Charging a Anker 20,000mAH battery pack with solar question?

ArmyChiefArmyChief Registered Users Posts: 18 ✭✭
Ladies & Gentleman,

I'm in the Army and will be purchasing an Anker (subject title incorrect name EDIT: fixed it for searches - 'Coot) rev 2 Astro Pro 2 20,000mAH battery pack for mainly USB device charging (tablets & phones). This company always appears to get good reviews, high quality build and more trustworthy specs. Lastly, it is one of the few that have a 12 VDC 2A input for charging (vs the more common 5 VDC 2A mini-USB charge ports). The A/C charger for this battery pack is rated at 12VDC 2A....and appears to be a normal walwart style charger. So, I'm assuming the BMS charging PCB is internal to the battery pack case.

I have a 20 watt foldable solar panel and want to use a MPPT charge controller to charge this battery pack. Wanting to keep this as small as possible, looking around the net...the Genasun product line (GV-5) appears to be perfect for the project. My questions are:

Based on the above assumption (someone please double check my assumption)...which Genasun model? (Lead acid or lithium)? I'm thinking go with the lithium 12 v model..since that unit doesn't constantly pulse current and I would not need the float and different stages the lead acid unit would attempt to apply.

Do I need to have the load output connected?...I only want to use this to charge the battery pack.

Lastly, do you think the DC charge input jack has voltage present all the time on the battery pack? IMF not, wouldn't that mean I would need to somehow trick the controller into charging?

Thanks all...I need some specialist in this fields advise :)

Comments

  • mike95490mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    Re: Charging a Antek 20,000mAH battery pack with solar question?

    for portable power, what about a regular automotive Jump Start pack? they often have a cigar lighter jack & a USB port? Most have a 15-25ah AGM battery inside.

    I don't know anything about Anker gear, sorry.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • BB.BB. Super Moderators, Administrators Posts: 32,921 admin
    Re: Charging a Antek 20,000mAH battery pack with solar question?

    I have a few of Anker's devices (2x USB 12 AH battery pack, 2x 5 port AC charger, 2 port high current DC car charger).

    All of them seem to work very well so far. The USB charger I used to recharge a Kindle Fire once (Amazon color tablet)--And it took quite a while and used much of the battery pack (I did not recharge the Fire back to 100%).

    Otherwise, they all seem to work very well so far. No problems, my daughter uses the USB battery and 5 port charger a lot too. The USB battery pack takes quite a while to recharge too (6-12 hours? off an AC charger).

    The Car Charger claims Input: DC 12-24V; Power: 24W.... For ~$10, I would get one or two and see if they can work on a standard Vmp~17.5 volt panel (possibly even take one apart to see what is inside and any voltage ratings of the components).

    They also have a folding 14 watt panel with 2x USB ports. Sort of tempting (I got a 7 watt Goal Zero that does charge my Android phone). This one seems to have a good price on Amazon right now. Don't know how reliable the panel is (a few folks here were not happy with the Goal Zero panel--I have not used it enough to know one way or the other). Flexible panels always seem to be a bit difficult to know if they will last in the field or not.

    You may also want to contact Anker directly for support (they seem to be pretty active in the Amazon comment system):

    Anker Team
    1-800-988-7973
    [email protected]
    Mon-Fri 9am to 5pm(pst)

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • ArmyChiefArmyChief Registered Users Posts: 18 ✭✭
    Re: Charging a Antek 20,000mAH battery pack with solar question?
    BB. wrote: »

    The Car Charger claims Input: DC 12-24V; Power: 24W.... For ~$10, I would get one or two and see if they can work on a standard Vmp~17.5 volt panel (possibly even take one apart to see what is inside and any voltage ratings of the components).

    They also have a folding 14 watt panel with 2x USB ports. Sort of tempting (I got a 7 watt Goal Zero that does charge my Android phone). This one seems to have a good price on Amazon right now. Don't know how reliable the panel is (a few folks here were not happy with the Goal Zero panel--I have not used it enough to know one way or the other). Flexible panels always seem to be a bit difficult to know if they will last in the field or not.

