You don’t. It would be a high capacity charger.
FLA’s off-gas when charged. They need to be vented out.
For inside you need sealed - SLA, GEL, AGM. Or lifepo4. ?
Last time looked, Sam’s had Duracell gc2’s for$105. ?
LifePO4 vs sealed acid battery......LVD
- Thread starter French_guy
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FLA’s off-gas when charged. They need to be vented out.
For inside you need sealed - SLA, GEL, AGM. Or lifepo4. ?
Last time looked, Sam’s had Duracell gc2’s for$105. ?
French_guy
New Member
I realized I somehow asked the same question twice..................sorry
So 6V GC2 should/must be SLA/VRLA since they will be in the basement. Something like this:
www.samsclub.com
Since I will need 2 in series, I could also go with 2 x 100Ah marine battery in parallel for approximately the same wattage:
www.samsclub.com
Price would be approximately equivalent..........is there an option better than the other one (GC2 vs RV/Marine)?
So 6V GC2 should/must be SLA/VRLA since they will be in the basement. Something like this:
Duracell AGM Golf Car Battery, Group Size GC2 - Sam's Club
Buy Duracell AGM Golf Car Battery, Group Size GC2 : Golf Cart Batteries at SamsClub.com
www.samsclub.com
Duracell AGM Marine Battery, Group Size 27M - Sam's Club
Buy Duracell AGM Marine Battery, Group Size 27M : Marine Batteries at SamsClub.com
www.samsclub.com
French_guy
New Member
Looking at this GC2 battery on Sam's Club:
www.samsclub.com
What does that mean exactly:
Duracell Golf Car Battery, Group Size GC2 - Sam's Club
Buy Duracell Golf Car Battery, Group Size GC2 : Golf Cart Batteries at SamsClub.com
www.samsclub.com
What does that mean exactly:
- 20 amp hour rate:215
- 5 amp hour rate:157
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You can only use half the rating, maybe 70% with agm or gel. Plate sulfation is less with those.
Check their weight - usually gc’s have a lot more lead in them, and are much more durable, more cycles.
It is common for campers to replace failed marine/rv 12’s with the golf carts - they way outlast them.
Lead bats sag a lot with a heavy load - best for low draw or intermittent use. Lots of golf carts are 24v, so they have 4 bats to share the load. Drive stop, repeat. Recharge after 18 holes. ?
Check their weight - usually gc’s have a lot more lead in them, and are much more durable, more cycles.
It is common for campers to replace failed marine/rv 12’s with the golf carts - they way outlast them.
Lead bats sag a lot with a heavy load - best for low draw or intermittent use. Lots of golf carts are 24v, so they have 4 bats to share the load. Drive stop, repeat. Recharge after 18 holes. ?
French_guy
New Member
This is from the Rolls Battery website:
They seem to say it's for 50% DOD (10.5V), when you say I can use only half of the rating.....?
I'm confused now.....
They seem to say it's for 50% DOD (10.5V), when you say I can use only half of the rating.....?
I'm confused now.....
Horsefly
Solar Wizard
10.5V for lead acid is NOT 50% DoD. 10.5V is effectively DEAD, i.e. 100% DoD.
French_guy
New Member
Right..............confusion is gone now
50% DOD would be ~12V, correct?
MisterSandals
Participation Medalist
Interesting wording "on a battery that is under load".
When folks here talk about SoC, its almost always at rest. So maybe they figure that during "their" capacity testing, the voltage sag to 10.5V is how they want to represent it.
When folks here talk about SoC, its almost always at rest. So maybe they figure that during "their" capacity testing, the voltage sag to 10.5V is how they want to represent it.
That is the consensus here from what i've seen.
Or half their rating -190Ah is about 85-90Ah useable. If you weight it down a lot the voltage will sag. Set cutoff 11.5 or something, or get more batteries.
I had two GC’s, replaced them with 230A lifepo for at least double the useable capacity. ?
I had two GC’s, replaced them with 230A lifepo for at least double the useable capacity. ?
French_guy
New Member
It's frustrating..............LiFePO4 are apparently not ideal for standby solutions. The reviews about the Duracell GC2 batteries are not so great.
So at the end, I'm not sure what to buy !
So at the end, I'm not sure what to buy !
French_guy
New Member
OK, fair enough
When I look on Amazon, each battery have reviews going from "Awesome" to "junk"......!
I see more batteries under $300 now, or more "well known" (Chins, Li Time, Redodo, Weize) with coupons.
But all of them have reviews ranging from 5 stars to 1
So what would be a good pick in the $300 range? Cheaper is always better, but I don't want to buy a piece of crap to save $30 bucks
Does anyone have ever heard of "Goldenmate" batteries?
Amazon is a crap shoot.
I had to go back to the beginning to review the application...wow three months ago and still deciding?
You still need to decide your charging process for a standby application. For LFP I would pick one Will has reviewed with a positive result.
For sump pump standby I would go 12V agm with a good smart charger like a NOCO. Cheap and done. How many times a year does it run on battery? And how long does it need to run? You've done the energy analysis/assessment?
I had to go back to the beginning to review the application...wow three months ago and still deciding?
You still need to decide your charging process for a standby application. For LFP I would pick one Will has reviewed with a positive result.
For sump pump standby I would go 12V agm with a good smart charger like a NOCO. Cheap and done. How many times a year does it run on battery? And how long does it need to run? You've done the energy analysis/assessment?
