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DwnSth's avatar
DwnSth
Explorer
Oct 10, 2016

New batteries loosing charge quickly

Just installed two Sam's club (eveready) 6volt batteries to replace the two 12v marine batteries. All seemed good with set-up at home. Let new batteries charge through on-board converter for a couple of days. Unplugged to see how things looked. Held 12.7 volts for most of day using a few lights and other small amp draws throughout the day. Next day showing 12.6 volts. Plugged in my Renogy 100 watt portable solar panels on a fully sunny day. By end of day with solar disconnected showing 12.8 volts. Held charge at 12.7 volts by end of second day fully disconnected and no additional charger. Nothing but radio standby and whatever other small amp draws might be active for detectors etc. Traveling yesterday had Fridge on gas. and batteries were fully charged when leaving. After 8 hour drive, dummy lights show one tick...lights when on but plugged in right away. Didn't have my meter available to check actual voltage. This really concerns me, never seen one tick on the dummy lights and new supposedly better 6v 220 amp hour batteries should not have been depleted anywhere near this quick. Any ideas? Could the batteries be bad...what can I do to test. I'm going to pick-up a hydrometer today but hoping for other advice also. BTW, my converter is the basic WFCO 9865. Thinking this may be part of problem since it never really does a boost charge (but my solar does).

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  • BFL13's avatar
    BFL13
    Explorer II
    Oct 10, 2016
    The 14.2 Iota Vabs is better than the 13.6 Vabs of the regular PowerMax for faster charging.

    However, it would still be an "issue" when recharging, eg, my AGM battery which specifies being recharged at around 14.6 and even wants that level maintained with temperature compensation.

    "Regular" converters are all compromise designs in some fashion, so just be sure the specs for YOUR battery will be ok with whichever converter you choose. OR get the adjustable voltage kind and you can meet any battery spec.

    But as smk says, be prepared also to be there when needed to do the voltage adjustments. (Which does not mean baby-sitting it. Just be there when it is time to change it down from Vabs to Float.)
  • time2roll's avatar
    time2roll
    Nomad
    Oct 10, 2016
    IOTA does not drop to 13.6 volts at the first trigger. It goes to 14.2 volts and still provides a good charge relative to Powermax at 13.6

    The charging graphs I have seen posted puts IOTA and PD about dead even at four hours charging.

    Yes go a little big if you get PD due to the amps that sag. Likewise go a little small on the IOTA to avoid wire voltage drop issues that cause early step down to 14.2 volts.

    Avoid the regular Powermax for generator charging. Must get the manually controlled unit and be willing to manage as such.
  • BFL13's avatar
    BFL13
    Explorer II
    Oct 10, 2016
    MEXICOWANDERER wrote:
    Way back when I repeatedly recommended TOP CHARGING brand new batteries. Here is an example why. With the newer SMART "You Can't Get There From Here" chargers, this is another example of why I continue to fume.

    I'll ask this question another way: Some of the newer gizmos have been reported to charge at 14.8 volts for a "limited time". Is there any way to switch them off then back on and repeat the 14.8 volt cycle?


    Yes, the PowerMax and Iota will do 15 minutes of "boost" when restarted. I don't have an Iota, but I notice that with the PowerMax, to get it to repeat boosting every 15 minutes you have to wait after shutting it off for the caps to bleed off DC voltage as shown at the converter DC output terminals. This only take a minute but if you restart before the DC voltage bleeds off, it won't go back to boost but just carry on where it left off.
  • MEXICOWANDERER's avatar
    MEXICOWANDERER
    Explorer
    Oct 10, 2016
    Way back when I repeatedly recommended TOP CHARGING brand new batteries. Here is an example why. With the newer SMART "You Can't Get There From Here" chargers, this is another example of why I continue to fume.

    I'll ask this question another way: Some of the newer gizmos have been reported to charge at 14.8 volts for a "limited time". Is there any way to switch them off then back on and repeat the 14.8 volt cycle?
  • BFL13's avatar
    BFL13
    Explorer II
    Oct 10, 2016
    Any brand converter will do for being on shore power. On generator you want a fast charge and will be doing only 50-80s or the like, then letting solar do as much as it can in the rest of the daylight time to get the SOC higher.

