Bobolink PowerWings lithium batteries for off grid — get the facts
Includes Bobolink's exclusive monitoring system! Now with custom cabling and a new BMS option for larger packs -- even better, safer, easier use!
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The PowerWing uses the same chemistry, NMC, as the PowerWall from Tesla. They are in a different format. While Tesla uses cylindrical cells, LG Chem uses pouches.
Top PowerWing benefits
PowerWings means using large draw appliances like fridges, dishwashers, induction cooktops, air conditioning all becomes normal. Sure, there are folks with lead acid packs who use those devices. But they have huge battery packs. So they draw only a little bit from each battery to feed a large load. With lithium you can draw a huge amount from a small battery, no worries.
The basic advantages of the lithium PowerWing are:
- far better charge efficiency. This means the electrons coming through your panels easily flow into your solar storage pack.
- much higher discharge efficiency. This is the most efficient chemistry available. Which means your battery pack feeds loads not creates heat.
- much longer lifespan. Even the best lead acid is 2500 cycles. PowerWings, if used politely, will see 5,000 cycles or more.
- best depth of discharge (dod). For longest life; use 50% for the best tubular lead acid, 20-30% for lesser batteries VS 80% for NMC lithium.
- much deeper discharge. This means you need a much smaller battery. Typically 1/2 or 1/3 the amp hour rating of a lead acid pack.
- which means much smaller size. This means they take up less space. When you look at your $/ft build cost. Its nice to know your electrical supply won’t cost 3x as much for installation space. And with the lighter weight, the modules weigh only 42lbs/18kg, anyone can move and install the system.
- does not need to be vented. This means you don’t have to put holes in your house or worry about fumes. Both for your health and the health of your system.
PowerWings modules offer:
- 48v 47a 2.25 kwh per module
- superior 90% round trip efficiency
- 80% dod with up to 5,000 cycles
- use of high surge/drain appliances
- efficiency makes your solar system 20% more powerful
- integrated monitoring for all cells
- cells are tested and quality verified
- all cells are balanced
- require almost no maintenance
- no off gassing
- ideal for off grid solar storage
- ideal for seasonal solar storage
- exclusive wiring harness and active cell balancing. No one else has this! Developed by the BobolinkSolar crew!
Built exclusively with LG Chem modules from Volt automobiles, our modules come in different year classes. All our cells are A grade. But newer year cells will have slightly higher capacity. This is reflected in the price. Remember. Only PowerWings come with our exclusive cell monitoring kit. And are tested and ascertained A Grade.
7 in stock (more on the way)
2.125 kw per module. $650.
4.25 kw (2 modules) for $1,250
Nissan Leaf modules. $/kw. SOLD OUT.
Now available as an assembled 56v pack! 1250 per 3700w pack module. Packs can be paralleled up to desired size.
These cells have some advantages over Volt cells. One: they are a bit bigger. 66ah compared to 47ah. Two: They can be charged down to -10C vs the Volts 5C. Three: The 8v modules can be configured to 56v. Useful for those with older solar equipment looking to update their battery banks.
What puts Bobolink PowerWings above the rest?
One: Tested. We guarantee that your PowerWing module is Grade A. Six month full warranty. 7 year pro rated. You must provide monitoring data periodically. It’s part of our cooperative development team approach. Become part of the team!
Two: They come with our exclusive cell harnesses and active cell balancing: Plus monitor. Only PowerWings monitor every cell. You know how much power you have at hand. No guessing with PowerWings. Just safe powerful solar storage.
Three: Cost and availability. These packs are available now. Today. This very moment. And they cost 1/3 to 1/2 the “fancy brand” price. Why wait years for an overly expensive solution when you can build it right today.
“Upgraded from a 14kwh lead acid system to a 12kwh PowerWing from Bobolinksolar in July 2016. After 6 months I’ve seen no cell drift. 90%+ round trip efficiency. Compared to my old lead acid. Like getting a 20% bigger solar system for free. Plus no maintenance. Lights no longer flicker when the fridge comes on. Haven’t run the generator since installing. Using double the power daily. Astounding.” — Mr. C.
UPDATE: “Pack still performing above expectation. Still haven’t run the generator. No cell drift. Thanks for the free harness upgrade. Nice to have for the long term. Excellent service.” Mr. C, fall 2017.
The time is now
How to use
Essentially when sizing lithium PowerWings look at 1/3 to 1/2 the lead acid (fla) sizing requirement. This is because lithium can discharge to 80% instead of 20 to 50%. And at 80% lithium has 2 to 4x the lifespan of lead.
There are many lead acid batteries. A basic FLA has 500 discharges at 50% dod. That’s going to last less than 1/10th the time of a lithium pack discharged to 80%. Still. Some of the new lead acid with fancy materials batteries last longer. Top quality FLA can do surprisingly well. But no lead acid pack is as efficient charging/discharging compared to lithium. Nor do they easily handle high discharge rates. Lithium is, today, the best solar storage battery.
For longest life you charge the cells to 90% capacity and discharge to 20%. The Powerwings recommendation is that you discharge to 40v and charge to 48v max with our modules.
PowerWings are cold temperature sensitive. While unlike lead they don’t lose capacity at that alarming lead rate. In very cold weather recharging you risk “plating” the anode. For this reason lithium should always be charged at above 5C. You can discharge to -25c but warm the battery before charging.
(Note the Leaf battery can be used to -20 and warmed to -10 for charging).
So if you get to the cottage on a winter’s morn. Its okay to turn on the power. But heat your batteries up before beginning charging.
Lithium is less hot weather sensitive than lead. Lead acid decays at double the rate at 35C. With lithium you can go to 45C with only a slight uptick in degradation. But we recommend 35C as the top value.
PowerWings last longer. Work harder. Perform better.
Technical data: Volt derived packs
These highest quality LG Chem modules are comprised of 47Ah cells arranged in a 3p12s configuration. They are rated at 350 amps peak. Our PowerWings solar storage are happy being air cooled and heated. All modules have an integrated connector with cell level connectivity and integrated thermistors.
Height: 11.0 Inches / 28 cm
Width: 9.55 Inches / 24.5 cm
Length: 9.2 Inches / 23.5 cm
Weight: 42 Pounds / 18.6 kg
Bolt Size: M6
Voltage nominal: 3.85V/Cell, 46.2V/Module
Charge voltage cut-off: 4.03V/Cell, 48.3V/Module*
Discharging cut-off: 3.4/Cell, 41V/Module*
Maximum Discharging Current (10 sec.): 350 Amps. 200a continuous.
Warranty Period: One to 5 years (depending on monitoring/use.)
Note: LG Chem improved the chemistry every year. Starting in 2013 they have better temperature tolerance. 2013/14 cell voltage moves to 3.85. 2015 has 2 amp greater storage. The batteries can be used down to -25C. But should only be charged between 5 and 45C.
- Max charge voltage is 48.6 for longest life. 49.2 for more power but shorter life. Exceeding 50.4 not recommended. Low voltage cutoff should be 40v for longest life. Below 38.4 not recommended. This gives you about 80% of the batteries capacity and should ensure you get 5,000+ cycles. In a solar application that should be 14 years.
These batteries may not be available in all jurisdictions. Please consider your use and manage responsibly.