I risk diverting this thread but I'm getting so much great information...
Thanks BobJ !
>> send me an e-mail: BobsailsSF at yahoo
I did. Thanks for the continued assistance, on all threads, it is much appreciated.
>> despite the goofy magnetic pen to program them, they've been fine.
I think your Balmar unit and my MC-614 are similar and I too have that goofy programming system. Balmar claims its to avoid an intrusion point. I called Balmar and the new MC-618 for example allows smartphone programming except you also need to buy their shunt and their battery monitor and then wire all that up in addition to the shunt and battery monitor that you surely already have (Victron in my case). That just seems plain daft design engineering to me.
>> I've not been able to get the battery temperature sensor to work
I have a battery temperature sensor for the Victron monitor and I never see anything much happening at the battery with the charging currents I presently use. I *think* though have yet to confirm, thats its all about the alternator temperature. I will find out.
>> It's Balmar's 100A unit and I've never seen more than 40A out of it.
I will be interested to see what I can get out of my 170A unit if I tried.
>> I think I'm using a lot less juice than you are and the batteries just never get that low.
I am doing worst-case analysis or trying to, but I'm still surprised how all the devices add up, how much you forget (like charging the handhelds), and how poor solar is. I do need not only modes for use but modes for what happens when things fail, such as losing one solar panel or a battery. I need to construct a "vital systems only" mode for example.
and thanks Solosailor!
>> With a 170Ah Balmar you should be able to get 100-120A without overheating.
I will find out. I think I have a big engine and big alternator in a small boat. I do have a way to extract some heat, but not sure I want to build a power station inside the boat. We'll see.
>> Do you have a serpentine belt kit?
Yes. I have a 410J10 with the Balmar red and blue pulleys. I am struggling to get just the right belt tension which I gather is key. I do have a Belt Buddy. I just bought a couple of gauges, the Gates Krikit and the Amazon standard 10 lb push gauge. Never used one before but that might help figure out what is going on in some quantitative way instead of the qualitative look and feel which is what I'm doing now.
>> Also you talk about a LiPO, which would be a huge no no.... but I imagine you mean LFP (iron phosphate).
Yes. I have a Relion RB300 Lithium Deep Cycle Battery LiFePO4 (or LPF) main battery. My bad. I was researching battery fires and just typed LIPO. Fire is one of my concerns with these batteries. I think Brian or David told me one of the SSS members works with fire issues for DoD and I looked at some of the research on Li battery chemistry fire suppression but not sure there's much you can do. I have read
https://www.coastalclimatecontrol.com/images/PDF/ReLiON/Relion_SafetyLithiumBattery_Coastal_2.pdf carefully (and cant find this at the Relion site). I have a ceramic firewall but what good is that going to do.
>> what is your 2nd battery for the house as I recall the rule wants 2x batteries.
Yes. A 100Ah Relion, same chemistry, same everything as main, different capacity. Starter battery can be paralleled (combined) to the main. I have a Sterling Pro Batt Ultra BB1230 between the two batteries as the charger on the Victron MultiPlus Compact 2000 inverter is a bit too small. I have never seen the issue of throwing the Blue Sea battery switch to combine two big batteries discussed in detail. I do see Relion specifies 50mV (
https://relionbattery.com/blog/how-to-successfully-charge-relion-batteries) which is not going to be practical in the emergency situation for which you would typically use combine. I have tried combining at 500mV separation and it worked, just because I cant live with the uncertainty that it might not. What are you going to do? bleed the high battery? I do have a third completely separate rechargeable battery for emergency system use and I may get a fourth. I do worry about the complete reliance on someone's BMS design. I have this weird feeling that relying on products that have a niche market (such as marine where B&G would be an example) is much worse than relying on a mass-market product (like Li battery technology). I'd rather not rely on anyone, but if I have to risk assess I think thats how I place my relative worries.
>> Do you know that the 300Ah Relion only recommends a 10-50A charge (their BMS is the limiting factor) with a MAXIMUM of 100A?
Yes. Those figures are front and center at
https://relionbattery.com/products/lithium/rb300 for example and the same values for the 100Ah battery. The Relion FAQ does say 1C (
https://relionbattery.com/resource-center/support/faqs). Some of their documentation says the lower of 100A and 1C. Also watch
https://youtu.be/oHJ3UdQLnOs?t=78 (at that time point). I haven't sorted all this out with them yet. LMK if you have! I don't think I would want to go above 100A charge current as that puts me at a 1.3kW dissipation (assuming a 50% efficiency) in the engine compartment. Does that sound right?
>> If you have two of those batteries your max charge rate for the pair should be 100A.
I have to think about that. You might think you can charge at a maximum of 200A on combine, but who knows which battery wins and in any case I wouldn't want to do that. Again, if you have got into this with Relion LMK. You are right and it may be worse, the conservative charge current for either one or two batteries in parallel would be 50A. I currently start at about 70A and reduce to 40A. After I do some more work on what my alternator is doing, I will call Relion and see what they say.
>> I would not go offshore with that battery with such a limited internal BMS.
Please step on my toes. Thats how I learn. I am learning so much from the SSS Forum and a lot from just this thread and especially from you! Thanks!! I have what I have at this point and have to learn to live with the problems and limitations of what I have. My boat is small enough that it would be really hard to swap out the current electrical system, especially the batteries, and honestly I'm not sure how much better I could make it. I do absolutely worry about losing one and then both batteries. If you had a blank cheque what would you do?
>> Also, how are you charging your starting battery....?
The Sterling. Another wonky programming system.
… and thanks again to everyone. Keep the great comments coming!
