Dual Battery Setup???

Discussion in 'Equipment' started by Rescue Wagon, Oct 6, 2012.

  1. daveburton

    daveburton Been here awhile

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    Thanks a lot that looks exactly like what I need (I think) and it appears to be small. Is it water proof or does it need to be mounted in some kind of case.

    dave
    #41
  2. URAL CT

    URAL CT Adventurer

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    Hi Dave...I don't think it needs to be mounted in a case. Mine is mounted on an (aftermarket) air cleaner unit on my Ural. Won't hurt to put silicone sealer where you might think water could get in. Just mount it under the seat or some place where it is shielded from direct water exposure. I've had mine through some rainstorms & seem not to be bothered by it. There's a small green LED light that is lit up when the two batteries are connected. It goes off when the main battery voltage goes below 12.6V. I kept my installation simple, there are other features though. Neat little unit...it has survived since '09.:D
    http://www.powerstream.com/battery-isolator-solid-state.htm
    #42
  3. BaldHead

    BaldHead Adventurer

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    I ride Aprilia ETV1000 Caponord. Very interested to build dual battery system but second battery (sitting inside some custom made alu box) will be quick and easy to remove (with the box) and to attach back on bike when needed (long and/or remote area trips, camp weekends).
    That alu box with second battery will have to be fitted somewhere close to my alu panniers, not sure yet where exactly. Thick wires fitted permanently on bike, connected to main battery on one side and to high power quick connectors (plugs ?) on other side. These connectors (Anderson type maybe ?) will be permanently fitted on back of bike, close to alu box with second battery and connected to it when second battery attached on bike. Thick wire (plus) fused 100A. I am thinking I should fit isolator inside the alu box (with second battery) but not sure yet. I can take the alu box with me inside/close to a tent to power light, laptops, communication etc...
    Also, second battery needs to be capable to work as main-starting battery in case normal starting battery fails (that is exactly what happened to me year ago in Flinders Ranges Nat. Park). This is my general concept but have lot of dilemmas...hope to find somebody more knowledgeable here...my questions are:
    -I would love to use lithium as second battery but is that correct to combine acid type starting battery with lithium type battery ?
    -Is that safe for rec/reg and generator to force them to do this job ? (recharging sometimes flat lithium battery AND provide power for bike including 2 x 45W H4 globes etc...) ?
    #43
  4. Syncrosimon

    Syncrosimon Numpty

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    Reading this thread with interest.

    I am about to wire up a second battery on my sons Yamaha 660Z Tenere.
    We are using a powerlet kit from Zen Overland same as this. It will allow power to enter the Givi Trekker Top Box with a quickly removable SAE connector with a fused connection to the battery.

    http://www.zenoverland.com/electrical/POW-USB-004-PTB-004-A1.html

    We are then thinking of having a second battery inside the top box wired in via a battery separator type relay. This should allow charging of the second battery when the engine is running, separate them when not. The Top Box is then filled with the things that need charging, and most importantly the whole top box will be removable to the tent, and provide power for lighting, and charging etc.

    I think this should work, and no need for an uprated generator as the battery won't be that big. (Not sure what size and type we will use)
    The top box will be compartmentalized with slots for all the individual items used during the day. IE the Jet Boil, water, day rations of food so these can be quickly accessed.

    what do you think?
    #44
  5. 2Fat2Pedal

    2Fat2Pedal Adventurer

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    I'm probably going to get on of these for solo, remote area riding.

    http://antigravitybatteries.com/microstartxp1/

    "The Micro-Start PPS (Personal Power Supply) is the world’s smallest Jump Starter and Personal Power Supply (only 6” x 2-7/8” x 1”). The built-in Extreme Power Lithium battery can hold a charge for up to a year and not only will it jump-start any car, truck, motorcycle or powersports vehicle mulitple times, but also provides hours of backup power to all of your electronic devices. Weighing less than a pound (14 oz.) and small enough to fit in your pocket..."
    #45
  6. SocalRob

    SocalRob Long timer

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    That is a very cool product.
    #46
  7. beemerphile

    beemerphile Long timer

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    #47
  8. Syncrosimon

    Syncrosimon Numpty

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    That battery pack is a neat idea. My youngest son uses lipo batteries in his rc truck, and those batteries pack a massive punch.

    The only problem that I see with its use in the wilderness is charging it. I can't see how you charge it other than at home on a wall plug. This would cause me problems for extended trips. The 12 v chargers are another $100 and end up with quite a bulky item.

    My sons lipo batteries have to be charged very carefully as you can wreck them with just one incorrect charge. If they go below volts they can die forever.
    #48
  9. ElJefeATX

    ElJefeATX Morally correct

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    [​IMG]

    Just saw this thread and I want to do an auxilliary battery set up for camping with a CPAP machine as well.

    Once I install this isolator, can the auxilliary battery be directly connected or does there need to be a charger, fuse or other circuitry between them?

    My plan would be to put the battery in a small pelican case to strap to the passenger peg bracket and use an SAE connector for quick connection and disconnection at camping time. I'll modify the case so that the SAE cable passes through and maybe even put a weatherproof cigarette connector into the case wall so I don't even have to open the case.

