New Trojans: Looking for advice on initial charge

[hammick]

I am picking up eight Trojan L16P batteries tomorrow. They are 420ah (C20) and have a manufacture date of June 2015.

I am going to borrow a large cart type charger from a friend. Pretty sure it has manual settings as well as an auto mode and will also charge 6v batteries.

Shall I just charge them at 40a on the auto mode and be done or should I do a manual equalization? If I should manually equalize at what amps and for how long. I left my hydrometer at the barn where they will be installed which is a couple days drive so I won't have a hydrometer to check until I get them installed.

Thanks for any advice.

[Willy T]

Without a Hydrometer it doesn't make much sense to do a EQ in the blind. I'd check the electrolyte level in all cells, add distilled water if necessary and do a full charge with the absorb amp's dropping to 2 % of capacity. It's going to take 20-50 cycles for the plates to fully form anyway and there is not much consistency of capacity or SG level till then. It never hurts to stir the electrolyte and the absorb should do that. Once you get them installed you can start working with the SG level, again it will be a bit erratic in the beginning so don't over EQ them. Nice long deep cycles and long absorbs work better.

[hammick]

My only option for six volts is 50a. Is that OK to use? It's a manual charger with a timer. Old school.

[Willy T]

My only option for six volts is 50a. Is that OK to use? It's a manual charger with a timer. Old school.

The amps are fine, but if it doesn't have a reliable amp meter built in or you don't have a clamp on meter it'll be hard to know when you get to the ending amps. You can put two series together and use 12v if you have a better selection for a charging source.

[inetdog]

You can get a clamp-on DC ammeter from Sears for about $50, and it will be well worth it with that many batteries. What will the bank voltage be? (How many batteries in series and in parallel).
Keep in mind that the Trojan batteries will not deliver their full rated capacity for at least 10-20 discharge/charge cycles during normal use. Plan on bringing them down to 80% SOC or lower for those initial charging cycles, even if it means going for two days before charging.

[hammick]

It will be a 48v bank (eight L16Ps in series).

I plan to use a shunt with a monitor rather than a clamp on meter.

I have two Interstate GC2 batteries on our trailer with a BlueSky Energy CC and 160w panel to learn the ropes.

It took them a few cycles and absorption charges to get full capacity.