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Heavy Duty Trucks (Class 7/8).

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    • I just think if I invested such a HUGE amount in multiple Lithium batteries I would want them ALL BALANCED the best possible, even if sure what Glenn proposed will work fine and Im sure a bunch out there (maybe most systems) are wired how he intends or even worse lol  Best wishes Glenn, Im sure you will have one fine system regardless  John T  Hey I don't claim to have my system all wired perfect either grrrrrrrr just giving what I consider a good answer   Glenn PS to your post above  "John I still had a #4 on the battery that difficult to get to. So what I did was hook up negative side with #4 from each battery to shunt" MY RESPONSE  Iffffffffff you have 3 separate cables, preferably all the same length, from EACH battery Negative to your shunt THATS NOT THE SAME AS ALL NEGATIVES DAISY CHAINIED AND YOU TAP IN THE MIDDLE WITH A SINGLE CABLE TO THE SHUNT   That's sounding more like Smart Gauges Methods 3 or 4 which "may" be fine, but Im unsure exactly how you're wired so just take a look at the Smart Gauge website and Im sure you will figure it out............. 
    • Glenn my observations agree with John T.  Small differences multiply over time especially in lithium batteries where there are small differences in  voltage for various SOC.  In your case it seems you have ample battery so maybe a loss of capacity isn't a problem and different wiring may suffice.
    • John I still had a #4 on the battery that difficult to get to. So what I did was hook up negative side with #4 from each battery to shunt. My bms max out at 100 amps each. So total of 300 amps of 48v. Actual voltage is 58v. My positive side is currently daisy chained with 2/0. Hooked up shunt with dual #2/0.  My change back with 3 individual hots to buss bar. I was hooking up my victron smart shunt. Little disappointed in it. Sitting in living room my phone don't connect to it. Have to go to bedroom directly over it to get signal. Move to living room and loose it.
    • Glenn, FYI here’s what the Smart Gauge tests results indicated and what THEY had to say about the differences as to how multiple batteries are connected. These are NOT my calculations so if anyone has a disagreement take it up with them not me. THEIR (not mine) results show it indeed makes a significant difference as to load and charge balance versus the method of connection.  AGAIN sure it still works EITHER way its just that if you want all batteries to share the load and charging the same you may want to at least consider how you wire them…  ITS YOUR CHOICE NONE OF OURS  SMART GAUGE TEST RESULTS AND THEIR CONCLUSIONS.          Now in all fairness, many people say "but the difference is negligible, the resistances are so small, so the effect will also be small". The problem is that in very low resistance circuits (as we have here) huge differences in current can be produced by tiny variations in battery voltage. I'm not going to produce the calculations here because they really are quite horrific. I actually used a PC based simulator to produce these results because it is simply too time consuming to do them by hand.  METHOD 1 Battery internal resistance = 0.02 Ohms Interconnecting lead resistance = 0.0015 Ohms per link Total load on batteries = 100 amps The bottom battery provides 35.9 amps of this. The next battery up provides 26.2 amps. The next battery up provides 20.4 amps. The top battery provides 17.8 amps. METHOD 2 After this simple modification, with the same 100 amp load.... The bottom battery provides 26.7 amps of this. The next battery up provides 23.2 amps. The next battery up provides 23.2 amps. The top battery provides 26.7 amps. METHODS 3 AND 4 (to achieve even better balance with multiple batteries) NOT SHOWN HERE, GO TO THEIR WEBSITE for all test results SmartGauge Electronics - Interconnecting multiple batteries to form one larger bank Best wishes Glenn, you asked the question and I gave an answer, now its up to you….and  either still "works" even if not the best balance........  NOTE I support your or anyone's decision to wire however they please. I cant say I have always done things the absolute best  perfect way and you should connect them however its best for YOUR situation be it prefect or almost prefect or questionable lol. Go for it its YOUR money YOUR batteries none of ours......Im only here to help the best i can...   John T Retired n rusty electrical engineer so no warranty  
    • Since the kitchen is on the slide, and our slide has a slight backward tilt when extended, the water in the coffee maker is always higher in the back of the holding tank, and butter in a pan will go away from me, but it is so slight that it doesn't bother me.  The slide topper still collects water in a heavy rain and we have to be very care to bring it in slowly so no one around gets a shower.   Hasn't been a problem as we haven't seen real rain in Western Washington since June 14th!   They even have a heat advisory out for Seattle area for tomorrow and Tuesday as it will be in the high 80s for those days!    We just grin at our relatives complaining about the heat. 😎
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