Alternator Identification

[RichardS]

I think it is an Iskra. Something like this:
http://www.nationsstarteralternator.com/IA0329-12-VOLT-ISKRA-ALTERNATOR-p/ia0329.htm
They are called Letrika now, I believe.

I've never heard of Iskra / Letrika but I reckon you've nailed it!

Richard

 

[JumbleDuck]

I think it is an Iskra.

I replaced the original Paris-Rhône externally regulated alternator on my DS with an Iskra, which is Czech made. It seemed very nicely made and works beautifully.

 

[BabaYaga]

I have an Iskra too, though not identical to the one in the OP's photo.
Beta Marine used them as optional alternators to their standard 40A for the Mini series, maybe still does.
I thought they were made in Slovenia, but could be wrong.

 

[Chris_Robb]

I do, but I am not sure there is much point, since my alternator is regulated to 14.4V anyway. The Adverc can only ever do anything when temperature compensation gets that below 14.2V.

So what does your alternator do when you have been motoring for 12 hours and the battery is well charged? does it keep on at 14.4 V or go to float at around 13.8V?

I think that actually is the problem, in that you need to have the alternator voltage regulated below the standard float voltage otherwise you end up cooking your batteries. Unless of course the Alternators internal regulator is a multistage charger. I think that is what the stirling brings to the party. I know that the adverc supplies alternators, and they will always be regulated at 13.8 for that very reason.

 

[Chris_Robb]

It cannot reduce the alternator output, only increase it, and it won't increase it above 14.2V.

The Adverc is set to increase the voltage to 14.4V. STirling would like you to set his at 14.8 with open LA. Agreed neither can reduce the alternator output - hence my previous post..

 

[JumbleDuck]

The Adverc is set to increase the voltage to 14.4V. STirling would like you to set his at 14.8 with open LA. Agreed neither can reduce the alternator output - hence my previous post..

You are quite right. Bad memory on my part.

The cycling programme is normally: 5 minutes @ 14.0 volts, followed by 15 minutes @ 14.4volts. After four 20 minute cycles, there is a 'rest period' of up to 40 minutes i.e. at the lower voltage, depending on the battery state-of-charge and electrical duty-cycle.

http://www.adverc.co.uk/batterymanagement/adverc-functional-background​

 

[JumbleDuck]

So what does your alternator do when you have been motoring for 12 hours and the battery is well charged? does it keep on at 14.4 V or go to float at around 13.8V?

Keeps on at 14.4V in theory, though temperature compensation can reduce that a fair bit. My car's alternator keeps the battery at 14.4V.

 

[sailorman]

You are quite right. Bad memory on my part.

The cycling programme is normally: 5 minutes @ 14.0 volts, followed by 15 minutes @ 14.4volts. After four 20 minute cycles, there is a 'rest period' of up to 40 minutes i.e. at the lower voltage, depending on the battery state-of-charge and electrical duty-cycle.

http://www.adverc.co.uk/batterymanagement/adverc-functional-background​

So would you agree that in those 14.4 periods, the amps are "ramped-up" above a normally controlled alternator

 

[Chris_Robb]

Keeps on at 14.4V in theory, though temperature compensation can reduce that a fair bit. My car's alternator keeps the battery at 14.4V.

Has the concept that once charged, batteries need to go to float mode gone out of the window? I can't see it being good for them when there is no current draw for a 12 hour run.

 

[JumbleDuck]

So would you agree that in those 14.4 periods, the amps are "ramped-up" above a normally controlled alternator

Not mine, because it's giving 14.4V to start with. Same goes for most modern alternators. 13.8V is so last year, baby.

 

[JumbleDuck]

Has the concept that once charged, batteries need to go to float mode gone out of the window? I can't see it being good for them when there is no current draw for a 12 hour run.

I don't know. Perhaps modern battery chemistry is different. My car battery seems to survive the treatment.