    Fast charging means getting the batteries up to say 14.8v and holding that voltage the whole time until the batteries are recharged. Then you drop to 13.6ish as the Float voltage. So which converter does that? None of them.

    However, if you get an "adjustable voltage" model, you can set 14.8 and it will stay there until you change it to some other voltage. Perfect for generator recharging and you can also set it to 13.6 for when on shore power.

    Two 6s can take around 75 amps as the initial charging rate (75/232 = 32% ) so your best choice is a 75 adjustable voltage converter like this

    http://www.bestconverter.com/Boondocker-BPCM-75-75-Amp-Adjustable-Power-ConverterCharger_p_587.html#.V_vKI0cVBpw

    If you don't like that, then a PD70 with Charge Wizard would be second best choice (but maybe cheaper in cost) because you can hit the CW button and keep it at 14.4 (there is a 14.8v version) but it does not hold rated constant amps so well in bulk, which means it will take longer to do the recharge.

    The regualar Iota and PowerMax converters drop to a Float( lower) voltage "too soon", so they will take longer to do a recharge, and generator run time is what counts.
  • time2roll's avatar
    time2roll
    Nomad
    Oct 10, 2016
    Add the charge line. Upgrade your converter.

    Also the GC2 batteries need to get a few cycles on them to reach full capacity. WFCO will chronically undercharge the battery.

    If you cannot get that done in 3 days... the solar will have to save you.
    Need to be extra conservative with battery power.
  • DwnSth's avatar
    DwnSth
    Explorer
    Oct 10, 2016
    No charging from vehicle in this set-up. At least not supposed to be, vehicle power only running lights and jack but no charging at all to TT batteries. Will know better this afternoon when I pick up hydrometer. Getting ready to maybe order a new converter. The converters look like an easy install, is that true? Don't want to get myself in over my head while actually on trip. Have seen many suggestions for the PD, what about the boondocker converter? Do need the batteries working, in 3 days I will be boondockng for 14 straight days. Had hoped the new batteries and solar would limit generator use.
  • SoundGuy's avatar
    SoundGuy
    Explorer
    Oct 10, 2016
    DwnSth wrote:
    Traveling yesterday had Fridge on gas. and batteries were fully charged when leaving. After 8 hour drive, dummy lights show one tick...lights when on but plugged in right away. Didn't have my meter available to check actual voltage. This really concerns me, never seen one tick on the dummy lights and new supposedly better 6v 220 amp hour batteries should not have been depleted anywhere near this quick. Any ideas? Could the batteries be bad...what can I do to test.


    Hollow complaint if you don't know for a fact that your truck's charge line is working properly ... that's your first step, before assuming anything. If you don't have truck voltage on Pin 4 of it's Bargman connector relative to ground (Pin 1) then you're drawing down your batteries as you drive, not maintaining their charge. :R
  • BFL13's avatar
    BFL13
    Explorer II
    Oct 10, 2016
    The converter would bring them to 13.6v and with full batteries, after unplugging from shore power you would see 13.x volts for quite a while before losing the surface charge and seeing 12.7.

    So is your converter working at all?

    Driving is from 7-pin, not converter so unless you had 120v shore power or generator, the converter had nothing to do with it while you were away.

    No idea why the one light. Maybe it got left out when you wired up your new battery set? Could be lots of things. You need the portable voltmeter and an hydrometer to check things out.
  • time2roll's avatar
    time2roll
    Nomad
    Oct 10, 2016
    DwnSth wrote:
    Traveling yesterday had Fridge on gas. and batteries were fully charged when leaving. After 8 hour drive, dummy lights show one tick...lights when on but plugged in right away.
    You better check your vehicle charging system is sending power to the batteries.

    And yes if you do any off-grid camping replace the WFCO with PD or IOTA.

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