Battery Maintenance

[Chris KC]

I had a stimulating chat with the commendably helpful staff at Shield Batteries of Bishop's Stortford ("Battery Charged is the on-line division of Shield Batteries and we are the last independent manufacturers of batteries in the UK, as well as the manufacturer of hard rubber batteries").
 
No doubt 'old hat' to some, but if you've been wondering why your increasingly costly battery dies every couple of years the info below (slightly paraphrased from original text for your convenience) may be of interest - particularly as some among us may be just about to lock up the garage for the winter:
 
"We ship out via FedEx and the acid packs are generally shipped in a separate box from the battery itself. 
 
A dry-charged battery is not live, so theoretically it can be put on the shelf and left for a very long time.  If you plan to do this, bearing in mind most sheds and garages tend to be a little bit dusty and full of spiders it would be a good idea to keep it wrapped against the elements.
 
Once the acid is added to the battery, it is then live and, as you are aware, will self discharge and will need to be kept charged.
 
Your best bet for that would be to have a 6V intelligent charger.  When the car is not in use, you simply plug in and forget.  The charger will kick in and out as and when the battery needs to be topped up. 
 
In addition, keeping the battery topped up like this will keep sulphation at bay.  Sulphation sets in when the battery is discharged and left / kept discharged (or not properly charged) – the sulphur that attaches itself to the lead plates crystallises and doesn’t reabsorb back into the electrolyte – thus compromising the battery. 
 
The pitch cracking on the top of the battery is usually caused by the battery being allowed to sulphate, which causes the plates to expand; as the top of the battery is the weakest part the resulting damage is cracking in the pitch.
Extremes of temperature can also result in the pitch cracking, for instance if the vehicle is left in a warm garage during the summer which becomes very cold in winter."
 
"As a rule of thumb the higher the ampere-hour rating the better, however I take on board your comment regarding the Dynamo. If you are heavily discharging the battery you may have trouble re charging it with a Dynamo. Having read the e mail trail it sounds as though you are not placing heavy demands on the battery, so the Dynamo should be capable of keeping the battery charged whilst using the vehicle.
 
I note Alan’s comments relating to a smart charger & agree that would be the ideal way of maintaining the battery charge & health especially if you are not using the vehicle on a regular basis."
 
The key message here is if you hope for your battery to last a few years, don't allow it to go flat and stay flat while your car is 'lying fallow'. Hope this is of interest.

[Reckless Rat]

I have a 6V/12V Accumate which I use to keep the RP charged when not in use. The battery is a 6v 80AH and was new in 2008. Still OK so far (hope I'm not tempting providence)

[Hedd Jones]

Two new batteries for me this spring. Both fubar.

[Bob Culver]

The advent of Low and No Maintenance batteries has altered much of the following traditional information about batteries.

Life is shortened by long periods undercharged or, worst, flat, by overcharging, and by repeat cycles, especially deep, and by a lot of very slow charging (as distinct from floating). In their day most Sevens suffered the first three and life was often short.

For typical modern use, with little night running, a modest summer charge perhaps interspersed by none and maintained by a modern bench charger would seem near ideal, provided initial charge rate when low is about 4amps min (for 80 ah) and voltage on charge is suited old style batteries, and does not exceed about 6.9 v after initial charge.

[Hedd_Jones]

The advent of Low and No Maintenance batteries has altered much of the following traditional information about batteries.

Life is shortened by long periods undercharged or, worst, flat, by overcharging, and by repeat cycles, especially deep, and by a lot of very slow charging (as distinct from floating). In their day most Sevens suffered the first three and life was often short.

For typical modern use, with little night running, a modest summer charge perhaps interspersed by none and maintained by a modern bench charger would seem near ideal, provided initial charge rate when low is about 4amps min (for 80 ah) and voltage on charge is suited old style batteries, and does not exceed about 6.9 v after initial charge.

Bob, starting a car on 6V with the starter gives the battery a lot of stick, a lot more than on a 12V car (about double would you believe?). So a 6V battery will always last less than a 12V equivalent.

The two cars I have on the road, one will always start 2nd or 3rd pull on the handle, so I'm not using the starter at all. I'll drive it anywhere as I know it will start. The battery will barely spin it over in anycase. But on the move the current given by the dynamo means its ok with the lights on. The other car, a poorer starter, needing considerwable cranking, the battery will put a good effort in of a morning, but I have the issue if I drive it somewhere, and leave it all day, the sod might not have enough go when I come to start it. And it pretty much wont go on the handle. Ive taken to charging it all night. Get up earlier than I want to leave. Get it started, then put it back on charge untill I'm ready to go.

[Erich]

I am not familiar with these issues with wet batteries. However, I worked in the film industry for three decades and making sure that the batteries lasted and would carry a full charge was very important. Initially, the batteries were Nickel-Cadmium, but in the '90s I switched to the newer Lithium-Ion. Some issues that could damage the batteries, were allowing the batteries the drain below their threshold level, as well, overcharging would damage the batteries. In my case I had a smart charger that would ensure the battery was not over charged and would detect if there was excessive heat. Additionally, I fabricated a battery drain with cut out once the threshold limit was reached, then on the smart charger they went. The difference between the Ni-Cads and Li-ion and lead acid, is the latter don't have a memory as part of their function. With the former, if a battery is only partially drained and then recharged and this cycle is repeated, the battery can develop a "memory" of how much charge it will take. Mostly academic, but the point that I am making echoes what the staff from Shield Batteries is making. Letting the charge drop in any battery bellow the lower threshold, or over charging, will shorten the life. As smart charger will keep the battery properly charged.

Erich in Seattle

[Dave Mann]

Having 4 cars all negative earth can anyone explain why one has developed a habit of growing a fur coat on the negative terminal.

[Hedd_Jones]

Having 4 cars all negative earth can anyone explain why one has developed a habit of growing a fur coat on the negative terminal.

leaky post

[Dave Mann]

Thanks Hedd, there was a hole in the post.