Hi all,
I've recently decided to replace my lead acid aux battery with a LifePo4 pack in my campervan.
My current setup charges the Aux batt from the alternator, if the main batt reaches fully charged level.
And it will charge the Starter batt from the solar if the aux batt reaches charged level.
I really like this and it's a feature I'd like to keep. I've looked into DC-DC chargers but have struggled to find any that charge both ways. some have mppt solar input but the max voltage is only around 25V and my array is higher than that.
I'm considering replacing my Epever charger for an Epever Duoracer which supports charging two separate batteries. one can be configured as LifePo4 with the other configured as Lead Acid.
So That's the solar side done, but I still want to charge the aux battery from the alternator. I considered a b2b charger and then realised I could just feed the alternator via a slight step up converter into the panel input of my solar charger. I would disconnect the starter battery from the solar charger when this happens in order to avoid a feedback loop.
I've attached a very rudimentary diagram to explain my thoughts. There's a slight mistake in it that the relay should be drawn as NC, not NO.
Can anybody see any issues with this? Dare I ask? ? Or any better solutions?
Thanks.
I've recently decided to replace my lead acid aux battery with a LifePo4 pack in my campervan.
My current setup charges the Aux batt from the alternator, if the main batt reaches fully charged level.
And it will charge the Starter batt from the solar if the aux batt reaches charged level.
I really like this and it's a feature I'd like to keep. I've looked into DC-DC chargers but have struggled to find any that charge both ways. some have mppt solar input but the max voltage is only around 25V and my array is higher than that.
I'm considering replacing my Epever charger for an Epever Duoracer which supports charging two separate batteries. one can be configured as LifePo4 with the other configured as Lead Acid.
So That's the solar side done, but I still want to charge the aux battery from the alternator. I considered a b2b charger and then realised I could just feed the alternator via a slight step up converter into the panel input of my solar charger. I would disconnect the starter battery from the solar charger when this happens in order to avoid a feedback loop.
I've attached a very rudimentary diagram to explain my thoughts. There's a slight mistake in it that the relay should be drawn as NC, not NO.
Can anybody see any issues with this? Dare I ask? ? Or any better solutions?
Thanks.