    Is that doable?

    Also do I need to stick with sealed lead acid or would a SHORAI LFX Lithium-Iron Powersports battery, 12Ah PbEq 12V eq, "A" polarity, Case Type 1 give me the deep cycling and 12 Ah capacity I need?
    #49
  10. _cy_

    _cy_ Long timer

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    LOTS of inaccurate information within this thread about li-ion batteries. there are several chemistries within the li-ion family. liCo (lithium cobal) and LiFePO4 are both properly called li-ion but are worlds apart for safety. the two operate at completely different voltages.

    LiCo batteries are inherently unstable and operate at very tight upper voltage limits to prevent overcharge possibly sending LiCo into thermal runaway (explosion). LiCo reaches full charge at 4.2V .. little as 3/4v over 4.2v can send LiCo into thermal runaway. so all devices that contain LiCo cells contain elaborate electronics (BMS) to monitor voltage to prevent overcharge conditions.

    advantage of LiCo is high energy density. this is why LiCo is commonly used in cell phones, laptops, electronic cigarettes, etc. this is also why you hear about laptops and cell phone catching on fire from time to time.

    scientist are constantly developing different battery chemistries in an attempt at increasing energy density and reducing liCo inherently volatile nature.

    now lets switch gears to LiFePO4 which is also correctly called Li-ion .. but with completely different operating voltages and safety characteristics. LiFePO4 batteries are inherently safe and tolarates wild overcharge abuse. while it's possible to overcharge 12v LiFePO4 .. it would take 30v to cause 12v LiFePO4 hot enough to melt. while possible, it's very difficult to abuse LiFePO4 bad enough to cause thermal runaway.

    there's been instances of 12v LiFePO4 getting charged at too high charge rates resulting in LiFePO4 batteries getting hot enough to melt. but out of thousands of 12v LiFePO4 batteries already installed .. there's not been one documented instance of a 12v motorcycle battery going into thermal runaway.

    most LiFePO4 mfg use misleading AH capacity information. pb/eq numbers mean little to nothing. what counts is actual amp hour. your Cpap machine uses actual amp hours to operate.

    for instance .. LFX12A1-BS12 is listed at 1.5lbs .. this means actual amp hour capacity is about 4-5 AH actual NOT 12AH ..

    you should check out Provent a new sleep apnea treatment using one way nose plugs to see if it works for you during camping.

    <iframe src="http://www.youtube.com/embed/HmfufUmxBbc?feature=player_detailpage&vq=highres" allowfullscreen="" frameborder="0" height="360" width="640"></iframe>

    <iframe width="640" height="360" src="//www.youtube.com/embed/bDgfl2XxyOk?feature=player_detailpage" frameborder="0" allowfullscreen></iframe>
    #50
  11. ElJefeATX

    ElJefeATX Morally correct

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    I appreciate all that information including the provent info. I don't think I'm going to be able to experiment with the provent before my 30 day camping trip comes up.

    So that leaves me back at square one with my question remaining, what type of battery should I get and will it work with the above isolator? For the record my CPAP manufacturer states that for my machine and my prescribed settings I should have a 13 Ah battery (that's with 50% safety margin). So I'm thinking I can get by with a 10 or 12. But which one?

    And can I wire it directly to that isolator?
    #51
  12. worwig

    worwig Long timer

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    Even the safer LiFePo batteries do not like to be deep cycled. Using them on a CPAP that does not have a low voltage cut off made for LiFePo is a bad idea.

    And LiFePo batteries intended as replacements for motorcycle batteries have obscure amp/hour ratings that are meaningless as CY pointed out. Notice that they call it amp/hour equivalent. It is NOT 12 Ah. Looking at the Shorai FAQ implies that they are overrating them by a factor of 3. So the 12Ah battery is really 4 Ah.

    For safety reasons, you want a fuse or fusible link if possible. The more likely the leads are to be touched/shorted, the more safety fusing you need. If it was a long lead, I would have fuses at both battery positives.

    Plus, I would avoid mixing chemistry. Do no parallel lead acid and LiFePo for example. Bad idea.
    #52
  13. bigdogbites

    bigdogbites n00b

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    Why not try one of these? Makes it very simple


    http://antigravitybatteries.com

    Attached Files:

    #53
  14. ElJefeATX

    ElJefeATX Morally correct

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    That won't work.

    Let's move on.
    #54
  15. _cy_

    _cy_ Long timer

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    +1 .. what an excellent overview!

    you really need to tell us which bike this is going on .. if you've got the room to modify your battery tray. my recommendation is to use a single large 20 AH actual 12v LiFePO4 battery from an electric bike. but only use the specific model that testing has been done on.

    cost is about $125 for a honest 20 AH 12v LiFePO4 .. I've done testing to verify actual AH of slightly over 19AH .. able to easily start your motorcycle down to 20f. weight is about 6.5lb .. main drawback is size. this is a Goldwing sized battery or Airhead sized battery tray .. largo .. details at beginning of battery testing thread .. link in sig

    [​IMG]
    #55
  16. ElJefeATX

    ElJefeATX Morally correct

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    I think we're headed in the right direction. Bike is a 2013 Triumph Tiger 800 XC.


