4-12 volt btys to 6-8 volt btys

[tlr6334]

I was told by a dealer that going to 6-8volt btys would take a specfic OBC depending on which battery one used. That is If you chose a Trojan bty you would need model x, if you chose US bty you would need model y etc. The reason I ask this question is there are after market kits out there to change over to 8 volt btys and they do not include an OBC in their kit. I've read somehere, I believe Tahoe Dawg stated that the OBC must be changed upon doing the conversion. So is this the case and are their different OBC's versions for different bty types?

[shadowman]

i havn,t heard that yet but david would know for sure............................

[Colbyntx]

There are different OBC for specific batteries. If you did the conversion from your 4X12 setup, your current OBC would work but you would not get full potential out of your 8v batteries. It is best to get the correct OBC. I don't think you would need a specific OBC for US vs Trojans though.

[Stevegrmich]

I seem to recall David mentioning in another thread that one would need to change out the OBC when moving from 4-12v's to 6-8v's . . . but as mentioned, I have never heard/read about battery specific OBC's . . .

[driver33b]

I am in the same boat...l have just installed 6x8v into 05 Precedent. There is not much info regards which OBC to use....from what I've been able to find CC seem to just upgrade the OBC version when better technology/understanding occurs.

If you look for replacement OBCs they seem to list the latest model to replace all versions listed before it. Supposedly the latest version for 6x8v in Precedents has a better algorithm to optimise the charge....some claiming 20-25% better charge/holding performance ......whatever that means?

[driver33b]

A bit more research of the 2008 Precedent parts list shows that on page 197 it lists 12v Ventmaster batteries uses Version 3.0 as the OBC....page 211 lists OBC ver. 4.0 fits both 4x12v and 6x8v..... batteries listed are 12v Ventmaster and 8v Trojan batteries on the new battery tray/configuration.

Hope this answers your question....or at least explains part of why someone could say the OBC is battery related.

[tlr6334]

Tahoe Dawg,
I just completed a conversion for a friend of mine, but left the old OBC. This is a 2005 Precedent. Trojan 12 volt btys were replaced with Trojan 8 volt btys. What happens if we leave the old OBC and should have I replaced the OBC with the newer upgraded version. Simply put, we wre trying to control cost,
Thanks,
Tommy

[TahoeDawgZ71]

Originally Posted by driver33b

A bit more research of the 2008 Precedent parts list shows that on page 197 it lists 12v Ventmaster batteries uses Version 3.0 as the OBC....page 211 lists OBC ver. 4.0 fits both 4x12v and 6x8v..... batteries listed are 12v Ventmaster and 8v Trojan batteries on the new battery tray/configuration.

Hope this answers your question....or at least explains part of why someone could say the OBC is battery related.

That's correct. But that book was printed in 2008. It's changed numerous times since then.

[TahoeDawgZ71]

Originally Posted by tlr6334

Tahoe Dawg,
I just completed a conversion for a friend of mine, but left the old OBC. This is a 2005 Precedent. Trojan 12 volt btys were replaced with Trojan 8 volt btys. What happens if we leave the old OBC and should have I replaced the OBC with the newer upgraded version. Simply put, we wre trying to control cost,
Thanks,
Tommy

Yes you should. You're not going to get full capacity of the 8V batteries with the old school 12V OBC.

[TahoeDawgZ71]

Originally Posted by tlr6334

I believe Tahoe Dawg stated that the OBC must be changed upon doing the conversion. So is this the case and are their different OBC's versions for different bty types?

Yes there are. Trojan and Crown = Algorithm 1, US Battery = Algorithm 2. I wouldn't be too concerned with it though. This was something that was started by US battery. They wouldn't honor their battery warranty if the OBC wasn't calibrated to charge "their" batteries the way "They" wanted to. I personally think as an individual owner you may not ever notice a difference, but yes they do exist.