Lithium IRON Phosphate battery technology – LiFePo4 – looks to be in production world wide and seems to be a safer electrical storage technology than the previous Lithium Ion battery chemistry was for use on a cruising sail boat. We looked at sources and costs and shipping charges and and and… We got a note from friends who said they were driving down from San Diego CA USA to Guaymas Sonora MX and and and we jumped at the opportunity to have batteries shipped to them in San Diego and we will figure out how to get them from Guaymas to where ever we are… Our 4 year old 6 volt GC2 220 Amp hour batteries (4 in the house bank) are showing their age …
There are many cost comparisons on the web for lead acid vs. AGM vo Gel vs LiFePo4 vs vs vs, sufuce it to say we picked the LiFePo4’s …
The LiFePo4 batteries are interesting in that they seem to have conquered the Lithium Ion battery problems of overheating.toxicity, hazardous waste, fire and etc.
The ones we ordered are advertised as “drop-in replacement” for lead acid batteries. Having studied the web info, bot all of it I am sure, we hope our installation wcan be relatively clean fairly low impact to the boat systems in place.
I’ll go over our planned changes, which we hope to keep to a minimum. Thinking that if you have to spend a fortune to implement the lithium batteries that them become way less attractive! And I’ve just put interesting links found investigating making our house bank a lithium iron phosphate battery bank…
- LiFePo4 batteries – 4 each 100 Ah 12v LiFePo4 “drop in: batteries $870 ea,
- Battery Monitor – replace the NASA BM-1 Compact with a Victron BM-702 $218
- Add Diode Battery Isolator – A battery isolator should reduce the charge voltages passing through it bu 0.4 to volts effectively reducing out charge voltages from 14.4 max to 13.4/14.0 max – Sure Power 1202-D Marine Battery Isolator 120 Amp max. We will run both the alternator output and the shore power charger through this… $65
- Solar Charge controller – Replace our e20 from eMarine Inc with a 4215BN EP Tracer 40A 12V 24V MPPT Solar charger Controller regulator with MT50. It has user programmable charge voltage settings $210
- We are also getting some temperature monitor equipment to keep an eye on the alternator temp while charging and the battery bank temperature.
- I also saw some Amp/Volt/Watt hour meters with shunt for $17 each and had to see how they work! Toy time for this one… We will put one in system somewhere to access their value!
- We may add a solar panel. We think we are a little under served by the two 135 watt kyocera panels in the current syste, Thinking of adding a 100 or 150 watt panel…
“Three little pigs” – you say!
Ya, “the three little pigs”, what do I mean? Our major problems in our conversion from Lead Acid batteries to Lithium batteries looked to be the three charging systems we use on-board s/v Hajime: 1) solar panels, 2) the diesel motor alternator, and 3) the shore power battery charger… We hope to slaughter the pigs as follows:
Some new equipment needs for s/v Hajime:
As an overall control tool, we have ordered a Victron MC-702S. It is a gauge for being able to count Amp Hours in and out… The 702 also gives us info on an aux. or starter battery and programmability to control relays based on state of charge limits (SOC) if we feel it necessary in the future…
Seems our “NASA BM-1 Compact” is a bit crude for using with a LiFePo4 bank, it has no programmable features and no re-set-able functions :
We are changing our solar controller for the photo voltaic panels which we can program voltages for the charge phases. We found this 4215BN on ebay which is user programmable on all three phases between 9 and 16 volts…
We are thinking of adding a third PV panel to our two panel system:
Size 26.25 x 1.88 x 59″ of our existing two Kyocera 135 W panels came with the Hybrid Wind/Solar kit from eMarine Inc. purchased in 2010… and we are looking at adding a third panel when we can…: more later
We need to manage/track the alternator charge cycle so we don’t overheat our 120 AMP Beta 30 OEM 120 Amp internally regulated alternator… We do need to get the output voltage limited to <=14.0 volts … Our studies conclude that a diode based charge splitter will reduce the voltage output of an alternator by 0.4 to 0.9 volts. Using this we hope to reduce the output voltage of both the alternator and the shore power charger…
Our alternator a 120 Amp OEM from Beta Marine supplied on our Beta 30 Marine diesel engine looks to top out at 14.4 volts output, so maybe the splitter/diode (old tech) is just the ticket to reduce our alternator output voltage to around 14.0 volts max. without trying to use an external voltage regulator… TWT (time will tell)
We plan to monitor the temperature of the system components ie. alternator and batteries so we found a temperature gauge and type K thermocouples to put in-place to help us monitor, we had a infrared gun type and have added thermocouple type…
We may need to add similar process controls for our shore charging and get a procedure in place prior to replacing charger with better suited equipment but to begin with we will run our existing charger through the diode based battery splitter and see if it reduces voltage to acceptable levels!
