Tomas H.'s SVB Skipper Profile
Tomas H. asked these questions
1
A question about:
Alternator 12V / 115A / Volvo Penta D1 / D2 / D4 / D6
Tomas H.
on Aug 9, 2022
Does this alternator have an temperature sensor as the original alternator has? I have lithium battery bank is it will be charging a lot… so temp controlling is a must.
Answers:
W P. answered
on Aug 10, 2022
Sorry, we cannot yet say whether this alternator actually works in a temperature-compensated manner. We have forwarded your question to our supplier. As soon as we have the relevant information, we will answer immediately. ///\\\ Here are some basic thoughts on charging lithium batteries with a standard alternator: 1) Please remember that alternators are designed to charge lead-acid battery types and even then they are not suitable for reliably and fully charging deep cycle consumer batteries without additional charging technology. Lithium batteries have a lower internal resistance than lead-acid battery types, which is why they can draw very high currents and also stress the alternator thermally. This is especially true at lower engine speeds. At low engine speeds, the alternator also runs at lower speeds, which also reduces the air flow of the alternator fan, resulting in less cooling of the alternator. 2) To fully charge lithium batteries, a constant voltage of 14.6 V is usually required (check your lithium battery manual). Think about using a battery-to-battery (B2B) charger. Most of these devices have a lithium characteristic and, if selected correctly, can also be used as a current limiter to protect the alternator from thermal stress.
W P. answered
on Aug 10, 2022
Here I am again. Our supplier has informed us that this alternator does not include a temperature sensor or temperature compensation. The integrated regulator monitors the voltage at B+. ///\\\ In the meantime I did a little bit research and learned the following. Maybe it is of interest for you.
There are now 3 alternator types, namely those with a fixed voltage (usually 14 V), those with temperature compensation and those which are regulated by the engine electronics (for engines from the Euro 5 and higher emissions standard).
We have to take into account that alternators are designed for the automotive sector and are usually intended to charge a battery (lead-acid type) which is installed closely to the engine. A temperature-compensated alternator should adapt the charging voltage to the ambient temperature of the lead-acid battery in order to avoid overcharging (gassing) at high ambient temperatures and to optimize the restrained electrochemical processes at low temperatures through a higher charging voltage. When the engine is cold, the charging voltage is around 14 V and drops to just a bit over 13 volts as the temperature rises. In any case, this is not sufficient to fully charge a lead-acid consumer battery. Now at the latest you should look in the instructions or in the data sheet of your lithium battery for the required charging voltage and consider whether and to what extent you can charge your lithium battery. If the alternator heats up due to high charging currents at low alternator revolutions, the sensors of a temperature-compensated alternator will react and reduce the charging voltage. This will of course protect the alternator from thermal stress. However, the question arises as to how far and in what period of time you can get the lithium battery charged. If you research a little more on the internet on this subject, you will often be referred to battery-to-battery charging technology, eg. #33047#
Tomas H. answered
on Aug 10, 2022
Then you have to change the description of this altenator... this isnt correct: "identical to the original Volvo Penta alternator"