Recent content by SV_Stray_Cats

Not yet. I'm not sure I will since my goal is to keep them out of the high and low voltage so why would I put them there on purpose....well so that I know they can do what they say and that I can depend on them. First I need to stop the BMS from complaining. It's either very sensitive or it's...

Hello, today I finally connected the cells in their locker on the boat. What I want to mention is relevant to any DIY installation of Lishen cells like this. They have a larger contact pad lower than the one that has the stud/post in it. I imagine these are used in OEM applications, but their...

Hi, I'm putting my fuse and battery switch right next to the battery, before the BMS. That way the fuse protects all the wiring and the BMS, and the switch gives me a way to switch off the BMS. That's rare, but I think my BMS model needs that for clearing certain error conditions. Class T fuses...

Yes, charging a DC battery with DC power input is exactly what solar charge controllers do, and they must be the most common DC charging application, so we have plenty to choose from, with history and reviews. The charge controller wouldn't care or know whether the 48V comes from a PV panel or a...

Yes I had meant to post a reply to your thread but ran out of time this morning and this one came up in my search. As far as I know, you can't charge the two completely different (different voltage, maybe different chemistry) battery banks with one charge controller. Well, one charge controller...

I think you do need a charger between the two banks, not just a converter. I mentioned a few options in this post: https://diysolarforum.com/threads/sailboat-conversion-from-14-hp-diesel-to-10-kw-48v-electric-motor.18380/post-248247

On my boat, I've been using a 48V battery and a DC/DC converter that provides the 12V since 2012. But I once had an issue with the 48V bank which of course, meant I also had no 12V. No nav lights, no VHF, etc. So keeping a battery on the 12V side is a more robust design but leads to this...

Thanks! The weight should be in the specs. Well the cell weight. The other parts don't add much considering these cells are 62 kg, and the other parts are probably less than 5 kg, mostly in the thick bus bars I'm using. Larger cells would be heavier while the other parts don't get much...

My understanding is that compression does two things: keeps them in place to prevent stress on the terminal connections, and prevents them from bloating which shortens their life. I thought bloating was from high current, but mine did it a little during the top balance with a power supply that...

Batteries' BMS and motor controllers usually communicate via CANbus I think. My Orion Jr. 2 BMS and my Sevcon Gen4 motor controller both have customizable CAN communications. What I'd guess Epropulsion is talking about is something like the BMS determining a discharge limit in amps and telling...

I'm using the Orion Jr. 2 BMS. It has lots of options, but is pretty complex and pricey (compared to other options people here talk about. I don't think it's too expensive considering the cost and task of the batteries it's protecting, and I like the flexibility, support, and documentation)...

Just a note on 3M 5200: some boaters, myself included, will not use it anywhere, because it is absolutely permanent. Well, on a boat, isn't the keel permenantly attached? Maybe not, you might want to remove it for inspection and repair. For other parts that will be replaced every 2-4 decades...

Hi, a few more thoughts: I didn't see any mention of "precharge" or "pre-charge" which is a thing that one needs to know about when you have big inverters, powerful batteries, and a BMS. Since you are going to have a marine battery switch anyway, you can use that along with a resister or light...

Hello! You have a pretty boat and a nice project! You may want to think about the BMS protects the battery and how it interacts with your charge and discharge sources. Many people use charger/inverters in their stationary applications but separate chargers and inverters can be more robust...

Hi @BabylonFive, I don't have a lot to report. The boat will be launched in the middle of May so I haven't been in much of a hurry. But, I'm glad I ordered the cells earlier than I thought I'd have to - there were more details to work out and charging took longer than I thought. I have done...