Lithium deep cycle vs AGM and which is a GOOD brand

Suggest you use your favourite search engine for information about the 2 battery types.

As to your last question re which brand is good ... I'm no industry expert, so will not recommend any brand. I have however had exceptional service from Peter at Battery Value (search for it). Website not the most sophisticated ... but the customer service for me has been outstanding, and I've bought 3 different types/brands of AGM batteries from him over the years for different vehicles/purposes and all are still in service and performing well ... some now more than 10 years old. Every battery is supplied with its test/analysis report he has done personally before supplied to you. I once had a need to collect a battery after hours from his home based workshop and can attest to him being a genuine independent operator that is well set up to specialise in this field. Suggest calling him to discuss your needs - I see he is now selling AGMs and Lithiums.

(Mods - I apologise in advance if I've breached any rules in mentioning the name of a business. I did look up the rules, and as I have no connection to the business, just a happy customer, I thought it was OK).

If your AGM died, I would be doing some resarch to find out why before simply replacing it.
They don't normally just die without an external reason which will still be there and may also destroy the replacement.
As far as AGMs Vs Lithium batteries, there are very specific advantages for lithium, but they are also less tollerent to abuse which is more expensive, so refer again to point 1.
Cheers,
Peter
OKA196 motorhome

Hi Spiro,

The difference between LiFePo4 batteries and AGM batteries is well documented. A search on this and other forums including “Google” will reveal all.

Having said that, the biggest advantage of LiFePo4 of AGM is the weight saving. LiFePo4 batteries are half the weight of AGM AmpHr for AmpHr. Next is longevity, one term testing has shown that LiFePo4 batteries have a cycle time in excess of 5,000 cycles. Whilst some AGMs do have similar cycle length, they still fall short in the weight category. Thirdly, LiFePo4 batteries can safely be taken doesn’t to 15% SOC (State of Charge) without effecting their longevity, and will still deliver in excess of 12 volts at this SOC. AGM batteries do not like being taken down below 50% SOC without having some effect on their longevity. Also, at 50% SOC, an AGM will only just be a one 12 volts, and will drop below 12 volts once you start going below 50% SOC.

The biggest draw back with LiFePo4 batteries over AGM is the initial cost outlay. Although there are some very cheap LiFePo4 batteries around, you need to be wary as some of these batteries are made up of “second life” cells. These are cells that have been in service on other systems like uninterrupted power supply back up batteries, that have been replaced. These battery cells may still be fine and deliver in excess of 12 volts, but may only be 80% efficient.

Macca.