need to replace my backup battery

Discussion in 'General Technical Questions and Answers' started by VE3KNT, Sep 12, 2019.

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  1. VE3KNT

    VE3KNT Ham Member QRZ Page

    My backup battery, that came out of a Honda I happily scrapped about 5 or 6 years ago had gone over to the dark side of the force and I need a replacement.
    Live out in the boonies, my choices are limited with out a long drive (and I'm not in good health to enjoy long drives these days)

    Here are the two contenders that aren't too far away: The 1st one has a lot more capacity, but the second is sealed and non spillable. I'm leaving toward he high capacity one. it with be kept in a plastic marine battery box that has a vented cover in my living room. and will be charged and switched but a "LowLoss PWRgate" the little blue one, *not* the Westmount type. I tried contacting the makes and he doesn't respond to support emails. There's frequent power failures here, usually 3 hour or so long. So far 3 in the the last month.
    It will be powering a Yaesu FT450, and/or uniden scanner, LED light, maybe CB or short wave. but not all at once of course..

    So looking for some thought about these. the next option is drive in to the city for something like a 32AH sealed deep cycle fore $114(Cnd of course)
  2. N8AFT

    N8AFT Ham Member QRZ Page

    Of course any Lead Acid battery will fume when charging or during a heavy current draw discharge.
    Not sure I'd be too worried about a marine grade cover... I'd be Very concerned about having that battery venting inside a living area.
    Hydrogen Gas and Oxygen is what the battery vents, this is vy explosive stuff. Ever seen a 12v car battery explode? Not nice.
    Do what you can to relocate said battery outside and run cables to the shack from there.
    Your sinuses will be better off but I'm sure whoever has your homeowner's insurance policy will think more highly of you and Amateur Radio.
    There are a number of vy fine battery shoppes on-line, some even deliver free of charge.
    My battery is an FAA approved deep cycle AGM 100a from Lifline battery. It is vertually Vent Less and can even be mounted inverted.
    I keep it on a Tripp-Lite 12v 25a power supply round the clock 24/7. The supply voltage is 13.9VDC. ANY battery only draws current as needed.
    An isloation diode would be recommended if the supply you are planning to use does not already have one.
    Forward bias a 30 ampere diode in series with the positive lead.
    A 33AH deep cycle will work well. Transmit power may need to be lowered to conserve charge.
    I run a 33AH AGM deep with 2 100 watt solar panels when portable CW QRO 100w.
    My battery stays up ok with sunlight of course.
    Look up Impact Battery on-line. He has 33AH sealed AGM deep cycles for $175 DELIVERED.
    Also has a % off coupon for you to use.
    Last edited: Sep 12, 2019
  3. KG7WGX

    KG7WGX XML Subscriber QRZ Page

    If you put the battery outside, it will not be at room temperature and its useful capacity will be sharply reduced.

    Unless you live in a modern home where the weatherstripping is so tight you can't light a wood stove unless you open a window, there is enough air exchange to handle battery gassing during charging. PROVIDED that the charge controller does a tapered charge, essentially terminating (or floating) the charge at a voltage appropriate for the type of battery. I believe the Epic PWR Gate does this.

    Charging at the correct rate does not create hydrogen or oxygen (see explanation below) :

    Chemical Reaction for Recharging

    The chemical reaction that takes place when the lead-acid battery is recharging can be found below.


    2e– + PbSO4(s) + H3O+(aq) –> Pb(s) + HSO4– + H2O(l)


    PbSO4(s) + 5H2O(l) –> PbO2(s) + HSO4–(aq) + 3H3O+(aq) + 2e–

    While recharging, the automobile battery functions like an electrolytic cell. The energy required to drive the recharging comes from an external source, such as an engine of a car. It is also important to note that overcharging of the battery could result in the formation of byproducts such as hydrogen gas and oxygen gas. These gases tend to escape from the battery, resulting in the loss of reactants.

    Check the electrolyte level periodically so you don't damage the plates.

    If there is any possibility of the house completely losing heat, the battery may be damaged if it is discharged and then allowed to freeze.
    K4AGO likes this.
  4. VE3KNT

    VE3KNT Ham Member QRZ Page

    I live in a old apartment building, no way to have the battery outside. Turned out to be a real dump, I already plan to move soon as the lease is up. This a "lowLoss PWRgate" sound alike name... no tech support and not a lot of specs posted. I disconnected the old battery yesterday to fine it at some point vented, one fuse holder that was laying on top of the battery had a corner of it partly dissolved.. and a little moisture in the bottom on the battery box. Got to get some baking soda and clean that up. the plan is to go get a new batter of some sort tomorrow (I wasn't feeling up to going out today) and drop the old battery off as the exchange casting. So I am having my doubts how good the LLPWRgate is now. but that battery is 7+ years old. the damage had to have happened in the last 2 or 3 months, I don't visually check it very often, it's kind of hard for me to get under the desk were it was.. And I've noticed it's been slowly loosing voltage capacity over time.
  5. KG7WGX

    KG7WGX XML Subscriber QRZ Page

    I used to go through deep-cycle batteries for my boat until I invested in a proper charger which would change from constant current to topping and then to float. I was overcharging the batteries and ruining the plates. The proper charger paid for itself in one year.

    As batteries are expensive, I suggest getting a good charger first. Then you can get the most life possible out of any battery you might use, whether it is a new one or something from a golf cart. ;)
  6. W9KEY

    W9KEY XML Subscriber QRZ Page

    As stated, he is not using a real West Mountain Epic PWRgate - unclear what charge profile is used.

    I trust your equations are correct, but speaking from first-hand experience - you don't want to be anywhere near an exploding lead-acid battery! Had one blow up in a stored classic car several years ago. Charger was accidentally disconnected during the winter and battery was receiving a full charge prior to first start of the season. A spark ignited the outgassed hydrogen and pieces of the battery (and acid) ended up more than 50 feet away. Anyone in the path of destruction would certainly have been seriously injured and/or blinded. The explosion was ear shattering and probably would have blown windows out of the garage (if I had windows) and if the door had been closed. Then the acid flow ate the seal-coating off my blacktop driveway.

    In summary, I'd be damn careful if I ever decided to put a lead-acid battery in my shack / or in the house ---- actually (now that I think about it) I never would.
  7. VE3KNT

    VE3KNT Ham Member QRZ Page

    Here's the link to the LowLossPWRGate

    I've seem some ham power their radio directly to a battery and run a battery tender all the time, instead of a big power supply.
    So I was considering one of these..

    Safety is always my biggest concern, and I should have stopped using car batteries for backup ages ago. There's a lot of power failures here, and sitting with nothing to do is no fun.. That's why I post stuff like this to see if there's a better way to do it.
  8. N8AFT

    N8AFT Ham Member QRZ Page

    Gassing or not, safe bet is not to have a lead-acid batt in the house, period.
    EVERY garage variety Battery Charger I have ever came across charges at over 14.4vdc.
    This is WHY I insist on charging and periodic maintenance of my batts using a regulated DC supply.... Battery mfrs will list the suggested Stable Level voltage chg range for your battery. If not, ask them for it. If they are clueless then you need to find a better builder of battery.
    Last edited: Sep 13, 2019
  9. VE3KNT

    VE3KNT Ham Member QRZ Page

    ok, this is what they sold me today, 32AH...
    Comments, suggests? Did I get something good?

    IMGP2127.JPG IMGP2128.JPG IMGP2130.JPG

    Attached Files:

  10. N8AFT

    N8AFT Ham Member QRZ Page


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