    You may also want to contact Anker directly for support (they seem to be pretty active in the Amazon comment system):

    Anker Team
    1-800-988-7973
    [email protected]
    Mon-Fri 9am to 5pm(pst)

    -Bill

    Bill,

    Appreciate the input. I already have a 20 watt solar panel, so purchasing another is not needed. On the car charger idea. I'm assuming with those specs, the charger is either a SMPS...and at 24W..it outputs 12VDC @ 2A. Or worse, it's just a 7812 regulator. Either one would not be as efficient to get maximum amperage out of my panel would they? My panel being a 20W panel, is already just slightly short of the maximum wattage needed to charge the battery pack (12VDC 2A)

    Oh, and I called their support....TWICE!.....dumber than a box a rocks....worse then my Radio Shack slogan.."you got questions, we got blank stares"

    Thanks
  • PNjunctionPNjunction Solar Expert Posts: 762 ✭✭✭
    Re: Charging a Anker 20,000mAH battery pack with solar question?

    I already do that, but with other brands, but check this out. Finding a 2A/12v dc adapter usually means old school bargain-bin linear supplies.

    Using a solar charge controller means that you'll be attaching it *directly* to a battery, and since the Anker already has an internal charger to take care of the internal lipo battery, using a charge controller prior to it's own charging circuits is not the best idea.

    Using a 5v usb input is actually a good thing in order to keep it simple, since most dc-dc converters are efficient switching supplies, and not linear anymore. These days, most modern ones have an input voltage of 12-24 volts, and this works in our favor as a replacement for the charge controller.

    What I'm suggesting is that if you can, change the model to one (or more) of the Astro E series (10000 / 13000 / 15000) models with 5v input. Why?

    You can now easily use a *modern* dc-dc converter directly attached to your 20 watt panel which in turn feeds the Anker. One model I use here often with my PowerFilm foldable panels to my Mophie / Samsung external packs is the Radio Shack Enercell micro-usb 1.5A / 5V vehicle adapter model CLA-428 #273-446. The key thing here is that it will accept 12-24 volts, so the 18v or so of the panel is no problem for the input to the adapter.

    All you need is a female cigarette lighter adapter hanging off your panel, attached to the RS 5v adapter, to your Anker w/5v usb input model.

    Simple! Note that your 20w panel will only provide just a little more than 1A anyway, the Anker models mentioned above only have a max 1.5a input, so this is a pretty close match. This is a totally off the shelf solution with no scrounging, soldering, or even too much engineering that works very well with the KISS approach.
  • ArmyChiefArmyChief Registered Users Posts: 18 ✭✭
    Re: Charging a Anker 20,000mAH battery pack with solar question?

    PN,

    Thanks for the input. There are a few issues with your solution.

    1. I really need as much stored power as possible in a portable package. The 20AH battery is really sweet.
    2. If I went with one of the smaller battery packs that require charging through the USB/microUSB..they as you stated, are typically limited to 5VDC @ 1-2 Amps...or 5-10 watts. This would not utilize my panels full potential..more importantly, it would take 5-6 hours to charge a 50 WH battery (10AH battery).

    So, the most efficient way to get more current out of my panel and have the flexibility to add more panels or use a larger panel to charge a larger battery (20AH vs 10AH) is to have a battery that charges at 12 VDC @ 2A (24 watts)... And use a MPPT device to get as close to my panel wattage.

    I have a programmable MPPT charger at home..the battery is being delivered today. Will be testing charging next week.

    Thanks
  • PNjunctionPNjunction Solar Expert Posts: 762 ✭✭✭
    Re: Charging a Anker 20,000mAH battery pack with solar question?

    You know the only constant for your panel is the wattage right? That 20 watt panel I'm assuming is a "nominal" 12v panel, that puts out about 18v open circuit. P/I*E shows that 20w / 18v = 1.1A max. In order to actually get more current from it, you'd have to rewire the panel so that it is say a 6V panel. In this case, 20w / 6v = 3.3a. But you don't want 6v. Yes you may get more from an mppt controller, but real world - what - another 200ma of current?

