Renogy Batteries

[nmt]

Hey all, anyone have experience with Renogy batteries? Thinking of getting these https://www.renogy.com/deep-cycle-agm-battery-12-volt-200ah/ for house bank and bow thruster. Could I also use one for a starting battery for a Lehman 120? They seem to be the most affordable AGMs I’ve found. Want AGMs because batteries are right under salon in engine room.

[catalinajack]

Originally Posted by nmt

Hey all, anyone have experience with Renogy batteries? Thinking of getting these https://www.renogy.com/deep-cycle-ag...12-volt-200ah/ for house bank and bow thruster. Could I also use one for a starting battery for a Lehman 120? They seem to be the most affordable AGMs I’ve found. Want AGMs because batteries are right under salon in engine room.

What advantage do you see, for your use case, for AGM batteries vs flooded?

[nmt]

Main one for me is that flood lead acid batteries are not supposed to be used in living spaces because of off gassing during charging and these are right below the salon. As I understand it (not an expert), they can also be discharged to 80% and have the same or better cycle life as a flooded acid battery discharged to 50%. So more usable capacity.

[Comodave]

Originally Posted by nmt

Main one for me is that flood lead acid batteries are not supposed to be used in living spaces because of off gassing during charging and these are right below the salon. As I understand it (not an expert), they can also be discharged to 80% and have the same or better cycle life as a flooded acid battery discharged to 50%. So more usable capacity.

Then you need to do much much more homework. If you are not completely sure what you are doing get a certified marine electrician to help you design the battery system.

[nmt]

AGM is not Lithium. It’s a sealed lead acid battery.

[Action]

Newbie comment, isn't the ER supposed to be vented with forced air?

As in run the blower for some minutes before running engines.

[Comodave]

Originally Posted by Action

Newbie comment, isn't the ER supposed to be vented with forced air?

As in run the blower for some minutes before running engines.

Blowers are required in gas boats, and they suck air out from low in the engine room. Blowers are not required in diesel boats.

[mvweebles]

No experience with their batteries, but had stupendously awful experience with them as a company. Inverter arrived clearly DOA (throwing over-temp error in 50-degree ambient temps). You have no idea the hoops they sent me through to RMA. Ultimately required a BBB complaint and credit card dispute. Still had to dog them for 2 months to actually pay

If you buy, do it via Amazon. But seriously, in a world of poor customer service and tech support, they really stand out in my mind. Waste of time.

Peter

[Action]

Well at least I learned something today!!!!

[Terry Jackson]

Damn, already bought Renogy AGM 12V 100 Ah battery and 100W solar panel kit (which includes 30A PWM Battery Solar Charge Controller). Hope I have better luck with Renogy than mvweebles did!
I Also have the Vevor 2.500 kW pure sinewave inverter (fridge, microwave) , and Jupiter 2kW quasi sinewave inverter (lights, heater).
I was (maybe naively) wondering if anyone had run the two inverters in parallel with success off the common 100Ah battery (low enough battery impedance).
For emergency use only in kitchen of house
Thanks, Terry

[Comodave]

Originally Posted by Action

Well at least I learned something today!!!!

That is a nice thing about diesels, we don’t have to have ignition protected electrical devices like a gas boat requires.

[mvweebles]

Originally Posted by Terry Jackson

Damn, already bought Renogy AGM 12V 100 Ah battery and 100W solar panel kit (which includes 30A PWM Battery Solar Charge Controller). Hope I have better luck with Renogy than mvweebles did!
I Also have the Vevor 2.500 kW pure sinewave inverter (fridge, microwave) , and Jupiter 2kW quasi sinewave inverter (lights, heater).
I was (maybe naively) wondering if anyone had run the two inverters in parallel with success off the common 100Ah battery (low enough battery impedance).
For emergency use only in kitchen of house
Thanks, Terry

I have a couple solar panels I bought 5 years ago from renogy that work fine, and a DC-DC charger, and a pretty nice MPPT controller that ingests both solar and engine Alternator. All before my disaster experience. Their tech support, if needed, is pretty bad - days between responses, and the responses were often wrong (telling me my 12.4V FLA batteries were dead and needed to be replaced before they'd replace the 12v inverter).

If it works, great. If it needs to go back, do so asap. That's my experience.

Peter

[Flatswing]

Originally Posted by nmt

Main one for me is that flood lead acid batteries are not supposed to be used in living spaces because of off gassing during charging and these are right below the salon. As I understand it (not an expert), they can also be discharged to 80% and have the same or better cycle life as a flooded acid battery discharged to 50%. So more usable capacity.

