Battery went dead in truck

[Scott_in_WVA]

Really....
1 month left whats it going to be worth,15 cents?

 

[patrickg]

No Scott, that isn't the way it usually works with prorata warranties. You probably wouldn't get the whole 15 cents Read the fine print. No one hardly ever actually sells batts at list price except to folks making a claim under warranty. For example: you buy a 10 month warranty batt for $10 and it lasts 9 months, you think you have $1 or 1 month left in the batt that they owe you. The replacement costs $25. They credit you with $1 and you pay $24. How many months did your one month you were due, buy you? The answer is: 0.4 months. Again, read the fine print.

I knew a guy that had tires with a prorata warranty and would expect to get the same treatment as with the batt case above (tire prices are highly variable and subject to whatever the seller wants to do). This chap also had road hazzard warranty for free replacement, including mount ballance and labor (don't ask me how he got that) as long as the tire had legal tread and he had records of following their recommended rotation period. So, just before the tires wore out two of them failed when he hit a highly suspicious and probably mythical mystery object in the highway. I don't know what actually happened but I suspect it was something simple but clever.

Likewise his umteen month battery failed just inside the "free replacement" period before the prorata cut in. I think he poured out a lot of the acid from one of the cells so it couldn't be charged or some such. This was a guy that everyone in the squadron used to count their fingers after shaking his hand. This guy could have been sleaze coach to Bill Clinton. The kind that if a balconly gave way with the two of you it was a a certainty that you would hit the ground first and cushion his landing.

Patrick

 

[Scott_in_WVA]

/w3tcompact/icons/laugh.gif...Patrick I love the way you tell it.
Thanks

 

[Ozarker]

I didn't mention the different types of deep cycle batteries because I doubt you have the "wrong" type. They two types are marine and industrial (sometimes called traction batteries). Marine batteries, what you usually get at the walmarts of the world, are actually hybrid batteries and are a cross between a cranking battery and a deep cycle battery. True deep cycle batteries are made with thick lead plates and are very expensive. Automotive cranking batteries and Marine batteries are made with thinner lead sponge like material.

The problem with your trailer battery isn't necessarily that you have the wrong type of battery but that you have the wrong size battery for your application. One cycle = one discharge recharge. A deep cycle battery is designed to discharge up to 80% before recharge back to 100%. If you are discharging till dead in your application, more than 80% discharge, you need a higher amp rated battery. Or maybe you need 2 batteries. A 50% discharge cycle will extend the life of the battery(s).

 

[patrickg]

I think ozarker and I are almost in violent agreement now. Right on! If you use true deep cycle batteries, like golf cart batteries for example, you will get a good service life (number of recharge cycles) but it will take a significant volume/weight of batteries to supply the current required without warping a plate or doing some other injury to the battery. This is THE solution. If you use the "hybrid" you will do better than starting batteries but not as good as with THE batteries. True deep cycle batts are the more expensive (front end loaded) solution but over time can be the cheapest solution, especially if the down time due to batt failure and repetitive replacement matters.

Also regarding the comment about using a starting batt for lights. Deep cycle is the right way. You get away with it if the draw is really low, short duration, and you don't draw the batt down nearly as far as you would with a true deep cycle. If you try to use a starting batt for deep cycle service it is very expensive and failure prone. This is a lesson soon learned by newbies in solar electric applications, campers, and similar apps.

I did get excellent results using starting batts in one "alternate" application, welding. Once as a consultant to a startup company trying to perfect a battery operated arc welder (34 lbs without batts) I used 100AH starting batts with good results. They would source the heavy current required without premature failure but you had to recharge earlier that if you had a bank of deep cycles. Of course with deep cycles you would have needed a trailer to haul the battery bank as each safely sources much less current than a good diesel starting battery. A it was I used two 100AH 12volt diesel starting batts in series with one being charged by the vehicle and the other floating. Had a switch arrangement to reverse the roles to keep everyone charged (simpler and cheaper than a 24 volt alternator.)

It is a pay me now or pay me more later situation. Go cheap and you replace often. Go first class and it costs more, weighs more, and takes up more space.

Patrick