    Also note that external battery packs that are primarily designed for 5v usb output are rated in capacity at that voltage. Ie, the 10000mah Anker is 100 watts. 100w / 5v = 20ah. BUT now if you run stuff from the 12v output, that capacity goes down. 100w / 12v = 8.3ah. Something to keep in mind if you run stuff on the 12v output. Also note that this is not counting in a bit of efficiency loss.

    Other than that, I can't condone what you are doing from a safety standpoint. The Ankers are NOT your typical 12v Li-ion drop in packs with cell-level bms, which is what the Li-model Genasun's are designed for. And you know that the lead-based Genasuns will go up to 14.2v absorb. Not sure the Anker would tolerate that, if it worked at all. I'd consult Anker, and Bruce Schwab at Genasun and see how they feel about it.

    If you must forge ahead, PLEASE do so safely. Li-Cobalt or lipo batts usually found in external usb packs, unlike the larger Lifepo4 chemistry, are very intolerant of charging mistakes. The biggest issue is that charge controllers are designed to have a battery as the load, and not another charging circuit in between. On a similar level, a common beginner mistake is thinking that you can drive an inverter directly from a solar panel.

    This is part of the reason that if you are hung up on having 20ah at 5v output available, I'd pick up TWO of the 10ah Ankers, and use the simpler method of 5v usb automotive adapters for solar input, but it may be too late for that.

    I'd just hate to see you sacrifice safety most of all, and secondly the possibility of ruining an awesome Anker or Genasun product in a non-standard configuration.
  • ArmyChiefArmyChief Registered Users Posts: 18 ✭✭
    Re: Charging a Anker 20,000mAH battery pack with solar question?
    PNjunction wrote: »
    Other than that, I can't condone what you are doing from a safety standpoint. The Ankers are NOT your typical 12v Li-ion drop in packs with cell-level bms, which is what the Li-model Genasun's are designed for. And you know that the lead-based Genasuns will go up to 14.2v absorb. Not sure the Anker would tolerate that, if it worked at all. I'd consult Anker, and Bruce Schwab at Genasun and see how they feel about it.

    If you must forge ahead, PLEASE do so safely. Li-Cobalt or lipo batts usually found in external usb packs, unlike the larger Lifepo4 chemistry, are very intolerant of charging mistakes. The biggest issue is that charge controllers are designed to have a battery as the load, and not another charging circuit in between. On a similar level, a common beginner mistake is thinking that you can drive an inverter directly from a solar panel.

    This is part of the reason that if you are hung up on having 20ah at 5v output available, I'd pick up TWO of the 10ah Ankers, and use the simpler method of 5v usb automotive adapters for solar input, but it may be too late for that.

    I'd just hate to see you sacrifice safety most of all, and secondly the possibility of ruining an awesome Anker or Genasun product in a non-standard configuration.

    Thanks again for your I out..it helps bouncing this off someone else's head. I am unaware at what Anker has inside their battery pack. However, they must have an internal charging circuit. They only require 12 VDC @ 2A to charge. Temperature compensation and proper charging voltages I would assume are handled internally. So my thought was, as long as I make 12 VDC available, the internal charger will do the rest.

    Now, as you stated previously, no one makes a 12 VDC SMPS with 12-24 VDC input..the plentiful ones are 5VDC output. So, to charge this 20 AH battery, I need 12 VDC. Lastly, I plan on getting a larger panel. A MPPT looks like the most efficient way to maximize any panel to a 12 VDC Constant Voltage output.

    Now, looking at the Genasun model's I picked the Li version of 12.6 VDC...cause I did not want the lead acid Multi-stage charging...just 12.6 VDC constant voltage.

    So, in recap...if the battery has the charging mechanism inside (behind the coaxial DC input jack), and I must have an efficient constant voltage 12 VDC source with various DC inputs...am I missing something?

    Thanks
  • PNjunctionPNjunction Solar Expert Posts: 762 ✭✭✭
    Re: Charging a Anker 20,000mAH battery pack with solar question?
    ArmyChief wrote: »
    Now, looking at the Genasun model's I picked the Li version of 12.6 VDC...cause I did not want the lead acid Multi-stage charging...just 12.6 VDC constant voltage.

