Digital Voice Essentials Home Phone 1.0 - Type A vs Type B - Safety Issue?

[Graham888]

I have just installed four of these phones and am very pleased with their performance. However I have just discovered that two of the phones are Type A and the other two are Type B. Their respective 'Let's get started' manuals are identical apart from the small print on the back page, which states 'EDHP 1.0 Type A' or  'EDHP 1.0 Type B'. However the following extracts from BT's PDF at  https://www.bt.com/content/dam/bt/help/digital-voice/essential-phone/BT-Essential-Digital-Home-Phone...  reveals that there is an important difference in their power supply units:

Power cable and plug
Item code 090713 – Type A
Item code 092132 – Type B

2 rechargeable batteries
Already in handset
(AAA NiMH 800mAh – Type A)
(AAA NiMH 850mAh – Type B)

Important
Only use the mains power adaptors, cables and rechargeable batteries supplied in this box or this product might not work. Any replacement rechargeable batteries must be of the same type. BT accepts no responsibility for damage caused to your Essential Digital Home Phone if you use any other type of batteries.

Question:
With four of these phones in my house and several family users,  it will be impossible to maintain association of their installed batteries with the appropriate Type A or Type B charger. I would therefore like to know if such mixing is a safety issue?

[Les-Gibson]

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@Graham888wrote:

... it will be impossible to maintain association of their installed batteries with the appropriate Type A or Type B charger. I would therefore like to know if such mixing is a safety issue?

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Why is it impossible?

Each of the handsets has its own ID. Simply tell the users that (e.g) Handsets 1 and 2 are to be recharged downstairs and handsets 3 and 4 upstairs

[imjolly]

personally I don't think it will make any difference which phones are connected to which bases as long as the power supply is connected to the correct phone base charger

[Graham888]

Thank you for your suggestion, however from the information given in BT's PDF it's important for the handset batteries to be matched to the correct type of power supply.  Although the bases look identical they all have labels underneath identifying them as Type A or Type B, hence my concern about safety in the event of a handset being placed on the wrong type of base.

[Graham888]

Unfortunately such disciplined behaviour is impossible in my house.

[imjolly]

I know that would not bother me as I am sure the base chargers will work on either battery but it is your choice

[Gary_C]

Humm
The type A has a 6V 400mA output which suggests its not just a simple trickle C/~100 charger (cant find any spec for the type B, what does it say on the plug ?), overcharging a NiHM battery isn't ideal but given they are so close, I bet it won't make any difference.

[Graham888]

Thanks for helping with this issue.

The Type B plug label states:

6.0V   0.6A   3.6 W

[barnpiece · Accepted solution]

I have one Digital Voice Essential marked Type A and one marked Type B.

Only one base (Type B) is used to charge (the other does not have its power supply connected), and I swop the phones over ever 12 hours so they spend half the time on charge. The reason I do this is that many years ago a BT engineer told me that the batteries will last much long if allowed to discharge in this way (and it is true).

I have been using these two phones for over 1.5 years now with no problem (and I didn't know until now that they had diffferent ratings).

Richard

[Graham888]

Your response leads me to think that there isn’t a safety issue, so thank you for that.  However it does beg the question of why BT warns against mixing in their online manual?   I don’t know if BT monitors this community, but it would be great if one of their engineers gave an explanation. Meanwhile I am happy to accept your response as a solution, so thanks again.