not even available in most areas. You can purchase a good desulfating charger from NAPA and Carquest auto parts stores if you have them special order. Also, companies which cater to those using off grid elecric power, with large battery banks to store solar power, sell them. If you have several batteries, family and friends who you care about, get one, and you’ll never be sorry. It will pay for itself quickly. I bought mine about 4 years ago, and would have had to replace that large ($300) tractor battery and several other batteries that have gone dead for various reasons during that 4 year period, but it has salvaged all of them. It takes a 12 hour cycle to bring what would be a junk battery back to nearly new condition.
I haven’t ventured into the most crippling problem which I’ve had with cheap batteries, and that is internal shorting. This causes them to go completely dead in a few hours, and there is no salvage for them. I never had a Delco short out internally, though I suppose it certainly could happen. It is the one issue which learning all the above will be of no help for.