    Unfortunately, that LI controller will just stop once it reaches 12.6v, since Li batteries do not like to be trickle or float charged for extended periods of time. Even if you try to trick the Genasun, if it sees no voltage on the charging jack due to the Anker charger being protected by say a diode so as not to expose the consumer to the battery on that input jack, the Genasun won't even try with what it thinks is no battery connected. OR, it may ramp up quite quickly to 12.6v and just quit like it is supposed to do when connected to a fully charged LI battery.

    The Genasun or any charge controller, is an expensive wrong tool for the job.

    How about this - again it is a dc-dc converter, but it is NOT linear, and quite efficient. You'll have to supply your own wiring and make the voltage setting for 12v on your own. Search for this on Amazon:

    DROK DC Converter Voltage Regulator 8-32V to 9-46V 12/24V 150W Boost Step Up Power Supply Module

    Now THIS is more like it for the Anker that needs 12v / 2A input from your panels. Perhaps beef up your panel wattage to 30 or 40 watts total.

    If you really desire to use a Genasun controller, you'll need to use an actual battery, but then you'll need to provide your own wiring, FUSING, voltage monitoring, 12>5v usb adapters etc. A 10 to 12ah AGM would do nicely, (with appropriate Genasun model for lead/agm) perhaps in a "go-bag", but man, you have GOT to be safe and fuse everything.
  • ArmyChiefArmyChief Registered Users Posts: 18 ✭✭
    Re: Charging a Anker 20,000mAH battery pack with solar question?
    PNjunction wrote: »
    How about this - again it is a dc-dc converter, but it is NOT linear, and quite efficient. You'll have to supply your own wiring and make the voltage setting for 12v on your own. Search for this on Amazon:

    DROK DC Converter Voltage Regulator 8-32V to 9-46V 12/24V 150W Boost Step Up Power Supply Module

    Now THIS is more like it for the Anker that needs 12v / 2A input from your panels. Perhaps beef up your panel wattage to 30 or 40 watts total.

    If you really desire to use a Genasun controller, you'll need to use an actual battery, but then you'll need to provide your own wiring, FUSING, voltage monitoring, 12>5v usb adapters etc. A 10 to 12ah AGM would do nicely, (with appropriate Genasun model for lead/agm) perhaps in a "go-bag", but man, you have GOT to be safe and fuse everything.

    Excellent....appreciate all your input...I know some would have just got the wrong idea about my question/purpose. Your making sense and have valid arguments. For $16.00, I ordered the above referenced DC-DC power supply.

    I don't want carry a battery around....this is to be as portable/weight conscious as possible.

    Since I have your attention...is there anyway I could get a MPPT chip/device to work like the above DC-DC converter? Whereas, I could maximize a solar panels output (step down voltage, while stepping up amperage)? Basically a MPPT charger (no voltage present on the output..you could set the voltage instead. Maybe a programmable MPPT chip?

    Yes, maybe overkill.....but it keeps me busy

    Thanks,
  • BB.BB. Super Moderators, Administrators Posts: 32,921 admin
    Re: Charging a Anker 20,000mAH battery pack with solar question?

    You might look at these if you want to build your own MPPT based switch mode battery charger. From Texas Inst and another from Linear Tech:

    http://www.digikey.com/product-detai...9-1-ND/2352706
    http://www.digikey.com/product-detai...PBF-ND/2138757

    Some general information:

    http://www.digikey.com/us/en/techzon...y-charger.html
    ...The most basic approach for maintaining peak power point voltage (VMP) sets panel voltage to a constant voltage level, based on the manufacturer-specified open-circuit voltage (VOC). The rationale for this approach is based on the fundamental electrical characteristics of a solar panel. A typical solar panel comprises a series of cells that, electrically, are simply forward-biased p-n junctions. Consequently, engineers can approach solar cells as common p-n diodes -- with similar electrical characteristics including VOC and temperature coefficient (typically about 2 mV/°C).

    For a solar panel, VMP can be approximated as a fixed voltage below VOC, with a temperature coefficient at VMP essentially the same as that at VOC (and considered linear across normal environmental temperature ranges). Designing an efficient solar battery charger then becomes a matter of augmenting the battery protection capabilities mentioned above with a simple temperature-compensated resistor network designed to set panel voltage at VMP.

