I just completed my multiplus ii 50A install in my 5th wheel. I had a Renogy 200Ahr LiPEO4 but I added a Li Time 560Ahr LiPE04 in parallel, Cerbo GX, and the Panel. Everything works fine. I also have an Onan 6500W genrator, and learned that LiPE04 Batteries should not be used as a starter battery. So I have added a small Duracell U1 Group 300 CCA battery to use for starting the generator. My question is should I be OK using the House batteries to charge the Duracell using the Orion-Tr Smart 12 | 12 30 charger? I can leave my tow vehicle Battery out of it entirely.
There are several good options available. Ideally, you’d use a 5A AC charger to keep the battery in storage mode.
The Victron TR Smart charger is designed to charge a second battery when the starter battery is being powered by the alternator. However, it offers only basic settings: Bulk, Absorption, and Float. It operates only when the input voltage is sufficiently high, though the voltage threshold can be adjusted to your needs.
The Multiplus also includes a built-in trickle charger.
For cranking lithium batteries, NOCO manufactures models suitable for small engines up to around 500cc, if I recall correctly, typically used for motorcycles and similar applications. One option could be to use one of these and connect it in parallel with your main battery bank using an Argofet isolator.
Thank you for the prompt reply, Owen. Still a bit unclear about the answer, though.
I understand the intent of the design using the vehicle’s starter battery. But my question is really basic: If I connect the RV storage batteries to one side of DC/DC Charger, and the generator starter battery to the other side of the DC/DC Charger, will the generator start battery be at least trickle charged?
Seems the answer should be yes, but better safe than sorry. And thanks again!
Best Regards,
Dan Costello, K8GDC
530-305-5418
It will work but not the best product to use. You will need to play with the settings because the lithium bank will rest around 13.2V to 13.1V. If you want it to tirckle charge the whole time the start voltage will need to below the lithium bank. On the output you will need to set bulk absorbtion and float to the storage voltage of the battery. 12.8V for example. I am not sure what the performance will be. Without a storage mode like an AC charger the battery might cycle at the top of the voltage range. See how you go.
Also the current is not adjustable it will put out 30A constant. That will be 30A for maybe a second or 2 till the voltage increases if the battery is full, if its empty could be a bit longer.
Thank you. I will install and let you know (I ordered it with everything else). I will post about ongoing experience as we go forward.
Stay tuned!!!
Best Regards,
Dan Costello, K8GDC
530-305-5418
You might also be able to use the power supply mode and set it to the storage voltage of the battery. ie 12.8V, 13.2V. That should supply a constant voltage. You dont always need to do a bulk charge absorption and equalisation.