French_guy
New Member
Yes, still deciding (procastinating?) - I haven't travelled much since then, so I still have time. And I still have my Yuasa batteries
3 months ago, I thought LFP, but then got advices that it was not the best for sump pump backup (standby applications)
I thought 2 x 6V GC2 would then be "ideal" (and I don't mind building a vented battery box for flooded acid batteries) but of course AGM would make is easier (GC2 but expensive, or "regular" batteries)
You recommended a Duracell battery (post #37) but reviews for Duracell batteries are not all great....
Deciding about the charging process: regardless of the battery type, I will invest in a decent charger (IOTA+IQ4 for flooded acid, Meanwell or Victron for LiFePO4 or AGM, etc...)
If LiFePO4 is fine for standy application, I was thinking the Weize battery reviewed by Will:
If LiFePO4 is NOT recommended, then it will have to be 6V golf cart batteries (most likely flooded since AGM GC2 are much more expensive) or 12V AGM..............but other than Duracell at Sam's Club or Batteries+, I'm not sure what would be a good choice. And like I said, Duracell's reviews are not so great
About how many times per year it runs on battery: not really often in the last 10 years....it's clearly a backup / "piece of mind" for me
How long does it need to run: same thing, hard to predict. If it happends when I'm around, it will need to run for few hours until I come back home. If it happens when I'm out of town (vacation or business trip)............then it's another story and I don't believe any system will be 100% "flood proof"
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Do people complain about Duracell batteries because they’re defective? Or because the user doesn’t know what they’re doing?
Top battery brands:
Crown
Trojan
Optima
Oddessy
Rolls surrette
Lifeline
Crown is a top pick - not so expensive but good quality and reputation. Trojan too. Optima is super popular for power sports, oddessey too. Lifeline for marine.
I was getting 7 years out of the cheapest Costco batteries you could buy. 65lbs of lead, keep ‘em charged. ?
Most users don’t properly care for batteries, then complain when they fail.
Top battery brands:
Crown
Trojan
Optima
Oddessy
Rolls surrette
Lifeline
Crown is a top pick - not so expensive but good quality and reputation. Trojan too. Optima is super popular for power sports, oddessey too. Lifeline for marine.
I was getting 7 years out of the cheapest Costco batteries you could buy. 65lbs of lead, keep ‘em charged. ?
Most users don’t properly care for batteries, then complain when they fail.
French_guy
New Member
Thank you Browneye...
Yes, I will agree with you that some reviews should be taken with a grain of salt....They don't know what they do, and trash the product in their reviews
About LFP, I just noticed Walmart is selling the CHINS 100Ah for $267 (and the 200Ah for $549) - At this price, it doesn't have the low temp protection, but being in my basement, I don't need it
At $267, a 100Ah LFP makes sense as well (2 x 6V GC2 will be in the same price range if not more, for the equivalent capacity)
And there ya go...a ten-twenty year battery. 
Just get a proper charger for it, cuz you don't want to trickle a LFP.
Worth noting - the Meanwell chargers don't re-boost. Which might be fine if you're going to manually reset it when/if it gets used.
I'm not that familiar with the victron IP ones. There may be other options. You don't need a high-current charger for a standby battery. A 10A would be fine. But it needs to terminate charge when reaches your full setting - likely at about 14.2V or so. They're full then and need to stop charging. You could float at 13.4V to maintain, wouldn't hurt it.
Just get a proper charger for it, cuz you don't want to trickle a LFP.
Worth noting - the Meanwell chargers don't re-boost. Which might be fine if you're going to manually reset it when/if it gets used.
I'm not that familiar with the victron IP ones. There may be other options. You don't need a high-current charger for a standby battery. A 10A would be fine. But it needs to terminate charge when reaches your full setting - likely at about 14.2V or so. They're full then and need to stop charging. You could float at 13.4V to maintain, wouldn't hurt it.
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French_guy
New Member
Was thinking this one:
Or this one:
www.trcelectronics.com
Or this one:
NPB-450-12 - MEAN WELL - TRC Electronics
Order MEAN WELL NPB-450-12 battery chargers on-line or call today for exceptional customer service. TRC is the USA stocking headquarters of MEAN WELL NPB-450-12 Battery Chargers. NPB-450-12 is ready to ship today.
www.trcelectronics.com
French_guy
New Member
What do you mean by "don't re-boost"?And there ya go...a ten-twenty year battery.
Just get a proper charger for it, cuz you don't want to trickle a LFP.
Worth noting - the Meanwell chargers don't re-boost. Which might be fine if you're going to manually reset it when/if it gets used.
I'm not that familiar with the victron IP ones. There may be other options. You don't need a high-current charger for a standby battery. A 10A would be fine. But it needs to terminate charge when reaches your full setting - likely at about 14.2V or so. They're full then and need to stop charging. You could float at 13.4V to maintain, wouldn't hurt it.
Victron has a 10A and 15A chargers as well:
In 2-stage on the Meanwell, once the battery reaches the set max voltage charging terminates. It doesn't automatically restart the charge cycle if the battery drops - it has to be power-cycled.
I have not studied the Victron programming, but they make good stuff, and the BT interface is really good. Also about twice the price.
I have not studied the Victron programming, but they make good stuff, and the BT interface is really good. Also about twice the price.
