General Boards > General Discussion

Battery Equalization

(1/2) > >>

Fred Brooks:
   Now that we are beginning to see light at the end of the tunnel, we may want to consider visiting our coach so we don't experience any surprises. One of the more common situations will be the house batteries. For a lot of us they have been sitting dormant for over a year. Even though Beaver owners are the smartest on the planet, we should check our house batteries out even if the coach was plugged in or solar charged.
   Deep cycle batteries will leave a small sulfate deposit on the lead plates over time and the acid mixture will stratify from sitting too long. After checking water levels, and charging them up to "float then full" I would suggest that you give them a "hydrometer test" to see what state they are in. A fully charged lead acid battery should read 1.265 specific gravity (at 80 degrees). You can purchase a hydrometer for under $10.00 at any NAPA parts store. If your test is less than specified and you have not "equalized" your batteries recently, here is how you can do this yourself. In the Inverter/charger owners manual under "charging", you will find Bulk, Absorption, Float, then Equalization. Enclosed is a picture of how I do it to keep the process under control. This sequence will make the batteries boil a little as the voltage rises. Read the instructions and initiate the process from your Inverter/charger remote panel. After you are done, wipe down the batteries with baking soda solution then clean and protect the terminals. Doing this per your instructions will extend your house batteries life. Happy trails to all of us. Fred

Eric Maclean:
Fred
Equalisation is a great idea to help equalize all the cells in a given battery bank but you should keep an eye on the chassis batteries while doing it if you have an Echo charger or some sort of battery combiner as often they will combine both battery banks at higher charge voltages and the chassis batteries are usually of a different age or even different type of batteries .
This can sometimes lead to over charge damage to the chassis batteries depending on the equalisation duration and voltage.
The chassis batteries need to be included in the electolite level check and should be monitored for signs of over charging
 ( excessive boiling or sulpher smell) during equalisation.
I personally have seen several chassis battery sets boiled  dry from lack of maintenance and a couple of good equalisation charges.
My coach has 4 x 6 volt flooded lead acid golf cart batteries for the coach and a pair of maintenance free 31S chassis batteries as many of these coaches do
The problem arises from the miss match of battery type as they may have different Internal impedence or resistance values which makes the bank with the lower impepence value excepts the charge much more readily than the other bank leading to over charging of the lower impedence batteries.
This is the same reason you should not mix new and old batteries in a given battery bank.

I don't want to confuse the topic I still believe in equalisation of the coach batteries because as you said it will help extend their life. Just be aware of the chassis batteries and the possible effects on them if they are combined  with different types of batteries during equalisation.
Hope this helps
Eric

Fred Brooks:
   Eric, Good point and thanks for sharing as I agree with you. What I forgot to mention is you can take the Echo charger out of the loop by removing the fuse from the yellow holder with the red wire with the yellow tracer (chassis battery charge line) until you are done. Fred

Bill Lampkin:
Our coach has the 'Bird' relay-doesn't that keep the two battery banks separated if both are fully charged? Correct me if I don't have this right.

Eric Maclean:
Bill
The B.I.R.D  or bidirectional isolator relay delay is actually the electronic module which operates the isolator relay/solenoid we commonly refer to as the bird
the electronics are set up to keep the two battery banks seperate to preserve the chassis batteries from being depleted when drawing down the coach batteries while dry camping. the BIRD electronics monitor both the chassis battery side of the relay and the coach battery side of the relay and when either side shows a charge voltage say from the engines alternator on the chassis side or from the inverter or even solar on the coach side the electronics turns the relay solenoid on connecting both battery banks together so they can be charged all together. The e!ectronics have a delay built in to allow the charge system to stabilize before connecting the second battery bank to avoid voltage pull down which could cause the relay to drop out or bounce or chatter.
As long as there is a good charge voltage present on either battery bank the solenoid should be closed connecting the two battery banks together.
Hope this helps
Eric

Navigation

[0] Message Index

[#] Next page