Classic cars forum & vehicle restoration.

[ukdave2002]

A few folk have PM’d me regarding charging problems with dynamo setups, which is fine happy to help.

One person had this problem; his batteries only lasted him 18 months maximum, as his brother works for a Ford dealer he could buy good quality Motorcraft sealed for life batteries at a good discount, and there lay the problem (not the discount ) but the “sealed for life” bit. One of the reasons that we can have sealed for life batteries is that because of the sophistication in modern electronic charging systems, batteries don’t get “over charged” and consequently hardly gas, so no need to top up.

With the relatively crude control box in a dynamo set up, the battery will gas much more and require occasional topping up, which of course you can’t do on a sealed battery. The same applies to charging sealed batteries with the common cheap battery chargers, you can easily over charge and gas the battery.

If you just use the car for occasional use, probably won’t be a problem, but if like this chap was it was you every day transport, getting started 4 or 5 time a day, avoid the sealed units.

Dave

[Uncle Joe]

UK, you have interested me here, so I have a couple of questions.

Are there any differences between the gel type sealed for life batteries and the acid type, charging wise?

Nowadays, there are electronic regulators available that look identical to the older points type. Do these charge in the same manner as the older ones?

[ukdave2002]

A gel battery simply has the same chemical electroyte, but in a gel form. Some makers do claim to put what would be vented gas back in to the battery, but even these have to have some form of saftey valve to ensure that high pressure is not built up with the cells, so some venting will still occur.

I had a look at some of the repacement regulators when itcame up a couple of months ago, there seems to be more demand for them with bikes rather than cars, they may well have the "battery conditioning/managment" electronics it would seem odd not to use the best technology if you make the change.

Bosh make a direct repalcement for some of its electro mechanical units, I would imagine these would be fine.

[Uncle Joe]

Still making me think, this topic.

One thing that I have a habit of doing is fitting the biggest, most powerful battery I can get on the tray. Originally this was to help starting, but now I'm wondering if it will prolong (sealed) battery life. The charging rate will be the same, so it is proportionally less.

Then again, there are the high amp alternators that are available. For my 300 its easy enough to get hold of a 130A. No doubt if these dont go through a conditioning/management circuit, they could kill a sealed battery very quickly. So maybe these arent such a good idea after all.

[ukdave2002]

Hi UJ

You can fit any size of alternator, it the charging/ managment thats important, modern regulators can detect the state of charge and temperature which are key to getting the charge right, thus protecting the battery.

There is an article here that explains some of what is required far better than I can;

http://www.connectingindustry.com/story.asp?storycode=182290

Interestingly they indicate that 12v sytems have now hit the limit, and that we may soon have 42V systems in new cars.....

[Uncle Joe]

I have finally got round to at least skimming through that article.

Surely the way to go would be 24 volts, not 42....

[Greg]

For a really good Battery I can highly reccomend 'Optima' batteries. The only downside is the cost but for reliability and guts they take a lot of beating, I still have one left over from my days of installing high end car audio systems that I use for camping etc (a bit overkill). They are used in a lot of emergency vehicles, especially in cold climates as they do have amazing ability to deliver a lot of power.

[peter scott]

That's a very interesting thread Dave. I'm using an old vented battery for appearance sake but have occasionally, when acid crystals get lose, wondered if I'm daft. If I ever do have any thoughts of changing anything it will now be my very crude two spool regulator. Just have to mount the modern one somewhere out of sight.

Must preserve the illusion

Peter