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LTO to Lifepo4 dc-dc charging

Dedou

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Jan 7, 2022
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I have a 35Ah LTO battery as a starter battery in the boat, the charging current of the outboard motor is about 15A, is there any harm in putting an oversized dc-dc charger to charge the lifepo4 battery?

For example, Orion-tr smart 12/12-18A. I want that charger because of the bluetooth application and the adjustable input voltage, but the current limitation is greater than the charging power of the outboard motor.
 
I’m not following your question, motors have watts or amps loads, not charging… the issue with an oversized charger would be max charge rate vs battery rate. You have a 35Ah battery, so 1C rate would be 35A

The issue you need to focus on, is what is the instant load of starting the motors you want to operate.
 
I have a 35Ah LTO battery as a starter battery in the boat, the charging current of the outboard motor is about 15A, is there any harm in putting an oversized dc-dc charger to charge the lifepo4 battery?
Are you trying to charge a battery besides the starting battery with outboard motor's alternator? I don't think I'd want to task that alternator with more than a few minutes here and there of running at it's full 15 amp rating but that's likely a question only the outboard manufacturer can answer.

Regardless of the added wear I'm pretty sure that TR will only take as many amps as the alternator of the outboard can deliver. That's going to result in less than 150 watts of usable charging energy. You'll want to compare that to your expected energy needs.

Victron has a pretty cool thing called the "Demo Library" in thier Victron Connect app that allows you to simulate the installation. You could see if the app allows you to limit the amps of the TR but I don't think it does.
 
Yes, I want to use the outboard alternator to charge the house-battery when the starter battery is full. At first I planned to use an Orion-tr 12/12-9A charger to limit the current of the outboard alternator due to overheating, but apparently this problem is only with high current alternators, many directly charge lifepo starter batteries without problems.
 
Or if I forget the dc-dc charging and put a fet isolator, what happens when there are two lithiums of different chemistry, which one gets charged first?
 
I think the Orion-tr Smart is the best for my use, but if the alternator overheats, any ideas how to limit the current?
 
A DC to DC charge controller.
The links up top on wills page have links to some.
Do you mean solar charge controller? it only starts charging when the input voltage is 5v higher than the battery voltage, it doesn't seem to work. I can't find links.
 
Do you mean solar charge controller? it only starts charging when the input voltage is 5v higher than the battery voltage, it doesn't seem to work. I can't find links.
No, an automotive dc to DC controller.
It is designed to limit the load an alternator will draw.
 
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As I said, a dc-dc charger is exactly what I'm looking for, like the Renogy you suggested, but the problem is too high charging power for my outboard. I want to charge the LTO start battery first at least 14-14.3v and after that the amps go to the lifepo4 battery, this can be done with the orion smart because it has an adjustable input voltage, but the problem with the Orion is that the charging current is too high.
 
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