Many boats (including mine) safely have FLA batteries in the ER below the main salon. The engine room is vented anyway and FLA still delivers the most AHrs for your dollar compared with AGM & Lithium per Jim Healey over on the MTOA & AGLCA forums.
I agree in sleeping spaces, best to use AGM (that’s I what I use for my thrusters) but two 4 D’s cost more than my 1100 AHr FLA housebank.

[Comodave]

Originally Posted by Flatswing

Many boats (including mine) safely have FLA batteries in the ER below the main salon. The engine room is vented anyway and FLA still delivers the most AHrs for your dollar compared with AGM & Lithium per Jim Healey over on the MTOA & AGLCA forums.
I agree in sleeping spaces, best to use AGM (that’s I what I use for my thrusters) but two 4 D’s cost more than my 1100 AHr FLA housebank.

Our last boat also.

[nmt]

Helpful info all! Thank you.

Hmm, engine room doesn’t seem very ventilated tbh but maybe I’m missing something

[ranger58sb]

Originally Posted by nmt

Main one for me is that flood lead acid batteries are not supposed to be used in living spaces because of off gassing during charging and these are right below the salon. As I understand it (not an expert), they can also be discharged to 80% and have the same or better cycle life as a flooded acid battery discharged to 50%. So more usable capacity.

Don't know about that brand, but...

If your batteries are in living spaces, and/or access for service is difficult, there's a good use case for AGMs. Not sure engine room batteries needs the same attention as batteries in living living spaces. Check your venting, though...

That 80% discharge thing is probably a tad aggressive. Odyssey says that in some of their literature, but then I think their thousand-cycle chart (similar to what Lifeline publishes) still suggests longest life if you usually discharge to no less than 50%.

Sailboat cruisers (cruisersforum.com) point out that AGMs don't do well if not routinely/often brought back up to 100% charge... which many have difficulty doing (unless they have solar) 'cause they don't have access to shore power very often. That has not been an issue for us...

We have been using Odyssey and Lifeline AGMs. Usually Odyssey when we need to emphasize cranking amps, Lifeline when we want to emphasize capacity. Track record for Odysseys has been 11 and 12 seasons for the banks we had the longest. Don't have enough time with Lifelines to confirm similar lifetime, though...

I'd say you might be looking at a brand where you get only what you pay for.

-Chris

[catalinajack]

Originally Posted by nmt

Main one for me is that flood lead acid batteries are not supposed to be used in living spaces because of off gassing during charging and these are right below the salon. As I understand it (not an expert), they can also be discharged to 80% and have the same or better cycle life as a flooded acid battery discharged to 50%. So more usable capacity.

AGMs are leaad batteries. They pwrform no differently than flooded lead acid batteries. Depleting them often to 80% will sugnificantly shorten their life.

[Bacchus]

This below from the Trojan Users Guide...
The 50% DOD cliff where exceeding it somehow damages batteries is a myth
Yes you get fewer (large AH) cycles but the alternative is more (smaller AH cycles)... it is essentially a wash (within 10%).
Consider the case where you run your bank to 40% discharge daily. 365 cycles / yr with continuous use
Now compare recharging every other day... 80% DOD 183 cycles / year with continuous use.
Many will say you lose 50% of your "life" with higher discharge... per above ( approximation) it's a wash but in the rough order of magnitude for many batty life cycle charts... losing 50% of cycles for a 2X DOD.

[SteveK]

Originally Posted by Bacchus

This below from the Trojan Users Guide...
The 50% DOD cliff where exceeding it somehow damages batteries is a myth
Yes you get fewer (large AH) cycles but the alternative is more (smaller AH cycles)... it is essentially a wash (within 10%).
Consider the case where you run your bank to 40% discharge daily. 365 cycles / yr with continuous use
Now compare recharging every other day... 80% DOD 183 cycles / year with continuous use.
Many will say you lose 50% of your "life" with higher discharge... per above ( approximation) it's a wash but in the rough order of magnitude for many batty life cycle charts... losing 50% of cycles for a 2X DOD.Attachment 137275

Thanks for posting this. I had this thought often, having depleted batteries more than 50% and still getting years of service from them. Explained like this it all makes sense.

[ranger58sb]

Originally Posted by Bacchus

Consider the case where you run your bank to 40% discharge daily. 365 cycles / yr with continuous use
Now compare recharging every other day... 80% DOD 183 cycles / year with continuous use.

Yes, there's trade-off, but...

Consider a battery that predicts 1500 cycles to 40%, 1000 cycles to 50% DoD... but only 550 at 80%. (Lifeline Technical Manual, Rev G., 11/26/2019, p40. Understanding that lab predictions aren't real world...)

Using a 100 Ah battery for example, that'd be 50K used amps versus 44K used amps. I think.

-Chris