Hi Chris,
I have worked with many different kinds of batteries over the years, and by far Northstar makes the best battery when you consider all of the characteristics of this battery.
The batteries are put through some grueling tests by Northstar including taking them up to 20 volts or so for extended periods of time. Even under the most punishing of tests, these batteries have zero chance of catastrophic failure. This is the big reason that I endorse these batteries. No other battery makes this claim.
The one issue with the Northstar is they are vulnerable to over charging and most chargers can over charge these batteries. These are not high performance AGM batteries that typically look for voltages of 14.7 volts. These batteries charge better at 14.3 to 14.4 volts and certainly not more than 14.5 volts. Northstar recommends charging voltages of between 14.3 and 14.7 volts. If you use the high voltage, and anything gets out of balance, then you would drive one battery over the 14.7 volt threshold and this would be detrimental to that batteries health.
Like any battery in a string, these batteries also need to be balanced from time to time. They need less battery balancing than any other battery though and may need none at all for many years. But at some point they will need to be balanced if you want long life out of them. So keep an eye on your voltages and make sure they are all within .05 of a volt.
Absorption charging is better if truncated by current at 2% of battery capacity or about 4 amps going into the battery. Most chargers do not discern whether the charge goes into the battery or into a load somewhere so its important to get that right. If you truncate on time alone, then absorption time should be less if you charge at higher voltage and more if you charge at lower voltages. I would not want to keep them at absorption for more than 2 or 3 hours at most. Most chargers will time out of absorption at 4 hours. Absorption time is is also a function of how powerful the charger is.
To figure out the best absorption time, charge the batteries up using current algorithm and then let them wait with no load on them for about a day and then measure the voltages. The resting voltage after a day or so on new Northstars should be about 12.85 volts. If lower than that, then increase absorption time. If higher, then decrease.
I have developed a balancing charger for these batteries. You may contact me off list if you want all the details.
The biggest advice I have for you is do not be in a hurry to get them. If you go through a supplier, they will often mix and match the batteries from different time stamps. Tell your battery supplier you want all of your batteries from the same date stamp and you do not mind waiting for the next batch to be made. 48 volt applications are far different from 12 volt applications and time of manufacture and environment both contribute to having a battery stay in balance. I would also mount these batteries all in the same orientation with the same heat environment. All batteries in a string should be dealt with identically for the very longest of battery life.
I put 8 of these batteries on my boat: they we're all made within 10 minutes of each other. They stamp the date and time right on the battery. If you wait, you also get the benefit that the batteries are fresher. The closer these batteries are in time and environment, the less battery balancing is required. Same day, and you may need no balancing at all for 5 years of so.
These batteries are designed to last 10 years and at one point in time the website said 15 years if I recall correctly. These batteries will last a long, long time. You would replace any other battery probably twice, within the life of a Northstar if correctly charged.
If you want to have 8 batteries at 48 volts, its better in two strings, though it is possible to parallel at the battery level. You may contact me for full advice on these batteries, how to buy, and install them for the longest life possible.
The SMS 480 is the same battery as the NSB 210 SMS stands for Stereo, Marine Specialty NSB stands for North Star Blue.
I personally would not go the LIPO route as there are issues over time with LIPO batteries. Every connection matters and if the BMS fails you could be looking at some awful problems aboard a boat.
Northstar batteries will cycle 500 times or so down to 20 percent so for the same weight, they get about twice the cycling power of a standard AGM or lead battery. They will also charge faster than any other lead battery. And absorption times are less than other batteries.
When compared to any other Lead battery, Northstar Blue Plus is light years ahead in their technology. They are far more efficient, and last far longer than anything on the market, plus they are the safest battery you can buy. Look after them, and they will look after you.
James
James Lambden
The Electric Propeller Company
625C East Haley Street,
Santa Barbara, CA
93103
805 455 8444
james@electroprop.com
www.electroprop.com
Hello group,
I'm shopping for new batteries for my sailboat. I currently have 16 Trojan T-145s in series parallel. 520aH total at 48 V. They have served me well and will soon be 6 years in service. I'm wanting something in this capacity, but in a more maintenance free design. I have been reading the various battery postings from this group with interest. I have not totally ruled out LifePO4, but I have concerns with BMS failure, charger integration and, of course the initial cost of a system in the capacity that I require. I forgot to mention, my boat is a Morgan Out Island 41. With my experience with this boat and the smaller size of my generator, I don't want to reduce capacity much. The other battery that I am considering is the NorthStar NSB 210FT BLUE+. They are essentially an AGM battery with carbon added to allow it to better tolerate partial states of charge (PSOC). One thing that I've noticed with my T-145s is the incredibly long absorption time while at anchor. Most time I just give up trying to get to 100% SOC, which I understand is not good for FLA batteries. 8 of these NorthStar 12 volt batteries (400 aH total) would cost less than half of a comparable capacity LifePO4 (CALB) bank with BMS. I'd like to get some feedback/opinion as to the suitability of these NorthStar batteries for this application, and maybe someone can give me more confidence to make the LifePO4 plunge. Thanks for any help this group can offer.
Kind Regards,
Chris Hudson
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