    The Texas Instruments bq24650 and Linear Technology LT3652 each offer MPPT based on this constant-voltage approach.

    For the TI bq24650, engineers can set the solar panel voltage to the peak power point using a resistor network across the device's VCC and MPPSET pins. The device's input voltage regulation circuitry responds when the input voltage drops as the solar panel loses the ability to provide the total power of the system. When the device senses that voltage on the MPPSET pin drops below 1.2 V, the IC maintains the input voltage by reducing the charge current. For MPPSET pin voltage below 1.2 V, the bq24650 stays in its input voltage regulation loop while the output current is zero. Engineers can also disable charging completely by pulling MPPSET below 75 mV.

    Along with a full range of battery protection capabilities, the bq24650 supports diverse battery chemistries including Li-Ion/Polymer, Lithium Phosphate, and lead-acid batteries. Based on the TI bq24650, the TI bq24650EVM Evaluation Module offers a complete solar power battery charger with multiple test points and jumpers for experimenting with this device.

    For the Linear Technology LT3652, engineers can program the peak power voltage for a solar panel by setting the required values in a resistor divider across the VIN and VIN_REG pins. Designed specifically for solar power battery charging, the device features multiple battery protection modes and supports diverse battery chemistries including Li-ion/Polymer, Lithium Phosphate, and NiMH/NiCd. The Linear DC1568A is a demonstration kit that provides a complete solar power battery charger based on the Linear LT3652.

    With their use of resistor networks for setting the fixed voltage for MPPT, both the TI and Linear devices enable engineers to employ a relatively simple approach for implementing temperature-compensated MPPT. Because the temperature coefficient for a typical solar panel is essentially linear, engineers can implement basic temperature compensation by augmenting the resistor network with a 3-terminal temperature sensor such as the National LM234...

    Many vendors will sell (or sometimes give away for free) development boards for their products. The chips have their limitations (such as not true MPPT--The chips do not track Vmp-temperature--You just set the Vmp value--May be good enough for your needs).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • ArmyChiefArmyChief Registered Users Posts: 18 ✭✭
    Re: Charging a Anker 20,000mAH battery pack with solar question?

    I found this..looks promising....better yet, they have an evaluation board!

    http://www.st.com/web/en/catalog/sense_power/FM142/CL1810/SC1517/PF250769
  • zonebluezoneblue Solar Expert Posts: 1,220 ✭✭✭✭
    Re: Charging a Anker 20,000mAH battery pack with solar question?

    Just some thinking out loud.

    I wonder what is inside the solar panel's in built 5v converter? Maybe take a look see what the chip is.

    We have a 10W amorphous panel out on the shed powering an electric fence energiser. It was thrown together one day in a hurry, with a 2 dollar adjustable buck converter set to 13.6V on a 5Ah AGM. It works but ive never studied it to see where on the IV curve it runs.

    For lead acid, theres a bit more to a charge controller than just voltage regulation. If you want to charge quickly using absorb and float set points is needed. For instance our system is on a days between bulk routine at present. On absorb days float occurs by 11am, on non abosrb days it takes until about 3pm until the charge acceptance flattens out.

    For lithium, none of that applies. Those portable battery packs are either lithium ion or lithium polymer. You can tell these apart by opening them, the former are cyllindrical, the latter boxish. Both technologys you charge with a CC/CV routine, and this is (or should be) all handled by the internal workings of the storage unit. Note that some degree of caution is healthy charging any lithium, keep an eye on it, place it on non flamable surface etc.

    If you are interested in a cheap DIY microcontroller mppt project take a gander at Julian Ilets youtube ramblings:
    http://www.youtube.com/playlist?list=PLjzGSu1yGFjWv4KeN-7TSYeQIcicM9Ghl
    using arduino to run a purturb and observe routine to find the vmp in real time.
    1.8kWp CSUN, 10kWh AGM, Midnite Classic 150, Outback VFX3024E,
    http://zoneblue.org/cms/page.php?view=off-grid-solar


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