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BurbMan
Explorer II
Feb 25, 2022

Venting Batteries in 5er Basement?

Our new-to-us 5er has one group 24 battery in a front side compartment with the hydraulics for the slide mechanisms. It's in a vented box with a hose that exits the front of the camper.

In our previous TT we had a pair of GC-2's mounted on the tongue that worked well for us. Only had a 150w PSW inverter for TV/laptop, etc. Converted all the lights to LED so the only real power hog is the furnace. Always wanted another pair of GC2's but had nowhere to put them in the TT.

I was thinking of going to a pair of LiFePO batteries, but based on comments from an earlier thread will probably stay with the GC2's. I've got plenty of storage now in the 5er but need to vent the battery bank if I install in the basement.

Looking for ideas/suggestions on battery boxes or setups on how you vented 2 pairs of GC-2s.
  • I installed a rv dryer vent on a battery storage door for venting.
  • BurbMan wrote:
    The negative comments were related to the battery in my link above....if I went lithium, these would be the ones in my budget range, and were dismissed as having inferior/unreliable BMS software.


    BurbMan,

    Nothing wrong with Li until 0 C (32 f). Then dendrites may easily form.

    There is one Li subset called Lithium Titinate that can be used in the cold. I got a quote for a single 100 amp-hour jar. It was a mere $1890.00 (cdn).

    Here are the "straight good" from an Li seller:

    https://www.solacity.com/how-to-keep-lifepo4-lithium-ion-batteries-happy/

    The highlights from the above are:

    "To sum up, for long and happy LFP battery life, in order of importance, you should be mindful of the following:

    Keep the battery temperature under 45 C (113 f) (under 30C if possible (86 f)) – This is by far the most important!

    Keep charge and discharge currents under 0.5C (0.2C preferred)

    Keep battery temperature above 0 C (32 f) when discharging if possible

    – This, and everything below, is nowhere near as important as the first two

    Do not cycle below 10% – 15% SOC unless you really need to

    Do not float the battery at 100% SOC if possible

    Do not charge to 100% SOC if you do not need it"
  • Veebyes wrote:
    Lithium would be the way to go however AGM or Gel batteries are fine for enclosed places. In the marine world there is no way for venting batteries through the bottom. Breaks the #1 rule in Boating i.e. keep the water on the outside.

    In cruising boats AGM or Gel Cell are the battery type of choice though the trend is most likely headed to lithium just like the RV world.

    Battery banks are located all over in boats. If there is no room in the engine compartment they may be located in space located in the cabin area somewhere. No venting, no problem.


    Batteries don't typically need venting in a marine application because the off gassing of concern is hydrogen. Since hydrogen is lighter than air, it rises up and out of the engine compartment, which isn't air tight as air needs to get in to feed the engines.

    If you put them in the living space, it needs venting but a poorly sealed lid can be enough.
  • When going to AGM or Lithium batteries. You need to VERIFY that your RV Power Converter or Inverter/Charger can charge AGM or Lithium batteries correctly. NOT doing that and if NOT capable of correctly charging AGM/Lithium batteries will result in failed batteries and you have wasted Hundreds of dollar's on batteries. Doug
  • Yeah, that is a 4D case size. Same size as the AGM that I have. I have a 'Lifeline' brand. US made I believe. On my second one. First one gave me 9 years. Happens to fit just right on my 5er battery tray.

    One of the best attributes is that it does not lose much in storage. Typically I put mine into storage, battery disconnected, at the end of October & it remains untouched till mid April. In 2019-2020 it sat from end of October till beginning of August untouched & had power to run landing legs without charging first. Pleasant surprise.
  • BurbMan wrote:
    The negative comments were related to the battery in my link above....
    Yeah, probably best to stay away from the cheapest thing you can find.
  • agesilaus wrote:
    I know, that's why I was considering them, but based on negative feedback from a previous thread on these, I'm back to looking at GC2's.


    Battleborn posted a comparison video, AGM vs GC2 vs Lithium and to their dismay found that the GC2 was the most cost efficient. They did their best to hide those results but they did not delete them.
    Lithium on makes cost sense if you keep them more than many years, which few people do. How many sets of GC2 can you buy for the price of one set of Lithium


    GC2 is the most cost efevtive if you buy sams club cheep ones and your only talking about one purchase. if you buy quality GC2 batteries your up in the ball park for LFP when you look at usable AH, for exmple a GC2 rolls surrette (one of the best 6V deep cycles you can get) is 450 each, so 900 bucks to get 265AH of 12V so based on life thats 132.5AH usable for 800-1000 cycles. for 900 cdn I can buy 300AH 12V LFP in a DIY format (including buying a quality BMS and the stuff to build it) . far cheeper not even taking longjevity into account as over twice the usable AH or I could buy two 100AH comercial sold 100AH batteries, which still have more AH and life than the GC2's. if I go with the cheepest option up here that would be costco at 150 each for 208 AH so 104 usable for max life which will most likly be about 600-800 cycles. do to get 200 usable AH you need 4 so thats 600 bucks which is only 300 bucks off the set up above. and I havent even talked about the 3-4000 cycles you get from the Li to justify the long term cost comparison. the price has dropped enough that you can do Li cheeper than quality alternaitives. I never understood why people always have to find the cheepst brand they can and compare it to a quality then nd say well I can buy two or three of thoes for this price... what about the work uying new ones , changing them out, inconveniance when they **** the bed while your camping (which is normaly when you find the issue) and so on. do you do that with tools , I can buy 10 of these wrenches for the price of that one...... theres usaly a reason for stuff like that...
  • dougrainer wrote:
    When going to AGM or Lithium batteries. You need to VERIFY that your RV Power Converter or Inverter/Charger can charge AGM or Lithium batteries correctly. NOT doing that and if NOT capable of correctly charging AGM/Lithium batteries will result in failed batteries and you have wasted Hundreds of dollar's on batteries. Doug
    I have very little hands-on experience charging an AGM, but do have a bit of experience charging lifepo4's.

    One of the things we've discovered after building/using/testing a few lifepo4 cell packs over the last year, is that most any quality, late model 3-stage 13.2v/13.6v/14.4v lead cell converter will charge a 12v lifepo4 battery/pack safely, with zero downsides.

    There's nothing special about most "lithium approved" converter/chargers except the slightly higher bulk charge voltage (typically 14.6v). So what's the advantage to charging a 12v lifepo4 at a slightly higher voltage (=> 14.6v) vs. 14.4v? Surprisingly, there's very little to no advantage. It's common knowledge that 12v lifepo4 batteries suffer negative effects when subjected to =>14.6v when at 100% SOC for long periods of time. Why risk it. In fact, this is exactly what single-stage 14.6v lithium converters/chargers can potentially do, since they do not, cannot, drop to a lower float/absorption voltage. They subject a 12v lifepo4 battery to 14.6v indefinitely. This can potentially overcharge (and permanently damage) a 12v lifepo4 battery. No such risk with a 3-stage 14.4v lead-cell converter/charger: 1) they have a safer, lower bulk charge voltage, and 2) they will drop into 13.2v/13.6v float/absorption mode once max. SOC has been reached at 14.4v

    For those who would prefer to upgrade to a lithium approved converter/charger, I'd suggest staying away from any single-stage lithium converter/charger. A multi-stage lithium converter/charger (and 3-stage lead-cell converter/charger) is a much safer choice because they both drop to a lower float/absorption voltage (typically 13.6v) after the 12v lifepo4 battery has reached 100% SOC---no chance of overcharging.

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