Need to replace Genset Battery: can I upgrade to AGM or Lithium?

[Old_Skewler]

I need a new 12V battery starter for my Genset, my old one died in the winter. I currently have a 50W Panel connected to a Renogy Wanderer 10 Amp solar charger.

I was wondering if I could "upgrade" the Genset battery from Lead-Acid battery to AGM or Lithium and ALSO use it for USB lighting or add a small inverter.
I just want to make sure the upgrade battery will be able to also crank the genset, a 14kW Kohler unit.

Any thoughts?

 

[sunshine_eggo]

AGM is the more sensible choice. Lithium is often unable to accommodate the high draw of a starter motor. There are lithium batteries designed for starter applications, but they tend to be very expensive.

Additionally, a starter battery is going to be held at full charge for an extended period - this is not particularly desirable for LFP as they can degrade when held at 100% SoC especially in elevated temps.

Given that the generator is essentially emergency equipment, I would hesitate to hang any drain on the starter battery unless the generator is already running... which kinda makes pulling power off the starter battery even less logical.

 

[Old_Skewler]

AGM is the more sensible choice.

Understood, I will check AGM batteries as a replacement.

Given that the generator is essentially emergency equipment, I would hesitate to hang any drain on the starter battery unless the generator is already running... which kinda makes pulling power off the starter battery even less logical.

My intent was to have a USB lighting connected to this system to illuminate the path and/or the outhouse. I don't have the actual load but it seems relatively small and I am banking on the 50W PV panel to keep things charged.

Am I on the right track here?

 

[sunshine_eggo]

It's about the load. Just make sure the numbers check out.

 

[onokai]

also Lithium batteries need a specifuic charger and the AGM will take whats already in the setup

 

[Browneye]

I would not even bother with an AGM - a sealed lead acid would work fine there. If you want some redundancy get a group 27, they're bigger than standard batteries. If it's for a gen-start, a regular starting battery kept fully charged would be my choice.

Everybody got all enamored with agm's and how great they are - but really their strength is for racing, offroad, boats, etc.; where they can be mounted in any direction, can stand a lot of shock without degrading, and do not vent. As far as power, they're only mildly better than standard lead acid, at generally twice the price. YMMV

 

[onokai]

I love my agm is my boats
Browneye has some good points
the best point for an agm is not adding water in hot climates on a land based application in my view

 

[sunshine_eggo]

also Lithium batteries need a specifuic charger and the AGM will take whats already in the setup

This is not at all a true statement. The vast majority of lead-acid chargers work fine on LFP.

 

[onokai]

I was refering to this about lead acid chargers- so there is some truth to it-I just googled it.

You can use a lead acid charger on a lithium battery if you want, HOWEVER, you must NOT use a lead-acid charger if it has an automatic “equalisation mode” which cannot be permanently turned off.

 

[sunshine_eggo]

I was refering to this about lead acid chargers- so there is some truth to it-I just googled it.

You can use a lead acid charger on a lithium battery if you want, HOWEVER, you must NOT use a lead-acid charger if it has an automatic “equalisation mode” which cannot be permanently turned off.

Sorry. Wrong again, especially in this context.

also Lithium batteries need a specifuic charger and the AGM will take whats already in the setup

Nope.

Chargers with automatic equalization cycles are rare, and the LFP battery would protect itself. A charger like that is even MORE risky for AGM and GEL as equalization will damage them.

 

[onokai]

Two wrongs make a right ? So all this talk I read about lithium boat batteries need the new style chargers is crap? The batterys are

LiFePO4​

 

[sunshine_eggo]

Important to be able to distinguish between technical information and marketing.