Good Adjustible Stepped Charger 10-15a

[rgleason]

I am looking for a good inexpensive adjustible stepped charger for deep cycle FLA, agm, gel, lfp etc. to replace my old simple Guest chargepro 10 for occassional automatic winter use to fully charge my batteries

OR should I just get a 60a sterling procharge and remove it from the boat each fall?

[Pete7]

I was going to suggest a small Sterling PRO charger until you said LFP, which probably rules out most of the current chargers. Give up the LFP requirement then fine, or the equivalent CTEK.



However, your comment about a 60A charger is also a concern, how big is this battery bank?

Will this charger be used as a power pack to run lots of 12v items whilst your plugged into shore power. Finally why do you think it needs to be taken home for the winter? my Sterling Digital is permanently wired in and stays on board all year round.

[john61ct]

Could just use a Power Supply if you or the BMS are terminating charging, no stages required.

But you do need to set your own voltage for LFP.

Sterling ProCharge Ultra and ProMariner Pronautic P let you do that, not sure what their lower current ones are.

They also let you derate amps if you want to keep current low.

[rgleason]

Thanks, all. I just threw LFP in there for the future. If it is cheap enough and works properly, charging to 100%, it won't matter.

I mentioned Sterling pro 60a because it was considering house loads while charging LFP 200-300 ah bank fast, but I think 40a would fine.

[john61ct]

It is the lack of user customizable voltage setpoints that makes that model unsuitable.

Yes amps output is irrelevant for both FLA and LFP if you have all the time in the world to get the energy back in.

But running off a genny you want to limit runtimes, thus a charger capable of handling its max output, but also capable of being de-rated, is optimal.

[Emouchet]

Size the charger amps outputto be about 10% of the bank capacity. i.e. 30amps for 300 amps/h capacity.

10 amps for LFP is a non sense, considering the LFP will take all the currents they can out of the charger. the 10 amps charger will run full performance, increasing wear faster than you think.

[john61ct]

Originally Posted by Emouchet

Size the charger amps outputto be about 10% of the bank capacity. i.e. 30amps for 300 amps/h capacity.

Bit higher is faster even for FLA. AGM needs lots more .2-.4C minimum.

> 10 amps for LFP is a non sense, considering the LFP will take all the currents they can out of the charger. the 10 amps charger will run full performance, increasing wear faster than you think.

Yes since OP said cheap, that is a concern that the mfg skimps on overcurrent protection.

But if not, the only downside is slower charge times.

[rgleason]

My 1999 Guest Charge Pro 2612A 10 amp Charger, on (2) Trojan 6vdc T105 (series) shuts off prematurely and only charges them up to 83% capacity. This resulted in a terrible PSOC problem and has resulted in the possible loss of at least one pair of T105 batteries.

I wrote Marinco about this and the response was:

"I am sorry to say based on the age of the unit I can not do anything for warranty on it. My guess due to the age the Capasitors inside are drying up and not able to do the same output as they used to."

Does not spell capacitors correctly either... What is "drying up"? I think capacitors work or they don't. I think it is more about the voltage/current sense circuit.

[john61ct]

Have to say I'm surprised you're even trying, what 20 years later? Wasn't that great even when new.