This bit From a recent post went unnoticed and the post moved on from the original subject. I am interested in this and decided to re-post.

The context here is the possibility of using several identical smart chargers to charge several batteries in series at the same time using a generator to power the chargers. This author gave his opinion.

I've also seen some people suggest separate small, inexpensive 12V chargers for each battery. This will perform the same type of balancing as BMS or multi-bank chargers.

I have seen this too. How does one go about isolating each individual battery for this?

most of the newer smart chargers are isolated...note the most not all.

You don't have to isolate the batteries when charging, as long as the entire bank is being charged at once.

You can imagine that applying a single 12V charger to part of your battery pack will never complete charging the battery that it is hooked up to because the other batteries that are not charging would be adding load. In this situation, the hooked up battery would be taking considerable abuse by having all the current flowing through it to the other discharged batteries.

But if you had a separate 12V charger attached to each battery, charging all at once, each battery has enough autonomy, even while wired in series, to allow the charger to select the charging phase according to that battery's needs. So the first battery to the constant current cutoff would start the constant voltage phase with decreasing amps, even while it's neighbor was still taking full amps. You won't get much cross battery flow since they are all in a charging phase and should be close to the same voltage. Once all the batteries get to the constant voltage phase, there won't be any cross flow, because there is no voltage difference. As each charger drops into the float phase, reduced voltage and amps, there will be some minor cross flow, but since the amps are down across the entire pack, the amount of current flow should be negligible. As long as one charger is pushing current, all of the batteries would stay at a higher than resting voltage, but not really getting any more charge. Once the last charger shut off, the whole pack would return to it's resting voltage.

While there is some room for a massively out-of-balance battery to confuse some of the chargers, this strategy will keep the batteries top balanced by tailoring the charge to each battery, so a dramatically out-of-balance situation would be rare. If you noticed that one charger ran consistantly longer than the others, it would indicate a failing cell. This is similar to noting that one battery never hit peak voltage and starting shunting with BMS.

This is why the multi-bank chargers, hooked up to individual batteries that are connected in series (like ours) or parallel (house batteries in RV's and boats) work so well in keeping the batteries in balance.

Eric

Hydraulic advice needed :  I want to use a open center control valve in conjunction with a hydraulic motor that is down stream from the valve. In other words the fluid would pass through the open center valve and on to the motor. The idea is the control valve could act as a bypass to stop the motor if needed by shorting the fluid directly back to the reservoir. I am not a hydraulic person but it seems to me the open center would not restrict or cause unwanted reactions from the motor.

Also the valve I have in mind has a built in relief valve but I suspect it is designed to protect the spool valve and would not function with what I have in mind.

Looking to rebuild a Lister SL1. I sent the crank off to the shop. They say the crank is off  by .002.  They couldn't find the tolerance limit for this engine and suggested that being off that much would kill the oil pressure. I wonder if with a new bearing that .002 would be acceptable.as far as the  oil pressure is concerned.