New Equipment : Bayite DC 100 AMP meter and Victron BMV-702s and 100Ah LiFePo4’s. The “Bayite DC100 meter” is a toy for us to see how a well a $17 gauge will work in this environment … A remote temperature gauge and thermocouples, A programmable solar charge controller and a cahge splitter 120 Amp for alternator and battery charger output voltage reduction…
Summary (for now):
I have looked and looked to see if anyone has been dumb enough to to try to put the “drop in” 100 amp hour into a 400 amp hour house bank by building a parallel connected battery bank. No one has been brave enough to stand up and say “I tried”.
Well, we are going to try and in order to only risk half of out battery investment in the beginning, we are looking to try two of the 100 Ah batteries in parallel and if all goes well we may add the other two we purchased to the house bank if needed!
General Info, parts info etc…
Thanks Alan, a post link:
There is a blog/web page by Compass Marine takes issue with the idea of “drop in replacements” and we are taking his concerns and warnings to heart while we implement the energy storage system into s/v Hajime: Here is an ir-reverent rant from Compass Marine (http://www.marinehowto.com/) on Pbase.com, it is really rather comprehensive and in my opinion well done, Thanks Compass Marine! Could title an entire blog, “Oh my, what have we gotten into?” or maybe “Ha Jim e! it’s your LiFePo4!” …:
Liked this info from above blog, hope my quoting the below text is taken as a compliment and not a copyright infringement:
Cruisers forum topic, at this writing 326 pages and growing, a topic on using LiFePo4’s as a house bank. Kinda WOW for using the web as a crowd sourced wealth of information… taking it as every web thing with a grain of salt …
Here is a fellow who has pondered the problem some, maybe too much “some”:
A links for charging recommendations for the LiFePo4’s:
Here is link to the alibaba site for the EWT manufacturer and the info (what there is) on the 12v 100Ah LiFePo4 battery module we are getting:
Here is link to site selling the BMS (Battery Management System) shown in the photo on the above site, Model Number is PCM-L04S50-674, looks like the is the BMS in our EWT 100 Ah batteries:
And a link to purchasing the BMS via alibaba at $0.6 USD per unit???:
BMS Specifications from above site:
|1||Voltage||Charging voltage||DC 14.6VCC/CV
|Balance voltage for single cell||3.65V±0.025V||4.20V±0.025V|
|2||Current||Balance current for single cell||36/72±10mA||42/84±10mA|
|Current consumption for single cell||≤20μA||≤20μA|
|Max. continuous charging current||50A||50A|
|Max. cont. discharging current||50A||50A|
|Over charge detection voltage||3.9V±0.025V (optional)||4.35±0.025V (optional)|
|Over charge detection delay time||0.5-2.0S||0.5-2.0S|
|Over charge release voltage||3.8±0.025V||4.15 ±0.05V|
|Over discharge detection voltage||2.0±0.05V
|Over discharge detection delay time||100~300mS||100~300mS|
|Over discharge release voltage||1.9±0.1V||3.1±0.1V|
|Over current detection voltage||0.06~0.6V||0.06~0.6V|
|Over current detection current||80~500A (can adjust)||80~500A (can adjust)|
|Detection delay time||5-20ms||5-20ms|
|Release condition||Cut load,||Cut load,|
|Detection condition||Exterior short circuit|
|Detection delay time||200～500us|
|Release condition||charge up|
|8||Temperature||Operating Temperature Range||-40～+85℃|
|Storage Temperature Range||-40～+125℃|
Description:- Alternators Iskra Letrika
Here are some interesting LINKS:
http://www.bowest.com.au/library/theorems.html woohoo techie’s