Charging warning light LED conversion

[Bob_Spidell]

All this voltage talk has got me to thinking: I installed an AGM battery in the BJ8. These register a somewhat higher voltage--around 13.2V according to the cheapie digital VM plugged into the wiring--than wet cell batteries, which should show about 12.6V fully charged. I also installed a new regulator and these two seem to play well together, at least so far, but the VM shows 15V+ max output. A wet cell should charge at something over 13.5V; wonder if the higher charging voltage I'm seeing could cause problems down the road? And to keep things somewhat OT, the 'battery indicator' light operates as expected--i.e. it goes out at anything over 600RPM or so--but I guess since it shows the difference in potential and the battery/charging voltage delta is about the same that seems to make sense?

 

[John Turney]

Bob, the higher voltage will mean your lights will be a bit brighter and burn out a bit sooner. Other than that, it won’t make much difference.

 

[Bob_Spidell]

Thanks, John.

 

[vette]

Bob, I have an alternator in my BJ7 and a dash mounted voltmeter. The voltmeter routinely indicates about 14 volts while driving. I have had no problems with over charging for many years now. Sometimes is I am on the road for many hours is even on over night trips if I think about the issue of overcharging I might turn on the head lights for a hour or so just to reduce the voltage level so possibly save the battery. With head lights & GPS turned on it might reduce the voltage to 13.5v. I have never seen it go below 13, ever. The battery has never showed an signs of over charged.

 

[Bob_Spidell]

Thanks. I've got over 5K miles on the new battery and regulator with no issues. I was surprised the charging voltage was so high--15V+, and the cheapie VM agrees with my Radio Shack Special DVM--but the AGMs do need a bit more I believe (just shelled out for a Battery Minder maintainer for AGMs only). I sometimes wonder if the regulator wasn't adjusted properly, but so far no problems (I don't think the regulator has a way of 'knowing' it's charging an AGM, unless the current limiting function has something to do with it). With a rebuilt starter, the engine spins almost as fast as the modern geared starter in my Mustang; the 6V system in my dad's T-Bird barely cranks the big lump over.

 

[Novamonte]

Just an update as I started this thread. As per above advide the incandescent lamp remains in the charging lamp. Instead of putting in a new lens (which made it even more difficult to see the light) I painted the bulb with read heat-resistent glass paint. That works fine. I replaced all other bulbs on the dash with LED's. Although not period correct it makes it easier to see the instruments and is easily reversed. I have also added LED's in the rear lights and behind the reflector (for brake lights and indicators). I swapped the single connectors for the brake/indicators in the rear the back to double connectors so I could connect the new LED without having to cut in my new wiring loom - just soldered a bullet connector to the new cable and plugged it in. I have also replaced the front position/indicator light bulbs (5/21W) to LEDs with amber light on the 21W and white on the 5W - makes it easier for others to see the indicators as virtually all other cars use amber light there, and amber position lights are not allowed in this part of the world, so this is a very handy combination (and available with positive earth). I also replaced the flasher unit with an electronic unit. It works well with the LED's and is generally more "distinct" than the Lucas bimetal unit which was quite slow and hesitated for a few second before it started. Finally I put a miniature beeper in parallell with the indicator lamp on the panel as I often forget to cancel the indicators after a turn (the self cancellation is a bit worn and does not always work).

 

[vette]

Novamonte, all sounds good. You did a lot of work.

 

[RAC68]

Hi All,

Bob,

Over 10+ years ago I bought 2 Optima Red-Top batteries (Healey and Acura). After 5 years of use, the battery installed in the Healey seemed to be failing and I replaced the Healey's AGM with the one installed in the Acura in which I installing a new wet cell. When the second Optima (now in the Healey) seemed to also be failing, I called the company and was told to set my charger to 10 Amps in order to stimulate the conversion of some chemical in the AGM that forms when the battery is inactive for an extended period (i.e. Winter storage). After performing a recharge at the 10 amp setting, my AGM has provided good performance since. Before taking my Healey out every Spring, I fully re-charge my AGM at 10 amps and, when driving, my alternator maintains the full charge. Repeated restarts, made much easier using Mobile 1 15W50, show no hesitation to start and I always drive with Headlights (low beams) ON.

Novamonte,
As Vette has already indicated, you have done quite a bit of work. I also applaud your decision to retain your incandescent charge-indicator bulb circuit as not every modernization replacement is a good idea. Good JOB.

All the best to all,
Ray(64BJ8P1)

 

[Novamonte]

Thanks Ray. I have no intention to make further modernizations, I see these as safety issues (and easily reversed). I will keep positive earth, dynamo, suspension, brakes, steering etc. as they are.
Clas

 

[vette]

Speaking of AGM batteries. You might find this a note of interest. I tend to keep an eye on the travels of the fellow known as the MGA Guru. This fellow has been traveling the country for over 2 yrs in his MGA helping anyone with a LBC who hails him for help. Recently his alternator had failed and he hadn't been able to source another but keeps going as long as the car will run. He will pick up parts as needed along the way. The alternator was over charging and he was afraid that it would cook the relatively new AGM battery so he unplugged the alternator. He then traveled more than 475 miles on the battery alone and the battery still read 10.5 volts and had enough power to still crank the engine.