    Here's the thing. It sounds like you're thinking along the lines of a single system main motorcycle battery. I want a portable battery I can charge while riding but can unplug and walk away with. That may have not been clear while talking about "dual systems".

    I would customize a pelican case to attach to the bike to hold the battery while riding. The bike has a powerlet with a 15 amp fuse exactly where needed. But the gap I need filled is from there to the aux battery to charge it WITH protection for the main motorcycle battery.

    And if the powerlet is a no-go we're back to direct connection to the bikes electrical system and the protections needed there.

    As an aside, here's a battery sold for my machine, but I think it's overpriced and they claim it requires charging from an AC source:

    [​IMG]

    CPAP battery pack and charger for 12V Resmed respiratory machine

    Product ID: HYLB-1256
    Item name: CPAP lithium battery pack for CPAP 12V Resmed S9, Resmed S8, Resmed VPAP Auto, Respironics Remstar, etc.
    Model: HYLB-1256, with connector of Cigarette lighter
    Nominal voltage: 14.8V
    Nominal capacity: 7800mAh
    Pack configuration: 4S3P
    Cell: Sanyo 18650 2600mAh
    Battery Dimension: 74x 69.2x 56mm
    Battery Weight: about 0.6kg
    Specified Charger: DC OUT 16.8V 2A
    Charger Weight: about 0.3kg
    #56
  17. _cy_

    _cy_ Long timer

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    nope .. it was pretty clear you want a dual battery system. but that adds all sorts of complexity to system. as stated above by worwig .. you cannot mix chemistries due to different voltages.

    you can easily mount one 20AH LiFePO4 inside your pelican case as your main battery. use full size cables to mains with quick disconnects ... simply disconnect from mains at night. this would be cheapest/best way to go. assuming letting Tiger sit dead with no power will not effect computer next morning. a 20AH LiFePO4 will easily run your cpap at night with more than enough reserve AH capacity to start next morning. especially when camping during warm weather.

    plug back in next day and let bike charge your LiFePO4 back up .. one advantage is LiFePO4 will charge back to about 85% levels within 15 minutes or so .. but absorption phase of charge to fully top up takes much longer.

    another option is to install the proper LiFePO4 in Tiger's battery tray .. then hook second battery in parallel. provided both batteries are same voltage/chemistries .. take extra care to prevent grounding as li-ion batteries discharge at extremely high rates .. producing heat easily equal to arc welding.

    Resmed OEM batteries are Lithium Cobalt (LiCo) which are inherently dangerous and need special 120v chargers/BMS to make sure batteries don't get overcharged. little as 1v over the 4.2v max charge per cell could send batteries into thermal runaway (explosion) most dangerous part of using LiCo cells occurs during charging. only charge in a safe fireproof location .. never unsupervised.

    that Resmed OEM LiCo 7.8AH battery pack is NOT a little one .. personally would not want something like that near me sleeping. using LiFePO4 battery is much safer!!!

    <iframe src="http://www.youtube.com/embed/ixIOEPnsgbI?feature=player_detailpage&vq=highres" allowfullscreen="" frameborder="0" height="360" width="640"></iframe>
    #57
  18. ElJefeATX

    ElJefeATX Morally correct

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    OK this one is not gong to happen.

    This would be acceptable, but is starting to get pricey.

    So I'm not so worried about weight. What about an 8ish pound 12 Ah SLA/AGM or such? Can we go back to that with an isolator with my stock, OEM battery?

    I always wondered why there were so many threads about this with no solutions. Now I understand why.
    #58
  19. _cy_

    _cy_ Long timer

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    don't know about other threads so can't comment .. but a solution is not that difficult. and yes going with 2x LiFePO4 with enough actual AH in Shorai or EarthX or AntiGravity will be very $$$ expensive. that's why the electric vehicle $125 ..12v LiFePO4 was suggested

    if you are not concerned with weight .. there's no reason why you cannot use a second identical chemistry AGM battery in parallel. but then charging times for AGM becomes an issue on days with short rides.

    are you camping out every night for 30 days with no access to 120v? how far are you traveling each day?

    you've rejected the most elegant/simplest solution of using one large 20AH (actual) LiFePO4 with more than enough reserve capacity to run your cpap and operate Tiger. costs is about $125 with weight about 6.5lb .. quick charge times ..

    fyi .. it's easy to verify state of charge with LiFePO4 when putting bike away for the night. 13.3v (90%) would indicate full charge status with enough reserve AH capacity to operate. what about parking your bike next to tent then run an extension cord?

    what ever solution you go with .. sure hope you've got enough time to test system out before leaving.
    #59
  20. worwig

    worwig Long timer

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    I would think you would want to get this system. Charge it from AC when possible. Or charge it from an inverter connected to the bike when traveling. The charger is 16.8V 2A, or less than 50 watts. So a tiny little inverter will handle it.
    Then you have no question about how well it will work.

    Notice also that this system is less than 8Ah. Not sure you need to go much larger for a home grown setup. (other than to compensate to the BS amp/hour specs like from Shorai)
    #60