Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Battery replacement-higher charging voltage needed

The original Banner battery served in my +4 2L Duratec MY 2009 unbelievable 14 years. Still functional, but the time for replacement is coming.

The current standard batteries are now all CaCa type (Calcium). This kind of battery needs a higher charging voltage 14,4V - 14,8V. In 2009 the standard usual generator voltage was 13,8V, which was sufficient for the battery types of those times.

However, with 13,8V charging voltage the CaCa battery has problems to get fully charged. It will work also with the original 13,8V, but the life time of the CaCa battery will be considerable reduced.

Did somebody try to adjust the generator's charging voltage to >14,4V with a new voltage regulator or soldering a diode into the regulator circuit to increase the voltage? So far, I couldn’t find a voltage regulator replacement with >14,4V.

Thanks for your comments

Peter

Best solution is not to buy a Calcium battery! They are becoming more popular especially with stop/start cars. But as you have already proven that a conventional battery has performed exceptionally well, then why change? A normal 075 battery from the likes of Halfords will do fine.

Peter, you have two options.

1) Fit a modern alternator that is regulated to a maximum higher charge voltage typically around 14.5 volts.

2) Fit an external smart regulator/booster to your existing alternator. Sterling Power products offer a range of these which electrically piggy back the field circuit of your existing alternator. They are configurable to suit a range of battery charge regimes as well as providing multi-stage charging, including float mode which can increase battery longevity.

TBH I'm surprised you have found or are convinced your present one is regulated to only 13.8 volts at normal engine cruising speeds, given it's modest age. My near 60 year old LR with dynamo charging gives over 14 volts for example.

Finally remember it's the battery to a large degree that limits the alternator output voltage. It's only when close to being fully charged that it allows alternator to hit it's regulated limit as current draw tails off. An aged or faulty battery may be drawing so much current (whilst getting quite warm) that this limit is never hit.

the CaCa battery does not have the same meaning in French

Forgot to mention there is a third option which you alluded to Peter, fitting extra diode(s) into the field circuit after diode trio, although some experimentation may be needed to get desired regulating voltage increase.

See article with rationale here.

Note many car alternators with internal regulation do limit to 14.4 volts. I suspect this is because battery replacements are near universally sealed, maintenance free type of lead/calcium construction. The figure is likely a pitch to cover the fact that only limited reserves of electrolyte are stored within and concerns over evaporation of same.

The addition of calcium in plate construction allows greater rigidity and less gassing at higher charge voltages, safely allowing charge voltages in excess of 15 volts though. I have charged large battery banks of sealed lead/calcium throughout their life at max of 14.8 volts allowing greater charge density and reducing the ageing sulphation process. Out of interest I tore off the tops of a couple before re-cycling and found plenty of remaining electrolyte still covering plates.

A battery not to be sniffed at? 😷

Ask Chris Packham, he should know
https://www.thelondoneconomic.com/n...for-sniffing-wild-goshawk-chicks-355678/

I think your +4 will have the ‘Ford smart charging system’ with the alternator regulated by the ecu.

Rog, is there any evidence for the "Ford Smart Charging System", e.g. specific connector on the generator etc? Because the voltage is quite stable at 14V when engine running, which should indicate an ordinary charging system. The "Ford Smart Charging System" should show something like alternating between 12V and 15V, according driving conditions.

Sorry Peter I don’t know how the ‘smart’ system works but I bet its configured and optimised for lead acid batteries. You would have to monitor it over all driving conditions to begin to understand it. I believe it changes during acceleration and deceleration. But going by memory (as I’m away from my car) the alternator has a small 3 pin comms connector at the back. I believe two of those connections go directly back to pins 59 & 72 of the ecu’s 104 pin connector.